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Further restructure ext4 documentation; fix up ext4's delayed 

allocation for bigalloc file systems; fix up some syzbot-detected
 races in EXT4_IOC_MOVE_EXT, EXT4_IOC_SWAP_BOOT, and ext4_remount; and
 a few other miscellaneous bugs and optimizations.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:

 - further restructure ext4 documentation

 - fix up ext4's delayed allocation for bigalloc file systems

 - fix up some syzbot-detected races in EXT4_IOC_MOVE_EXT,
   EXT4_IOC_SWAP_BOOT, and ext4_remount

 - ... and a few other miscellaneous bugs and optimizations.

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
  ext4: fix use-after-free race in ext4_remount()'s error path
  ext4: cache NULL when both default_acl and acl are NULL
  docs: promote the ext4 data structures book to top level
  docs: move ext4 administrative docs to admin-guide/
  jbd2: fix use after free in jbd2_log_do_checkpoint()
  ext4: propagate error from dquot_initialize() in EXT4_IOC_FSSETXATTR
  ext4: fix setattr project check in fssetxattr ioctl
  docs: make ext4 readme tables readable
  docs: fix ext4 documentation table formatting problems
  docs: generate a separate ext4 pdf file from the documentation
  ext4: convert fault handler to use vm_fault_t type
  ext4: initialize retries variable in ext4_da_write_inline_data_begin()
  ext4: fix EXT4_IOC_SWAP_BOOT
  ext4: fix build error when DX_DEBUG is defined
  ext4: fix argument checking in EXT4_IOC_MOVE_EXT
  ext4: fix reserved cluster accounting at page invalidation time
  ext4: adjust reserved cluster count when removing extents
  ext4: reduce reserved cluster count by number of allocated clusters
  ext4: fix reserved cluster accounting at delayed write time
  ext4: add new pending reservation mechanism
  ...
This commit is contained in:
Linus Torvalds 2018-10-24 17:42:24 +01:00
parent d6edff78fe 33458eaba4
commit 5993692f09
44 changed files with 1985 additions and 1170 deletions
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574
Documentation/admin-guide/ext4.rst Normal file
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@ -0,0 +1,574 @@
.. SPDX-License-Identifier: GPL-2.0
========================
ext4 General Information
========================
Ext4 is an advanced level of the ext3 filesystem which incorporates
scalability and reliability enhancements for supporting large filesystems
(64 bit) in keeping with increasing disk capacities and state-of-the-art
feature requirements.
Mailing list: linux-ext4@vger.kernel.org
Web site: http://ext4.wiki.kernel.org
Quick usage instructions
========================
Note: More extensive information for getting started with ext4 can be
found at the ext4 wiki site at the URL:
http://ext4.wiki.kernel.org/index.php/Ext4_Howto
- The latest version of e2fsprogs can be found at:
https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/
or
http://sourceforge.net/project/showfiles.php?group_id=2406
or grab the latest git repository from:
https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git
- Create a new filesystem using the ext4 filesystem type:
# mke2fs -t ext4 /dev/hda1
Or to configure an existing ext3 filesystem to support extents:
# tune2fs -O extents /dev/hda1
If the filesystem was created with 128 byte inodes, it can be
converted to use 256 byte for greater efficiency via:
# tune2fs -I 256 /dev/hda1
- Mounting:
# mount -t ext4 /dev/hda1 /wherever
- When comparing performance with other filesystems, it's always
important to try multiple workloads; very often a subtle change in a
workload parameter can completely change the ranking of which
filesystems do well compared to others. When comparing versus ext3,
note that ext4 enables write barriers by default, while ext3 does
not enable write barriers by default. So it is useful to use
explicitly specify whether barriers are enabled or not when via the
'-o barriers=[0|1]' mount option for both ext3 and ext4 filesystems
for a fair comparison. When tuning ext3 for best benchmark numbers,
it is often worthwhile to try changing the data journaling mode; '-o
data=writeback' can be faster for some workloads. (Note however that
running mounted with data=writeback can potentially leave stale data
exposed in recently written files in case of an unclean shutdown,
which could be a security exposure in some situations.) Configuring
the filesystem with a large journal can also be helpful for
metadata-intensive workloads.
Features
========
Currently Available
-------------------
* ability to use filesystems > 16TB (e2fsprogs support not available yet)
* extent format reduces metadata overhead (RAM, IO for access, transactions)
* extent format more robust in face of on-disk corruption due to magics,
* internal redundancy in tree
* improved file allocation (multi-block alloc)
* lift 32000 subdirectory limit imposed by i_links_count[1]
* nsec timestamps for mtime, atime, ctime, create time
* inode version field on disk (NFSv4, Lustre)
* reduced e2fsck time via uninit_bg feature
* journal checksumming for robustness, performance
* persistent file preallocation (e.g for streaming media, databases)
* ability to pack bitmaps and inode tables into larger virtual groups via the
flex_bg feature
* large file support
* inode allocation using large virtual block groups via flex_bg
* delayed allocation
* large block (up to pagesize) support
* efficient new ordered mode in JBD2 and ext4 (avoid using buffer head to force
the ordering)
[1] Filesystems with a block size of 1k may see a limit imposed by the
directory hash tree having a maximum depth of two.
Options
=======
When mounting an ext4 filesystem, the following option are accepted:
(*) == default
ro
Mount filesystem read only. Note that ext4 will replay the journal (and
thus write to the partition) even when mounted "read only". The mount
options "ro,noload" can be used to prevent writes to the filesystem.
journal_checksum
Enable checksumming of the journal transactions. This will allow the
recovery code in e2fsck and the kernel to detect corruption in the
kernel. It is a compatible change and will be ignored by older
kernels.
journal_async_commit
Commit block can be written to disk without waiting for descriptor
blocks. If enabled older kernels cannot mount the device. This will
enable 'journal_checksum' internally.
journal_path=path, journal_dev=devnum
When the external journal device's major/minor numbers have changed,
these options allow the user to specify the new journal location. The
journal device is identified through either its new major/minor numbers
encoded in devnum, or via a path to the device.
norecovery, noload
Don't load the journal on mounting. Note that if the filesystem was
not unmounted cleanly, skipping the journal replay will lead to the
filesystem containing inconsistencies that can lead to any number of
problems.
data=journal
All data are committed into the journal prior to being written into the
main file system. Enabling this mode will disable delayed allocation
and O_DIRECT support.
data=ordered (*)
All data are forced directly out to the main file system prior to its
metadata being committed to the journal.
data=writeback
Data ordering is not preserved, data may be written into the main file
system after its metadata has been committed to the journal.
commit=nrsec (*)
Ext4 can be told to sync all its data and metadata every 'nrsec'
seconds. The default value is 5 seconds. This means that if you lose
your power, you will lose as much as the latest 5 seconds of work (your
filesystem will not be damaged though, thanks to the journaling). This
default value (or any low value) will hurt performance, but it's good
for data-safety. Setting it to 0 will have the same effect as leaving
it at the default (5 seconds). Setting it to very large values will
improve performance.
barrier=<0|1(*)>, barrier(*), nobarrier
This enables/disables the use of write barriers in the jbd code.
barrier=0 disables, barrier=1 enables. This also requires an IO stack
which can support barriers, and if jbd gets an error on a barrier
write, it will disable again with a warning. Write barriers enforce
proper on-disk ordering of journal commits, making volatile disk write
caches safe to use, at some performance penalty. If your disks are
battery-backed in one way or another, disabling barriers may safely
improve performance. The mount options "barrier" and "nobarrier" can
also be used to enable or disable barriers, for consistency with other
ext4 mount options.
inode_readahead_blks=n
This tuning parameter controls the maximum number of inode table blocks
that ext4's inode table readahead algorithm will pre-read into the
buffer cache. The default value is 32 blocks.
nouser_xattr
Disables Extended User Attributes. See the attr(5) manual page for
more information about extended attributes.
noacl
This option disables POSIX Access Control List support. If ACL support
is enabled in the kernel configuration (CONFIG_EXT4_FS_POSIX_ACL), ACL
is enabled by default on mount. See the acl(5) manual page for more
information about acl.
bsddf (*)
Make 'df' act like BSD.
minixdf
Make 'df' act like Minix.
debug
Extra debugging information is sent to syslog.
abort
Simulate the effects of calling ext4_abort() for debugging purposes.
This is normally used while remounting a filesystem which is already
mounted.
errors=remount-ro
Remount the filesystem read-only on an error.
errors=continue
Keep going on a filesystem error.
errors=panic
Panic and halt the machine if an error occurs. (These mount options
override the errors behavior specified in the superblock, which can be
configured using tune2fs)
data_err=ignore(*)
Just print an error message if an error occurs in a file data buffer in
ordered mode.
data_err=abort
Abort the journal if an error occurs in a file data buffer in ordered
mode.
grpid | bsdgroups
New objects have the group ID of their parent.
nogrpid (*) | sysvgroups
New objects have the group ID of their creator.
resgid=n
The group ID which may use the reserved blocks.
resuid=n
The user ID which may use the reserved blocks.
sb=
Use alternate superblock at this location.
quota, noquota, grpquota, usrquota
These options are ignored by the filesystem. They are used only by
quota tools to recognize volumes where quota should be turned on. See
documentation in the quota-tools package for more details
(http://sourceforge.net/projects/linuxquota).
jqfmt=<quota type>, usrjquota=<file>, grpjquota=<file>
These options tell filesystem details about quota so that quota
information can be properly updated during journal replay. They replace
the above quota options. See documentation in the quota-tools package
for more details (http://sourceforge.net/projects/linuxquota).
stripe=n
Number of filesystem blocks that mballoc will try to use for allocation
size and alignment. For RAID5/6 systems this should be the number of
data disks * RAID chunk size in file system blocks.
delalloc (*)
Defer block allocation until just before ext4 writes out the block(s)
in question. This allows ext4 to better allocation decisions more
efficiently.
nodelalloc
Disable delayed allocation. Blocks are allocated when the data is
copied from userspace to the page cache, either via the write(2) system
call or when an mmap'ed page which was previously unallocated is
written for the first time.
max_batch_time=usec
Maximum amount of time ext4 should wait for additional filesystem
operations to be batch together with a synchronous write operation.
Since a synchronous write operation is going to force a commit and then
a wait for the I/O complete, it doesn't cost much, and can be a huge
throughput win, we wait for a small amount of time to see if any other
transactions can piggyback on the synchronous write. The algorithm
used is designed to automatically tune for the speed of the disk, by
measuring the amount of time (on average) that it takes to finish
committing a transaction. Call this time the "commit time". If the
time that the transaction has been running is less than the commit
time, ext4 will try sleeping for the commit time to see if other
operations will join the transaction. The commit time is capped by
the max_batch_time, which defaults to 15000us (15ms). This
optimization can be turned off entirely by setting max_batch_time to 0.
min_batch_time=usec
This parameter sets the commit time (as described above) to be at least
min_batch_time. It defaults to zero microseconds. Increasing this
parameter may improve the throughput of multi-threaded, synchronous
workloads on very fast disks, at the cost of increasing latency.
journal_ioprio=prio
The I/O priority (from 0 to 7, where 0 is the highest priority) which
should be used for I/O operations submitted by kjournald2 during a
commit operation. This defaults to 3, which is a slightly higher
priority than the default I/O priority.
auto_da_alloc(*), noauto_da_alloc
Many broken applications don't use fsync() when replacing existing
files via patterns such as fd = open("foo.new")/write(fd,..)/close(fd)/
rename("foo.new", "foo"), or worse yet, fd = open("foo",
O_TRUNC)/write(fd,..)/close(fd). If auto_da_alloc is enabled, ext4
will detect the replace-via-rename and replace-via-truncate patterns
and force that any delayed allocation blocks are allocated such that at
the next journal commit, in the default data=ordered mode, the data
blocks of the new file are forced to disk before the rename() operation
is committed. This provides roughly the same level of guarantees as
ext3, and avoids the "zero-length" problem that can happen when a
system crashes before the delayed allocation blocks are forced to disk.
noinit_itable
Do not initialize any uninitialized inode table blocks in the
background. This feature may be used by installation CD's so that the
install process can complete as quickly as possible; the inode table
initialization process would then be deferred until the next time the
file system is unmounted.
init_itable=n
The lazy itable init code will wait n times the number of milliseconds
it took to zero out the previous block group's inode table. This
minimizes the impact on the system performance while file system's
inode table is being initialized.
discard, nodiscard(*)
Controls whether ext4 should issue discard/TRIM commands to the
underlying block device when blocks are freed. This is useful for SSD
devices and sparse/thinly-provisioned LUNs, but it is off by default
until sufficient testing has been done.
nouid32
Disables 32-bit UIDs and GIDs. This is for interoperability with
older kernels which only store and expect 16-bit values.
block_validity(*), noblock_validity
These options enable or disable the in-kernel facility for tracking
filesystem metadata blocks within internal data structures. This
allows multi- block allocator and other routines to notice bugs or
corrupted allocation bitmaps which cause blocks to be allocated which
overlap with filesystem metadata blocks.
dioread_lock, dioread_nolock
Controls whether or not ext4 should use the DIO read locking. If the
dioread_nolock option is specified ext4 will allocate uninitialized
extent before buffer write and convert the extent to initialized after
IO completes. This approach allows ext4 code to avoid using inode
mutex, which improves scalability on high speed storages. However this
does not work with data journaling and dioread_nolock option will be
ignored with kernel warning. Note that dioread_nolock code path is only
used for extent-based files. Because of the restrictions this options
comprises it is off by default (e.g. dioread_lock).
max_dir_size_kb=n
This limits the size of directories so that any attempt to expand them
beyond the specified limit in kilobytes will cause an ENOSPC error.
This is useful in memory constrained environments, where a very large
directory can cause severe performance problems or even provoke the Out
Of Memory killer. (For example, if there is only 512mb memory
available, a 176mb directory may seriously cramp the system's style.)
i_version
Enable 64-bit inode version support. This option is off by default.
dax
Use direct access (no page cache). See
Documentation/filesystems/dax.txt. Note that this option is
incompatible with data=journal.
Data Mode
=========
There are 3 different data modes:
* writeback mode
In data=writeback mode, ext4 does not journal data at all. This mode provides
a similar level of journaling as that of XFS, JFS, and ReiserFS in its default
mode - metadata journaling. A crash+recovery can cause incorrect data to
appear in files which were written shortly before the crash. This mode will
typically provide the best ext4 performance.
* ordered mode
In data=ordered mode, ext4 only officially journals metadata, but it logically
groups metadata information related to data changes with the data blocks into
a single unit called a transaction. When it's time to write the new metadata
out to disk, the associated data blocks are written first. In general, this
mode performs slightly slower than writeback but significantly faster than
journal mode.
* journal mode
data=journal mode provides full data and metadata journaling. All new data is
written to the journal first, and then to its final location. In the event of
a crash, the journal can be replayed, bringing both data and metadata into a
consistent state. This mode is the slowest except when data needs to be read
from and written to disk at the same time where it outperforms all others
modes. Enabling this mode will disable delayed allocation and O_DIRECT
support.
/proc entries
=============
Information about mounted ext4 file systems can be found in
/proc/fs/ext4. Each mounted filesystem will have a directory in
/proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
/proc/fs/ext4/dm-0). The files in each per-device directory are shown
in table below.
Files in /proc/fs/ext4/<devname>
mb_groups
details of multiblock allocator buddy cache of free blocks
/sys entries
============
Information about mounted ext4 file systems can be found in
/sys/fs/ext4. Each mounted filesystem will have a directory in
/sys/fs/ext4 based on its device name (i.e., /sys/fs/ext4/hdc or
/sys/fs/ext4/dm-0). The files in each per-device directory are shown
in table below.
Files in /sys/fs/ext4/<devname>:
(see also Documentation/ABI/testing/sysfs-fs-ext4)
delayed_allocation_blocks
This file is read-only and shows the number of blocks that are dirty in
the page cache, but which do not have their location in the filesystem
allocated yet.
inode_goal
Tuning parameter which (if non-zero) controls the goal inode used by
the inode allocator in preference to all other allocation heuristics.
This is intended for debugging use only, and should be 0 on production
systems.
inode_readahead_blks
Tuning parameter which controls the maximum number of inode table
blocks that ext4's inode table readahead algorithm will pre-read into
the buffer cache.
lifetime_write_kbytes
This file is read-only and shows the number of kilobytes of data that
have been written to this filesystem since it was created.
max_writeback_mb_bump
The maximum number of megabytes the writeback code will try to write
out before move on to another inode.
mb_group_prealloc
The multiblock allocator will round up allocation requests to a
multiple of this tuning parameter if the stripe size is not set in the
ext4 superblock
mb_max_to_scan
The maximum number of extents the multiblock allocator will search to
find the best extent.
mb_min_to_scan
The minimum number of extents the multiblock allocator will search to
find the best extent.
mb_order2_req
Tuning parameter which controls the minimum size for requests (as a
power of 2) where the buddy cache is used.
mb_stats
Controls whether the multiblock allocator should collect statistics,
which are shown during the unmount. 1 means to collect statistics, 0
means not to collect statistics.
mb_stream_req
Files which have fewer blocks than this tunable parameter will have
their blocks allocated out of a block group specific preallocation
pool, so that small files are packed closely together. Each large file
will have its blocks allocated out of its own unique preallocation
pool.
session_write_kbytes
This file is read-only and shows the number of kilobytes of data that
have been written to this filesystem since it was mounted.
reserved_clusters
This is RW file and contains number of reserved clusters in the file
system which will be used in the specific situations to avoid costly
zeroout, unexpected ENOSPC, or possible data loss. The default is 2% or
4096 clusters, whichever is smaller and this can be changed however it
can never exceed number of clusters in the file system. If there is not
enough space for the reserved space when mounting the file mount will
_not_ fail.
Ioctls
======
There is some Ext4 specific functionality which can be accessed by applications
through the system call interfaces. The list of all Ext4 specific ioctls are
shown in the table below.
Table of Ext4 specific ioctls
EXT4_IOC_GETFLAGS
Get additional attributes associated with inode. The ioctl argument is
an integer bitfield, with bit values described in ext4.h. This ioctl is
an alias for FS_IOC_GETFLAGS.
EXT4_IOC_SETFLAGS
Set additional attributes associated with inode. The ioctl argument is
an integer bitfield, with bit values described in ext4.h. This ioctl is
an alias for FS_IOC_SETFLAGS.
EXT4_IOC_GETVERSION, EXT4_IOC_GETVERSION_OLD
Get the inode i_generation number stored for each inode. The
i_generation number is normally changed only when new inode is created
and it is particularly useful for network filesystems. The '_OLD'
version of this ioctl is an alias for FS_IOC_GETVERSION.
EXT4_IOC_SETVERSION, EXT4_IOC_SETVERSION_OLD
Set the inode i_generation number stored for each inode. The '_OLD'
version of this ioctl is an alias for FS_IOC_SETVERSION.
EXT4_IOC_GROUP_EXTEND
This ioctl has the same purpose as the resize mount option. It allows
to resize filesystem to the end of the last existing block group,
further resize has to be done with resize2fs, either online, or
offline. The argument points to the unsigned logn number representing
the filesystem new block count.
EXT4_IOC_MOVE_EXT
Move the block extents from orig_fd (the one this ioctl is pointing to)
to the donor_fd (the one specified in move_extent structure passed as
an argument to this ioctl). Then, exchange inode metadata between
orig_fd and donor_fd. This is especially useful for online
defragmentation, because the allocator has the opportunity to allocate
moved blocks better, ideally into one contiguous extent.
EXT4_IOC_GROUP_ADD
Add a new group descriptor to an existing or new group descriptor
block. The new group descriptor is described by ext4_new_group_input
structure, which is passed as an argument to this ioctl. This is
especially useful in conjunction with EXT4_IOC_GROUP_EXTEND, which
allows online resize of the filesystem to the end of the last existing
block group. Those two ioctls combined is used in userspace online
resize tool (e.g. resize2fs).
EXT4_IOC_MIGRATE
This ioctl operates on the filesystem itself. It converts (migrates)
ext3 indirect block mapped inode to ext4 extent mapped inode by walking
through indirect block mapping of the original inode and converting
contiguous block ranges into ext4 extents of the temporary inode. Then,
inodes are swapped. This ioctl might help, when migrating from ext3 to
ext4 filesystem, however suggestion is to create fresh ext4 filesystem
and copy data from the backup. Note, that filesystem has to support
extents for this ioctl to work.
EXT4_IOC_ALLOC_DA_BLKS
Force all of the delay allocated blocks to be allocated to preserve
application-expected ext3 behaviour. Note that this will also start
triggering a write of the data blocks, but this behaviour may change in
the future as it is not necessary and has been done this way only for
sake of simplicity.
EXT4_IOC_RESIZE_FS
Resize the filesystem to a new size. The number of blocks of resized
filesystem is passed in via 64 bit integer argument. The kernel
allocates bitmaps and inode table, the userspace tool thus just passes
the new number of blocks.
EXT4_IOC_SWAP_BOOT
Swap i_blocks and associated attributes (like i_blocks, i_size,
i_flags, ...) from the specified inode with inode EXT4_BOOT_LOADER_INO
(#5). This is typically used to store a boot loader in a secure part of
the filesystem, where it can't be changed by a normal user by accident.
The data blocks of the previous boot loader will be associated with the
given inode.
References
==========
kernel source: <file:fs/ext4/>
<file:fs/jbd2/>
programs: http://e2fsprogs.sourceforge.net/
useful links: http://fedoraproject.org/wiki/ext3-devel
http://www.bullopensource.org/ext4/
http://ext4.wiki.kernel.org/index.php/Main_Page
http://fedoraproject.org/wiki/Features/Ext4

1
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@ -71,6 +71,7 @@ configure specific aspects of kernel behavior to your liking.
java
ras
bcache
ext4
pm/index
thunderbolt
LSM/index

4
Documentation/conf.py
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@ -383,6 +383,10 @@ latex_documents = [
'The kernel development community', 'manual'),
('filesystems/index', 'filesystems.tex', 'Linux Filesystems API',
'The kernel development community', 'manual'),
('admin-guide/ext4', 'ext4-admin-guide.tex', 'ext4 Administration Guide',
'ext4 Community', 'manual'),
('filesystems/ext4/index', 'ext4-data-structures.tex',
'ext4 Data Structures and Algorithms', 'ext4 Community', 'manual'),
('gpu/index', 'gpu.tex', 'Linux GPU Driver Developer\'s Guide',
'The kernel development community', 'manual'),
('input/index', 'linux-input.tex', 'The Linux input driver subsystem',

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@ -30,7 +30,7 @@ Extended attributes, when stored after the inode, have a header
``ext4_xattr_ibody_header`` that is 4 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -47,7 +47,7 @@ The beginning of an extended attribute block is in
``struct ext4_xattr_header``, which is 32 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -92,7 +92,7 @@ entries must be stored in sorted order. The sort order is
Attributes stored inside an inode do not need be stored in sorted order.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -157,7 +157,7 @@ attribute name index field is set, and matching string is removed from
the key name. Here is a map of name index values to key prefixes:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Name Index

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@ -28,7 +28,7 @@ of checksum. The checksum function is whatever the superblock describes
(crc32c as of October 2013) unless noted otherwise.
.. list-table::
:widths: 1 1 4
:widths: 20 8 50
:header-rows: 1
* - Metadata

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@ -34,7 +34,7 @@ is at most 263 bytes long, though on disk you'll need to reference
``dirent.rec_len`` to know for sure.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -66,7 +66,7 @@ tree traversal. This format is ``ext4_dir_entry_2``, which is at most
``dirent.rec_len`` to know for sure.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -99,7 +99,7 @@ tree traversal. This format is ``ext4_dir_entry_2``, which is at most
The directory file type is one of the following values:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -130,7 +130,7 @@ in the place where the name normally goes. The structure is
``struct ext4_dir_entry_tail``:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -212,7 +212,7 @@ The root of the htree is in ``struct dx_root``, which is the full length
of a data block:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -305,7 +305,7 @@ of a data block:
The directory hash is one of the following values:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -327,7 +327,7 @@ Interior nodes of an htree are recorded as ``struct dx_node``, which is
also the full length of a data block:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -375,7 +375,7 @@ The hash maps that exist in both ``struct dx_root`` and
long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -405,7 +405,7 @@ directory index (which will ensure that there's space for the checksum.
The dx\_tail structure is 8 bytes long and looks like this:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset

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@ -1,613 +0,0 @@
.. SPDX-License-Identifier: GPL-2.0
========================
General Information
========================
Ext4 is an advanced level of the ext3 filesystem which incorporates
scalability and reliability enhancements for supporting large filesystems
(64 bit) in keeping with increasing disk capacities and state-of-the-art
feature requirements.
Mailing list: linux-ext4@vger.kernel.org
Web site: http://ext4.wiki.kernel.org
Quick usage instructions
========================
Note: More extensive information for getting started with ext4 can be
found at the ext4 wiki site at the URL:
http://ext4.wiki.kernel.org/index.php/Ext4_Howto
- The latest version of e2fsprogs can be found at:
https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/
or
http://sourceforge.net/project/showfiles.php?group_id=2406
or grab the latest git repository from:
https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git
- Create a new filesystem using the ext4 filesystem type:
# mke2fs -t ext4 /dev/hda1
Or to configure an existing ext3 filesystem to support extents:
# tune2fs -O extents /dev/hda1
If the filesystem was created with 128 byte inodes, it can be
converted to use 256 byte for greater efficiency via:
# tune2fs -I 256 /dev/hda1
- Mounting:
# mount -t ext4 /dev/hda1 /wherever
- When comparing performance with other filesystems, it's always
important to try multiple workloads; very often a subtle change in a
workload parameter can completely change the ranking of which
filesystems do well compared to others. When comparing versus ext3,
note that ext4 enables write barriers by default, while ext3 does
not enable write barriers by default. So it is useful to use
explicitly specify whether barriers are enabled or not when via the
'-o barriers=[0|1]' mount option for both ext3 and ext4 filesystems
for a fair comparison. When tuning ext3 for best benchmark numbers,
it is often worthwhile to try changing the data journaling mode; '-o
data=writeback' can be faster for some workloads. (Note however that
running mounted with data=writeback can potentially leave stale data
exposed in recently written files in case of an unclean shutdown,
which could be a security exposure in some situations.) Configuring
the filesystem with a large journal can also be helpful for
metadata-intensive workloads.
Features
========
Currently Available
-------------------
* ability to use filesystems > 16TB (e2fsprogs support not available yet)
* extent format reduces metadata overhead (RAM, IO for access, transactions)
* extent format more robust in face of on-disk corruption due to magics,
* internal redundancy in tree
* improved file allocation (multi-block alloc)
* lift 32000 subdirectory limit imposed by i_links_count[1]
* nsec timestamps for mtime, atime, ctime, create time
* inode version field on disk (NFSv4, Lustre)
* reduced e2fsck time via uninit_bg feature
* journal checksumming for robustness, performance
* persistent file preallocation (e.g for streaming media, databases)
* ability to pack bitmaps and inode tables into larger virtual groups via the
flex_bg feature
* large file support
* inode allocation using large virtual block groups via flex_bg
* delayed allocation
* large block (up to pagesize) support
* efficient new ordered mode in JBD2 and ext4 (avoid using buffer head to force
the ordering)
[1] Filesystems with a block size of 1k may see a limit imposed by the
directory hash tree having a maximum depth of two.
Options
=======
When mounting an ext4 filesystem, the following option are accepted:
(*) == default
======================= =======================================================
Mount Option Description
======================= =======================================================
ro Mount filesystem read only. Note that ext4 will
replay the journal (and thus write to the
partition) even when mounted "read only". The
mount options "ro,noload" can be used to prevent
writes to the filesystem.
journal_checksum Enable checksumming of the journal transactions.
This will allow the recovery code in e2fsck and the
kernel to detect corruption in the kernel. It is a
compatible change and will be ignored by older kernels.
journal_async_commit Commit block can be written to disk without waiting
for descriptor blocks. If enabled older kernels cannot
mount the device. This will enable 'journal_checksum'
internally.
journal_path=path
journal_dev=devnum When the external journal device's major/minor numbers
have changed, these options allow the user to specify
the new journal location. The journal device is
identified through either its new major/minor numbers
encoded in devnum, or via a path to the device.
norecovery Don't load the journal on mounting. Note that
noload if the filesystem was not unmounted cleanly,
skipping the journal replay will lead to the
filesystem containing inconsistencies that can
lead to any number of problems.
data=journal All data are committed into the journal prior to being
written into the main file system. Enabling
this mode will disable delayed allocation and
O_DIRECT support.
data=ordered (*) All data are forced directly out to the main file
system prior to its metadata being committed to the
journal.
data=writeback Data ordering is not preserved, data may be written
into the main file system after its metadata has been
committed to the journal.
commit=nrsec (*) Ext4 can be told to sync all its data and metadata
every 'nrsec' seconds. The default value is 5 seconds.
This means that if you lose your power, you will lose
as much as the latest 5 seconds of work (your
filesystem will not be damaged though, thanks to the
journaling). This default value (or any low value)
will hurt performance, but it's good for data-safety.
Setting it to 0 will have the same effect as leaving
it at the default (5 seconds).
Setting it to very large values will improve
performance.
barrier=<0|1(*)> This enables/disables the use of write barriers in
barrier(*) the jbd code. barrier=0 disables, barrier=1 enables.
nobarrier This also requires an IO stack which can support
barriers, and if jbd gets an error on a barrier
write, it will disable again with a warning.
Write barriers enforce proper on-disk ordering
of journal commits, making volatile disk write caches
safe to use, at some performance penalty. If
your disks are battery-backed in one way or another,
disabling barriers may safely improve performance.
The mount options "barrier" and "nobarrier" can
also be used to enable or disable barriers, for
consistency with other ext4 mount options.
inode_readahead_blks=n This tuning parameter controls the maximum
number of inode table blocks that ext4's inode
table readahead algorithm will pre-read into
the buffer cache. The default value is 32 blocks.
nouser_xattr Disables Extended User Attributes. See the
attr(5) manual page for more information about
extended attributes.
noacl This option disables POSIX Access Control List
support. If ACL support is enabled in the kernel
configuration (CONFIG_EXT4_FS_POSIX_ACL), ACL is
enabled by default on mount. See the acl(5) manual
page for more information about acl.
bsddf (*) Make 'df' act like BSD.
minixdf Make 'df' act like Minix.
debug Extra debugging information is sent to syslog.
abort Simulate the effects of calling ext4_abort() for
debugging purposes. This is normally used while
remounting a filesystem which is already mounted.
errors=remount-ro Remount the filesystem read-only on an error.
errors=continue Keep going on a filesystem error.
errors=panic Panic and halt the machine if an error occurs.
(These mount options override the errors behavior
specified in the superblock, which can be configured
using tune2fs)
data_err=ignore(*) Just print an error message if an error occurs
in a file data buffer in ordered mode.
data_err=abort Abort the journal if an error occurs in a file
data buffer in ordered mode.
grpid New objects have the group ID of their parent.
bsdgroups
nogrpid (*) New objects have the group ID of their creator.
sysvgroups
resgid=n The group ID which may use the reserved blocks.
resuid=n The user ID which may use the reserved blocks.
sb=n Use alternate superblock at this location.
quota These options are ignored by the filesystem. They
noquota are used only by quota tools to recognize volumes
grpquota where quota should be turned on. See documentation
usrquota in the quota-tools package for more details
(http://sourceforge.net/projects/linuxquota).
jqfmt=<quota type> These options tell filesystem details about quota
usrjquota=<file> so that quota information can be properly updated
grpjquota=<file> during journal replay. They replace the above
quota options. See documentation in the quota-tools
package for more details
(http://sourceforge.net/projects/linuxquota).
stripe=n Number of filesystem blocks that mballoc will try
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data
disks * RAID chunk size in file system blocks.
delalloc (*) Defer block allocation until just before ext4
writes out the block(s) in question. This
allows ext4 to better allocation decisions
more efficiently.
nodelalloc Disable delayed allocation. Blocks are allocated
when the data is copied from userspace to the
page cache, either via the write(2) system call
or when an mmap'ed page which was previously
unallocated is written for the first time.
max_batch_time=usec Maximum amount of time ext4 should wait for
additional filesystem operations to be batch
together with a synchronous write operation.
Since a synchronous write operation is going to
force a commit and then a wait for the I/O
complete, it doesn't cost much, and can be a
huge throughput win, we wait for a small amount
of time to see if any other transactions can
piggyback on the synchronous write. The
algorithm used is designed to automatically tune
for the speed of the disk, by measuring the
amount of time (on average) that it takes to
finish committing a transaction. Call this time
the "commit time". If the time that the
transaction has been running is less than the
commit time, ext4 will try sleeping for the
commit time to see if other operations will join
the transaction. The commit time is capped by
the max_batch_time, which defaults to 15000us
(15ms). This optimization can be turned off
entirely by setting max_batch_time to 0.
min_batch_time=usec This parameter sets the commit time (as
described above) to be at least min_batch_time.
It defaults to zero microseconds. Increasing
this parameter may improve the throughput of
multi-threaded, synchronous workloads on very
fast disks, at the cost of increasing latency.
journal_ioprio=prio The I/O priority (from 0 to 7, where 0 is the
highest priority) which should be used for I/O
operations submitted by kjournald2 during a
commit operation. This defaults to 3, which is
a slightly higher priority than the default I/O
priority.
auto_da_alloc(*) Many broken applications don't use fsync() when
noauto_da_alloc replacing existing files via patterns such as
fd = open("foo.new")/write(fd,..)/close(fd)/
rename("foo.new", "foo"), or worse yet,
fd = open("foo", O_TRUNC)/write(fd,..)/close(fd).
If auto_da_alloc is enabled, ext4 will detect
the replace-via-rename and replace-via-truncate
patterns and force that any delayed allocation
blocks are allocated such that at the next
journal commit, in the default data=ordered
mode, the data blocks of the new file are forced
to disk before the rename() operation is
committed. This provides roughly the same level
of guarantees as ext3, and avoids the
"zero-length" problem that can happen when a
system crashes before the delayed allocation
blocks are forced to disk.
noinit_itable Do not initialize any uninitialized inode table
blocks in the background. This feature may be
used by installation CD's so that the install
process can complete as quickly as possible; the
inode table initialization process would then be
deferred until the next time the file system
is unmounted.
init_itable=n The lazy itable init code will wait n times the
number of milliseconds it took to zero out the
previous block group's inode table. This
minimizes the impact on the system performance
while file system's inode table is being initialized.
discard Controls whether ext4 should issue discard/TRIM
nodiscard(*) commands to the underlying block device when
blocks are freed. This is useful for SSD devices
and sparse/thinly-provisioned LUNs, but it is off
by default until sufficient testing has been done.
nouid32 Disables 32-bit UIDs and GIDs. This is for
interoperability with older kernels which only
store and expect 16-bit values.
block_validity(*) These options enable or disable the in-kernel
noblock_validity facility for tracking filesystem metadata blocks
within internal data structures. This allows multi-
block allocator and other routines to notice
bugs or corrupted allocation bitmaps which cause
blocks to be allocated which overlap with
filesystem metadata blocks.
dioread_lock Controls whether or not ext4 should use the DIO read
dioread_nolock locking. If the dioread_nolock option is specified
ext4 will allocate uninitialized extent before buffer
write and convert the extent to initialized after IO
completes. This approach allows ext4 code to avoid
using inode mutex, which improves scalability on high
speed storages. However this does not work with
data journaling and dioread_nolock option will be
ignored with kernel warning. Note that dioread_nolock
code path is only used for extent-based files.
Because of the restrictions this options comprises
it is off by default (e.g. dioread_lock).
max_dir_size_kb=n This limits the size of directories so that any
attempt to expand them beyond the specified
limit in kilobytes will cause an ENOSPC error.
This is useful in memory constrained
environments, where a very large directory can
cause severe performance problems or even
provoke the Out Of Memory killer. (For example,
if there is only 512mb memory available, a 176mb
directory may seriously cramp the system's style.)
i_version Enable 64-bit inode version support. This option is
off by default.
dax Use direct access (no page cache). See
Documentation/filesystems/dax.txt. Note that
this option is incompatible with data=journal.
======================= =======================================================
Data Mode
=========
There are 3 different data modes:
* writeback mode
In data=writeback mode, ext4 does not journal data at all. This mode provides
a similar level of journaling as that of XFS, JFS, and ReiserFS in its default
mode - metadata journaling. A crash+recovery can cause incorrect data to
appear in files which were written shortly before the crash. This mode will
typically provide the best ext4 performance.
* ordered mode
In data=ordered mode, ext4 only officially journals metadata, but it logically
groups metadata information related to data changes with the data blocks into
a single unit called a transaction. When it's time to write the new metadata
out to disk, the associated data blocks are written first. In general, this
mode performs slightly slower than writeback but significantly faster than
journal mode.
* journal mode
data=journal mode provides full data and metadata journaling. All new data is
written to the journal first, and then to its final location. In the event of
a crash, the journal can be replayed, bringing both data and metadata into a
consistent state. This mode is the slowest except when data needs to be read
from and written to disk at the same time where it outperforms all others
modes. Enabling this mode will disable delayed allocation and O_DIRECT
support.
/proc entries
=============
Information about mounted ext4 file systems can be found in
/proc/fs/ext4. Each mounted filesystem will have a directory in
/proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
/proc/fs/ext4/dm-0). The files in each per-device directory are shown
in table below.
Files in /proc/fs/ext4/<devname>
================ =======
File Content
================ =======
mb_groups details of multiblock allocator buddy cache of free blocks
================ =======
/sys entries
============
Information about mounted ext4 file systems can be found in
/sys/fs/ext4. Each mounted filesystem will have a directory in
/sys/fs/ext4 based on its device name (i.e., /sys/fs/ext4/hdc or
/sys/fs/ext4/dm-0). The files in each per-device directory are shown
in table below.
Files in /sys/fs/ext4/<devname>:
(see also Documentation/ABI/testing/sysfs-fs-ext4)
============================= =================================================
File Content
============================= =================================================
delayed_allocation_blocks This file is read-only and shows the number of
blocks that are dirty in the page cache, but
which do not have their location in the
filesystem allocated yet.
inode_goal Tuning parameter which (if non-zero) controls
the goal inode used by the inode allocator in
preference to all other allocation heuristics.
This is intended for debugging use only, and
should be 0 on production systems.
inode_readahead_blks Tuning parameter which controls the maximum
number of inode table blocks that ext4's inode
table readahead algorithm will pre-read into
the buffer cache
lifetime_write_kbytes This file is read-only and shows the number of
kilobytes of data that have been written to this
filesystem since it was created.
max_writeback_mb_bump The maximum number of megabytes the writeback
code will try to write out before move on to
another inode.
mb_group_prealloc The multiblock allocator will round up allocation
requests to a multiple of this tuning parameter if
the stripe size is not set in the ext4 superblock
mb_max_to_scan The maximum number of extents the multiblock
allocator will search to find the best extent
mb_min_to_scan The minimum number of extents the multiblock
allocator will search to find the best extent
mb_order2_req Tuning parameter which controls the minimum size
for requests (as a power of 2) where the buddy
cache is used
mb_stats Controls whether the multiblock allocator should
collect statistics, which are shown during the
unmount. 1 means to collect statistics, 0 means
not to collect statistics
mb_stream_req Files which have fewer blocks than this tunable
parameter will have their blocks allocated out
of a block group specific preallocation pool, so
that small files are packed closely together.
Each large file will have its blocks allocated
out of its own unique preallocation pool.
session_write_kbytes This file is read-only and shows the number of
kilobytes of data that have been written to this
filesystem since it was mounted.
reserved_clusters This is RW file and contains number of reserved
clusters in the file system which will be used
in the specific situations to avoid costly
zeroout, unexpected ENOSPC, or possible data
loss. The default is 2% or 4096 clusters,
whichever is smaller and this can be changed
however it can never exceed number of clusters
in the file system. If there is not enough space
for the reserved space when mounting the file
mount will _not_ fail.
============================= =================================================
Ioctls
======
There is some Ext4 specific functionality which can be accessed by applications
through the system call interfaces. The list of all Ext4 specific ioctls are
shown in the table below.
Table of Ext4 specific ioctls
============================= =================================================
Ioctl Description
============================= =================================================
EXT4_IOC_GETFLAGS Get additional attributes associated with inode.
The ioctl argument is an integer bitfield, with
bit values described in ext4.h. This ioctl is an
alias for FS_IOC_GETFLAGS.
EXT4_IOC_SETFLAGS Set additional attributes associated with inode.
The ioctl argument is an integer bitfield, with
bit values described in ext4.h. This ioctl is an
alias for FS_IOC_SETFLAGS.
EXT4_IOC_GETVERSION
EXT4_IOC_GETVERSION_OLD
Get the inode i_generation number stored for
each inode. The i_generation number is normally
changed only when new inode is created and it is
particularly useful for network filesystems. The
'_OLD' version of this ioctl is an alias for
FS_IOC_GETVERSION.
EXT4_IOC_SETVERSION
EXT4_IOC_SETVERSION_OLD
Set the inode i_generation number stored for
each inode. The '_OLD' version of this ioctl
is an alias for FS_IOC_SETVERSION.
EXT4_IOC_GROUP_EXTEND This ioctl has the same purpose as the resize
mount option. It allows to resize filesystem
to the end of the last existing block group,
further resize has to be done with resize2fs,
either online, or offline. The argument points
to the unsigned logn number representing the
filesystem new block count.
EXT4_IOC_MOVE_EXT Move the block extents from orig_fd (the one
this ioctl is pointing to) to the donor_fd (the
one specified in move_extent structure passed
as an argument to this ioctl). Then, exchange
inode metadata between orig_fd and donor_fd.
This is especially useful for online
defragmentation, because the allocator has the
opportunity to allocate moved blocks better,
ideally into one contiguous extent.
EXT4_IOC_GROUP_ADD Add a new group descriptor to an existing or
new group descriptor block. The new group
descriptor is described by ext4_new_group_input
structure, which is passed as an argument to
this ioctl. This is especially useful in
conjunction with EXT4_IOC_GROUP_EXTEND,
which allows online resize of the filesystem
to the end of the last existing block group.
Those two ioctls combined is used in userspace
online resize tool (e.g. resize2fs).
EXT4_IOC_MIGRATE This ioctl operates on the filesystem itself.
It converts (migrates) ext3 indirect block mapped
inode to ext4 extent mapped inode by walking
through indirect block mapping of the original
inode and converting contiguous block ranges
into ext4 extents of the temporary inode. Then,
inodes are swapped. This ioctl might help, when
migrating from ext3 to ext4 filesystem, however
suggestion is to create fresh ext4 filesystem
and copy data from the backup. Note, that
filesystem has to support extents for this ioctl
to work.
EXT4_IOC_ALLOC_DA_BLKS Force all of the delay allocated blocks to be
allocated to preserve application-expected ext3
behaviour. Note that this will also start
triggering a write of the data blocks, but this
behaviour may change in the future as it is
not necessary and has been done this way only
for sake of simplicity.
EXT4_IOC_RESIZE_FS Resize the filesystem to a new size. The number
of blocks of resized filesystem is passed in via
64 bit integer argument. The kernel allocates
bitmaps and inode table, the userspace tool thus
just passes the new number of blocks.
EXT4_IOC_SWAP_BOOT Swap i_blocks and associated attributes
(like i_blocks, i_size, i_flags, ...) from
the specified inode with inode
EXT4_BOOT_LOADER_INO (#5). This is typically
used to store a boot loader in a secure part of
the filesystem, where it can't be changed by a
normal user by accident.
The data blocks of the previous boot loader
will be associated with the given inode.
============================= =================================================
References
==========
kernel source: <file:fs/ext4/>
<file:fs/jbd2/>
programs: http://e2fsprogs.sourceforge.net/
useful links: http://fedoraproject.org/wiki/ext3-devel
http://www.bullopensource.org/ext4/
http://ext4.wiki.kernel.org/index.php/Main_Page
http://fedoraproject.org/wiki/Features/Ext4

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@ -43,7 +43,7 @@ entire bitmap.
The block group descriptor is laid out in ``struct ext4_group_desc``.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -157,7 +157,7 @@ The block group descriptor is laid out in ``struct ext4_group_desc``.
Block group flags can be any combination of the following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value

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@ -68,7 +68,7 @@ The extent tree header is recorded in ``struct ext4_extent_header``,
which is 12 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -104,7 +104,7 @@ Internal nodes of the extent tree, also known as index nodes, are
recorded as ``struct ext4_extent_idx``, and are 12 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -134,7 +134,7 @@ Leaf nodes of the extent tree are recorded as ``struct ext4_extent``,
and are also 12 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -174,7 +174,7 @@ including) the checksum itself.
``struct ext4_extent_tail`` is 4 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset

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@ -1,17 +1,14 @@
.. SPDX-License-Identifier: GPL-2.0
===============
ext4 Filesystem
===============
General usage and on-disk artifacts writen by ext4. More documentation may
be ported from the wiki as time permits. This should be considered the
canonical source of information as the details here have been reviewed by
the ext4 community.
===================================
ext4 Data Structures and Algorithms
===================================
.. toctree::
:maxdepth: 5
:maxdepth: 6
:numbered:
ext4
ondisk/index
about.rst
overview.rst
globals.rst
dynamic.rst

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19
Documentation/filesystems/ext4/ondisk/inodes.rst → Documentation/filesystems/ext4/inodes.rst
View File

@ -29,8 +29,9 @@ and the inode structure itself.
The inode table entry is laid out in ``struct ext4_inode``.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
:class: longtable
* - Offset
- Size
@ -176,7 +177,7 @@ The inode table entry is laid out in ``struct ext4_inode``.
The ``i_mode`` value is a combination of the following flags:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -227,7 +228,7 @@ The ``i_mode`` value is a combination of the following flags:
The ``i_flags`` field is a combination of these values:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -314,7 +315,7 @@ The ``osd1`` field has multiple meanings depending on the creator:
Linux:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -331,7 +332,7 @@ Linux:
Hurd:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -346,7 +347,7 @@ Hurd:
Masix:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -365,7 +366,7 @@ The ``osd2`` field has multiple meanings depending on the filesystem creator:
Linux:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -402,7 +403,7 @@ Linux:
Hurd:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -433,7 +434,7 @@ Hurd:
Masix:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset

32
Documentation/filesystems/ext4/ondisk/journal.rst → Documentation/filesystems/ext4/journal.rst
View File

@ -48,7 +48,7 @@ Layout
Generally speaking, the journal has this format:
.. list-table::
:widths: 1 1 78
:widths: 16 48 16
:header-rows: 1
* - Superblock
@ -76,7 +76,7 @@ The journal superblock will be in the next full block after the
superblock.
.. list-table::
:widths: 1 1 1 1 76
:widths: 12 12 12 32 12
:header-rows: 1
* - 1024 bytes of padding
@ -98,7 +98,7 @@ Every block in the journal starts with a common 12-byte header
``struct journal_header_s``:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -124,7 +124,7 @@ Every block in the journal starts with a common 12-byte header
The journal block type can be any one of:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -154,7 +154,7 @@ The journal superblock is recorded as ``struct journal_superblock_s``,
which is 1024 bytes long:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -264,7 +264,7 @@ which is 1024 bytes long:
The journal compat features are any combination of the following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -278,7 +278,7 @@ The journal compat features are any combination of the following:
The journal incompat features are any combination of the following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -306,7 +306,7 @@ Journal checksum type codes are one of the following. crc32 or crc32c are the
most likely choices.
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -330,7 +330,7 @@ described by a data structure, but here is the block structure anyway.
Descriptor blocks consume at least 36 bytes, but use a full block:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -355,7 +355,7 @@ defined as ``struct journal_block_tag3_s``, which looks like the
following. The size is 16 or 32 bytes.
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -400,7 +400,7 @@ following. The size is 16 or 32 bytes.
The journal tag flags are any combination of the following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -421,7 +421,7 @@ is defined as ``struct journal_block_tag_s``, which looks like the
following. The size is 8, 12, 24, or 28 bytes:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -471,7 +471,7 @@ JBD2\_FEATURE\_INCOMPAT\_CSUM\_V3 are set, the end of the block is a
``struct jbd2_journal_block_tail``, which looks like this:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -513,7 +513,7 @@ Revocation blocks are described in
length, but use a full block:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -543,7 +543,7 @@ JBD2\_FEATURE\_INCOMPAT\_CSUM\_V3 are set, the end of the revocation
block is a ``struct jbd2_journal_revoke_tail``, which has this format:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -567,7 +567,7 @@ The commit block is described by ``struct commit_header``, which is 32
bytes long (but uses a full block):
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset

2
Documentation/filesystems/ext4/ondisk/mmp.rst → Documentation/filesystems/ext4/mmp.rst
View File

@ -32,7 +32,7 @@ The checksum is calculated against the FS UUID and the MMP structure.
The MMP structure (``struct mmp_struct``) is as follows:
.. list-table::
:widths: 1 1 1 77
:widths: 8 12 20 40
:header-rows: 1
* - Offset

9
Documentation/filesystems/ext4/ondisk/index.rst
View File

@ -1,9 +0,0 @@
.. SPDX-License-Identifier: GPL-2.0
==============================
Data Structures and Algorithms
==============================
.. include:: about.rst
.. include:: overview.rst
.. include:: globals.rst
.. include:: dynamic.rst

0
Documentation/filesystems/ext4/ondisk/overview.rst → Documentation/filesystems/ext4/overview.rst
View File

2
Documentation/filesystems/ext4/ondisk/special_inodes.rst → Documentation/filesystems/ext4/special_inodes.rst
View File

@ -6,7 +6,7 @@ Special inodes
ext4 reserves some inode for special features, as follows:
.. list-table::
:widths: 1 79
:widths: 6 70
:header-rows: 1
* - inode Number

24
Documentation/filesystems/ext4/ondisk/super.rst → Documentation/filesystems/ext4/super.rst
View File

@ -19,7 +19,7 @@ The ext4 superblock is laid out as follows in
``struct ext4_super_block``:
.. list-table::
:widths: 1 1 1 77
:widths: 8 8 24 40
:header-rows: 1
* - Offset
@ -483,7 +483,7 @@ The ext4 superblock is laid out as follows in
The superblock state is some combination of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -500,7 +500,7 @@ The superblock state is some combination of the following:
The superblock error policy is one of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -517,7 +517,7 @@ The superblock error policy is one of the following:
The filesystem creator is one of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -538,7 +538,7 @@ The filesystem creator is one of the following:
The superblock revision is one of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -556,7 +556,7 @@ The superblock compatible features field is a combination of any of the
following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -595,7 +595,7 @@ The superblock incompatible features field is a combination of any of the
following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -647,7 +647,7 @@ The superblock read-only compatible features field is a combination of any of
the following:
.. list-table::
:widths: 1 79
:widths: 16 64
:header-rows: 1
* - Value
@ -702,7 +702,7 @@ the following:
The ``s_def_hash_version`` field is one of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -725,7 +725,7 @@ The ``s_def_hash_version`` field is one of the following:
The ``s_default_mount_opts`` field is any combination of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -767,7 +767,7 @@ The ``s_default_mount_opts`` field is any combination of the following:
The ``s_flags`` field is any combination of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value
@ -784,7 +784,7 @@ The ``s_flags`` field is any combination of the following:
The ``s_encrypt_algos`` list can contain any of the following:
.. list-table::
:widths: 1 79
:widths: 8 72
:header-rows: 1
* - Value

4
fs/ext4/acl.c
View File

@ -284,12 +284,16 @@ ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
default_acl, XATTR_CREATE);
posix_acl_release(default_acl);
} else {
inode->i_default_acl = NULL;
}
if (acl) {
if (!error)
error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
acl, XATTR_CREATE);
posix_acl_release(acl);
} else {
inode->i_acl = NULL;
}
return error;
}

17
fs/ext4/ext4.h
View File

@ -628,6 +628,7 @@ enum {
#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
#define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER 0x0010
#define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER 0x0020
#define EXT4_FREE_BLOCKS_RERESERVE_CLUSTER 0x0040
/*
* ioctl commands
@ -1030,6 +1031,9 @@ struct ext4_inode_info {
ext4_lblk_t i_da_metadata_calc_last_lblock;
int i_da_metadata_calc_len;
/* pending cluster reservations for bigalloc file systems */
struct ext4_pending_tree i_pending_tree;
/* on-disk additional length */
__u16 i_extra_isize;
@ -1401,7 +1405,8 @@ struct ext4_sb_info {
u32 s_min_batch_time;
struct block_device *journal_bdev;
#ifdef CONFIG_QUOTA
char *s_qf_names[EXT4_MAXQUOTAS]; /* Names of quota files with journalled quota */
/* Names of quota files with journalled quota */
char __rcu *s_qf_names[EXT4_MAXQUOTAS];
int s_jquota_fmt; /* Format of quota to use */
#endif
unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
@ -2483,10 +2488,11 @@ extern int ext4_writepage_trans_blocks(struct inode *);
extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
loff_t lstart, loff_t lend);
extern int ext4_page_mkwrite(struct vm_fault *vmf);
extern int ext4_filemap_fault(struct vm_fault *vmf);
extern vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf);
extern vm_fault_t ext4_filemap_fault(struct vm_fault *vmf);
extern qsize_t *ext4_get_reserved_space(struct inode *inode);
extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
extern void ext4_da_release_space(struct inode *inode, int to_free);
extern void ext4_da_update_reserve_space(struct inode *inode,
int used, int quota_claim);
extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
@ -3142,10 +3148,6 @@ extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
int flags);
extern void ext4_ext_drop_refs(struct ext4_ext_path *);
extern int ext4_ext_check_inode(struct inode *inode);
extern int ext4_find_delalloc_range(struct inode *inode,
ext4_lblk_t lblk_start,
ext4_lblk_t lblk_end);
extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len);
@ -3156,6 +3158,7 @@ extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
struct inode *inode2, ext4_lblk_t lblk1,
ext4_lblk_t lblk2, ext4_lblk_t count,
int mark_unwritten,int *err);
extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu);
/* move_extent.c */
extern void ext4_double_down_write_data_sem(struct inode *first,

13
fs/ext4/ext4_extents.h
View File

@ -119,6 +119,19 @@ struct ext4_ext_path {
struct buffer_head *p_bh;
};
/*
* Used to record a portion of a cluster found at the beginning or end
* of an extent while traversing the extent tree during space removal.
* A partial cluster may be removed if it does not contain blocks shared
* with extents that aren't being deleted (tofree state). Otherwise,
* it cannot be removed (nofree state).
*/
struct partial_cluster {
ext4_fsblk_t pclu; /* physical cluster number */
ext4_lblk_t lblk; /* logical block number within logical cluster */
enum {initial, tofree, nofree} state;
};
/*
* structure for external API
*/

597
fs/ext4/extents.c
View File

@ -2351,8 +2351,8 @@ ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
{
struct extent_status es;
ext4_es_find_delayed_extent_range(inode, hole_start,
hole_start + hole_len - 1, &es);
ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
hole_start + hole_len - 1, &es);
if (es.es_len) {
/* There's delayed extent containing lblock? */
if (es.es_lblk <= hole_start)
@ -2490,106 +2490,157 @@ static inline int get_default_free_blocks_flags(struct inode *inode)
return 0;
}
/*
* ext4_rereserve_cluster - increment the reserved cluster count when
* freeing a cluster with a pending reservation
*
* @inode - file containing the cluster
* @lblk - logical block in cluster to be reserved
*
* Increments the reserved cluster count and adjusts quota in a bigalloc
* file system when freeing a partial cluster containing at least one
* delayed and unwritten block. A partial cluster meeting that
* requirement will have a pending reservation. If so, the
* RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
* defer reserved and allocated space accounting to a subsequent call
* to this function.
*/
static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
spin_lock(&ei->i_block_reservation_lock);
ei->i_reserved_data_blocks++;
percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
spin_unlock(&ei->i_block_reservation_lock);
percpu_counter_add(&sbi->s_freeclusters_counter, 1);
ext4_remove_pending(inode, lblk);
}
static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
struct ext4_extent *ex,
long long *partial_cluster,
struct partial_cluster *partial,
ext4_lblk_t from, ext4_lblk_t to)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
unsigned short ee_len = ext4_ext_get_actual_len(ex);
ext4_fsblk_t pblk;
int flags = get_default_free_blocks_flags(inode);
ext4_fsblk_t last_pblk, pblk;
ext4_lblk_t num;
int flags;
/* only extent tail removal is allowed */
if (from < le32_to_cpu(ex->ee_block) ||
to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
ext4_error(sbi->s_sb,
"strange request: removal(2) %u-%u from %u:%u",
from, to, le32_to_cpu(ex->ee_block), ee_len);
return 0;
}
#ifdef EXTENTS_STATS
spin_lock(&sbi->s_ext_stats_lock);
sbi->s_ext_blocks += ee_len;
sbi->s_ext_extents++;
if (ee_len < sbi->s_ext_min)
sbi->s_ext_min = ee_len;
if (ee_len > sbi->s_ext_max)
sbi->s_ext_max = ee_len;
if (ext_depth(inode) > sbi->s_depth_max)
sbi->s_depth_max = ext_depth(inode);
spin_unlock(&sbi->s_ext_stats_lock);
#endif
trace_ext4_remove_blocks(inode, ex, from, to, partial);
/*
* if we have a partial cluster, and it's different from the
* cluster of the last block in the extent, we free it
*/
last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
if (partial->state != initial &&
partial->pclu != EXT4_B2C(sbi, last_pblk)) {
if (partial->state == tofree) {
flags = get_default_free_blocks_flags(inode);
if (ext4_is_pending(inode, partial->lblk))
flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, partial->pclu),
sbi->s_cluster_ratio, flags);
if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
ext4_rereserve_cluster(inode, partial->lblk);
}
partial->state = initial;
}
num = le32_to_cpu(ex->ee_block) + ee_len - from;
pblk = ext4_ext_pblock(ex) + ee_len - num;
/*
* We free the partial cluster at the end of the extent (if any),
* unless the cluster is used by another extent (partial_cluster
* state is nofree). If a partial cluster exists here, it must be
* shared with the last block in the extent.
*/
flags = get_default_free_blocks_flags(inode);
/* partial, left end cluster aligned, right end unaligned */
if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
(EXT4_LBLK_CMASK(sbi, to) >= from) &&
(partial->state != nofree)) {
if (ext4_is_pending(inode, to))
flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
ext4_free_blocks(handle, inode, NULL,
EXT4_PBLK_CMASK(sbi, last_pblk),
sbi->s_cluster_ratio, flags);
if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
ext4_rereserve_cluster(inode, to);
partial->state = initial;
flags = get_default_free_blocks_flags(inode);
}
flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
/*
* For bigalloc file systems, we never free a partial cluster
* at the beginning of the extent. Instead, we make a note
* that we tried freeing the cluster, and check to see if we
* at the beginning of the extent. Instead, we check to see if we
* need to free it on a subsequent call to ext4_remove_blocks,
* or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
*/
flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
/* reset the partial cluster if we've freed past it */
if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
partial->state = initial;
trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
/*
* If we have a partial cluster, and it's different from the
* cluster of the last block, we need to explicitly free the
* partial cluster here.
* If we've freed the entire extent but the beginning is not left
* cluster aligned and is not marked as ineligible for freeing we
* record the partial cluster at the beginning of the extent. It
* wasn't freed by the preceding ext4_free_blocks() call, and we
* need to look farther to the left to determine if it's to be freed
* (not shared with another extent). Else, reset the partial
* cluster - we're either done freeing or the beginning of the
* extent is left cluster aligned.
*/
pblk = ext4_ext_pblock(ex) + ee_len - 1;
if (*partial_cluster > 0 &&
*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, *partial_cluster),
sbi->s_cluster_ratio, flags);
*partial_cluster = 0;
}
#ifdef EXTENTS_STATS
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
spin_lock(&sbi->s_ext_stats_lock);
sbi->s_ext_blocks += ee_len;
sbi->s_ext_extents++;
if (ee_len < sbi->s_ext_min)
sbi->s_ext_min = ee_len;
if (ee_len > sbi->s_ext_max)
sbi->s_ext_max = ee_len;
if (ext_depth(inode) > sbi->s_depth_max)
sbi->s_depth_max = ext_depth(inode);
spin_unlock(&sbi->s_ext_stats_lock);
}
#endif
if (from >= le32_to_cpu(ex->ee_block)
&& to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
/* tail removal */
ext4_lblk_t num;
long long first_cluster;
num = le32_to_cpu(ex->ee_block) + ee_len - from;
pblk = ext4_ext_pblock(ex) + ee_len - num;
/*
* Usually we want to free partial cluster at the end of the
* extent, except for the situation when the cluster is still
* used by any other extent (partial_cluster is negative).
*/
if (*partial_cluster < 0 &&
*partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
ext_debug("free last %u blocks starting %llu partial %lld\n",
num, pblk, *partial_cluster);
ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
/*
* If the block range to be freed didn't start at the
* beginning of a cluster, and we removed the entire
* extent and the cluster is not used by any other extent,
* save the partial cluster here, since we might need to
* delete if we determine that the truncate or punch hole
* operation has removed all of the blocks in the cluster.
* If that cluster is used by another extent, preserve its
* negative value so it isn't freed later on.
*
* If the whole extent wasn't freed, we've reached the
* start of the truncated/punched region and have finished
* removing blocks. If there's a partial cluster here it's
* shared with the remainder of the extent and is no longer
* a candidate for removal.
*/
if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
first_cluster = (long long) EXT4_B2C(sbi, pblk);
if (first_cluster != -*partial_cluster)
*partial_cluster = first_cluster;
} else {
*partial_cluster = 0;
if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
if (partial->state == initial) {
partial->pclu = EXT4_B2C(sbi, pblk);
partial->lblk = from;
partial->state = tofree;
}
} else
ext4_error(sbi->s_sb, "strange request: removal(2) "
"%u-%u from %u:%u",
from, to, le32_to_cpu(ex->ee_block), ee_len);
} else {
partial->state = initial;
}
return 0;
}
/*
* ext4_ext_rm_leaf() Removes the extents associated with the
* blocks appearing between "start" and "end". Both "start"
@ -2608,7 +2659,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
static int
ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path,
long long *partial_cluster,
struct partial_cluster *partial,
ext4_lblk_t start, ext4_lblk_t end)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@ -2640,7 +2691,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
ex_ee_block = le32_to_cpu(ex->ee_block);
ex_ee_len = ext4_ext_get_actual_len(ex);
trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
trace_ext4_ext_rm_leaf(inode, start, ex, partial);
while (ex >= EXT_FIRST_EXTENT(eh) &&
ex_ee_block + ex_ee_len > start) {
@ -2671,8 +2722,8 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
*/
if (sbi->s_cluster_ratio > 1) {
pblk = ext4_ext_pblock(ex);
*partial_cluster =
-(long long) EXT4_B2C(sbi, pblk);
partial->pclu = EXT4_B2C(sbi, pblk);
partial->state = nofree;
}
ex--;
ex_ee_block = le32_to_cpu(ex->ee_block);
@ -2714,8 +2765,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
if (err)
goto out;
err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
a, b);
err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
if (err)
goto out;
@ -2769,18 +2819,23 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
* If there's a partial cluster and at least one extent remains in
* the leaf, free the partial cluster if it isn't shared with the
* current extent. If it is shared with the current extent
* we zero partial_cluster because we've reached the start of the
* we reset the partial cluster because we've reached the start of the
* truncated/punched region and we're done removing blocks.
*/
if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
if (partial->pclu != EXT4_B2C(sbi, pblk)) {
int flags = get_default_free_blocks_flags(inode);
if (ext4_is_pending(inode, partial->lblk))
flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, *partial_cluster),
sbi->s_cluster_ratio,
get_default_free_blocks_flags(inode));
EXT4_C2B(sbi, partial->pclu),
sbi->s_cluster_ratio, flags);
if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
ext4_rereserve_cluster(inode, partial->lblk);
}
*partial_cluster = 0;
partial->state = initial;
}
/* if this leaf is free, then we should
@ -2819,10 +2874,14 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int depth = ext_depth(inode);
struct ext4_ext_path *path = NULL;
long long partial_cluster = 0;
struct partial_cluster partial;
handle_t *handle;
int i = 0, err = 0;
partial.pclu = 0;
partial.lblk = 0;
partial.state = initial;
ext_debug("truncate since %u to %u\n", start, end);
/* probably first extent we're gonna free will be last in block */
@ -2882,8 +2941,8 @@ again:
*/
if (sbi->s_cluster_ratio > 1) {
pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
partial_cluster =
-(long long) EXT4_B2C(sbi, pblk);
partial.pclu = EXT4_B2C(sbi, pblk);
partial.state = nofree;
}
/*
@ -2911,9 +2970,10 @@ again:
&ex);
if (err)
goto out;
if (pblk)
partial_cluster =
-(long long) EXT4_B2C(sbi, pblk);
if (pblk) {
partial.pclu = EXT4_B2C(sbi, pblk);
partial.state = nofree;
}
}
}
/*
@ -2948,8 +3008,7 @@ again:
if (i == depth) {
/* this is leaf block */
err = ext4_ext_rm_leaf(handle, inode, path,
&partial_cluster, start,
end);
&partial, start, end);
/* root level has p_bh == NULL, brelse() eats this */
brelse(path[i].p_bh);
path[i].p_bh = NULL;
@ -3021,21 +3080,24 @@ again:
}
}
trace_ext4_ext_remove_space_done(inode, start, end, depth,
partial_cluster, path->p_hdr->eh_entries);
trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
path->p_hdr->eh_entries);
/*
* If we still have something in the partial cluster and we have removed
* even the first extent, then we should free the blocks in the partial
* cluster as well. (This code will only run when there are no leaves
* to the immediate left of the truncated/punched region.)
* if there's a partial cluster and we have removed the first extent
* in the file, then we also free the partial cluster, if any
*/
if (partial_cluster > 0 && err == 0) {
/* don't zero partial_cluster since it's not used afterwards */
if (partial.state == tofree && err == 0) {
int flags = get_default_free_blocks_flags(inode);
if (ext4_is_pending(inode, partial.lblk))
flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, partial_cluster),
sbi->s_cluster_ratio,
get_default_free_blocks_flags(inode));
EXT4_C2B(sbi, partial.pclu),
sbi->s_cluster_ratio, flags);
if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
ext4_rereserve_cluster(inode, partial.lblk);
partial.state = initial;
}
/* TODO: flexible tree reduction should be here */
@ -3819,114 +3881,6 @@ out:
return ext4_mark_inode_dirty(handle, inode);
}
/**
* ext4_find_delalloc_range: find delayed allocated block in the given range.
*
* Return 1 if there is a delalloc block in the range, otherwise 0.
*/
int ext4_find_delalloc_range(struct inode *inode,
ext4_lblk_t lblk_start,
ext4_lblk_t lblk_end)
{
struct extent_status es;
ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
if (es.es_len == 0)
return 0; /* there is no delay extent in this tree */
else if (es.es_lblk <= lblk_start &&
lblk_start < es.es_lblk + es.es_len)
return 1;
else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
return 1;
else
return 0;
}
int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t lblk_start, lblk_end;
lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
}
/**
* Determines how many complete clusters (out of those specified by the 'map')
* are under delalloc and were reserved quota for.
* This function is called when we are writing out the blocks that were
* originally written with their allocation delayed, but then the space was
* allocated using fallocate() before the delayed allocation could be resolved.
* The cases to look for are:
* ('=' indicated delayed allocated blocks
* '-' indicates non-delayed allocated blocks)
* (a) partial clusters towards beginning and/or end outside of allocated range
* are not delalloc'ed.
* Ex:
* |----c---=|====c====|====c====|===-c----|
* |++++++ allocated ++++++|
* ==> 4 complete clusters in above example
*
* (b) partial cluster (outside of allocated range) towards either end is
* marked for delayed allocation. In this case, we will exclude that
* cluster.
* Ex:
* |----====c========|========c========|
* |++++++ allocated ++++++|
* ==> 1 complete clusters in above example
*
* Ex:
* |================c================|
* |++++++ allocated ++++++|
* ==> 0 complete clusters in above example
*
* The ext4_da_update_reserve_space will be called only if we
* determine here that there were some "entire" clusters that span
* this 'allocated' range.
* In the non-bigalloc case, this function will just end up returning num_blks
* without ever calling ext4_find_delalloc_range.
*/
static unsigned int
get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
unsigned int num_blks)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
ext4_lblk_t lblk_from, lblk_to, c_offset;
unsigned int allocated_clusters = 0;
alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
/* max possible clusters for this allocation */
allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
/* Check towards left side */
c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
if (c_offset) {
lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
lblk_to = lblk_from + c_offset - 1;
if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
allocated_clusters--;
}
/* Now check towards right. */
c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
if (allocated_clusters && c_offset) {
lblk_from = lblk_start + num_blks;
lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
allocated_clusters--;
}
return allocated_clusters;
}
static int
convert_initialized_extent(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map,
@ -4108,23 +4062,6 @@ out:
}
map->m_len = allocated;
/*
* If we have done fallocate with the offset that is already
* delayed allocated, we would have block reservation
* and quota reservation done in the delayed write path.
* But fallocate would have already updated quota and block
* count for this offset. So cancel these reservation
*/
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
unsigned int reserved_clusters;
reserved_clusters = get_reserved_cluster_alloc(inode,
map->m_lblk, map->m_len);
if (reserved_clusters)
ext4_da_update_reserve_space(inode,
reserved_clusters,
0);
}
map_out:
map->m_flags |= EXT4_MAP_MAPPED;
if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
@ -4513,77 +4450,39 @@ got_allocated_blocks:
map->m_flags |= EXT4_MAP_NEW;
/*
* Update reserved blocks/metadata blocks after successful
* block allocation which had been deferred till now.
* Reduce the reserved cluster count to reflect successful deferred
* allocation of delayed allocated clusters or direct allocation of
* clusters discovered to be delayed allocated. Once allocated, a
* cluster is not included in the reserved count.
*/
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
unsigned int reserved_clusters;
/*
* Check how many clusters we had reserved this allocated range
*/
reserved_clusters = get_reserved_cluster_alloc(inode,
map->m_lblk, allocated);
if (!map_from_cluster) {
BUG_ON(allocated_clusters < reserved_clusters);
if (reserved_clusters < allocated_clusters) {
struct ext4_inode_info *ei = EXT4_I(inode);
int reservation = allocated_clusters -
reserved_clusters;
/*
* It seems we claimed few clusters outside of
* the range of this allocation. We should give
* it back to the reservation pool. This can
* happen in the following case:
*
* * Suppose s_cluster_ratio is 4 (i.e., each
* cluster has 4 blocks. Thus, the clusters
* are [0-3],[4-7],[8-11]...
* * First comes delayed allocation write for
* logical blocks 10 & 11. Since there were no
* previous delayed allocated blocks in the
* range [8-11], we would reserve 1 cluster
* for this write.
* * Next comes write for logical blocks 3 to 8.
* In this case, we will reserve 2 clusters
* (for [0-3] and [4-7]; and not for [8-11] as
* that range has a delayed allocated blocks.
* Thus total reserved clusters now becomes 3.
* * Now, during the delayed allocation writeout
* time, we will first write blocks [3-8] and
* allocate 3 clusters for writing these
* blocks. Also, we would claim all these
* three clusters above.
* * Now when we come here to writeout the
* blocks [10-11], we would expect to claim
* the reservation of 1 cluster we had made
* (and we would claim it since there are no
* more delayed allocated blocks in the range
* [8-11]. But our reserved cluster count had
* already gone to 0.
*
* Thus, at the step 4 above when we determine
* that there are still some unwritten delayed
* allocated blocks outside of our current
* block range, we should increment the
* reserved clusters count so that when the
* remaining blocks finally gets written, we
* could claim them.
*/
dquot_reserve_block(inode,
EXT4_C2B(sbi, reservation));
spin_lock(&ei->i_block_reservation_lock);
ei->i_reserved_data_blocks += reservation;
spin_unlock(&ei->i_block_reservation_lock);
}
if (test_opt(inode->i_sb, DELALLOC) && !map_from_cluster) {
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
/*
* We will claim quota for all newly allocated blocks.
* We're updating the reserved space *after* the
* correction above so we do not accidentally free
* all the metadata reservation because we might
* actually need it later on.
* When allocating delayed allocated clusters, simply
* reduce the reserved cluster count and claim quota
*/
ext4_da_update_reserve_space(inode, allocated_clusters,
1);
} else {
ext4_lblk_t lblk, len;
unsigned int n;
/*
* When allocating non-delayed allocated clusters
* (from fallocate, filemap, DIO, or clusters
* allocated when delalloc has been disabled by
* ext4_nonda_switch), reduce the reserved cluster
* count by the number of allocated clusters that
* have previously been delayed allocated. Quota
* has been claimed by ext4_mb_new_blocks() above,
* so release the quota reservations made for any
* previously delayed allocated clusters.
*/
lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
len = allocated_clusters << sbi->s_cluster_bits;
n = ext4_es_delayed_clu(inode, lblk, len);
if (n > 0)
ext4_da_update_reserve_space(inode, (int) n, 0);
}
}
@ -5075,8 +4974,10 @@ static int ext4_find_delayed_extent(struct inode *inode,
ext4_lblk_t block, next_del;
if (newes->es_pblk == 0) {
ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
newes->es_lblk + newes->es_len - 1, &es);
ext4_es_find_extent_range(inode, &ext4_es_is_delayed,
newes->es_lblk,
newes->es_lblk + newes->es_len - 1,
&es);
/*
* No extent in extent-tree contains block @newes->es_pblk,
@ -5097,7 +4998,8 @@ static int ext4_find_delayed_extent(struct inode *inode,
}
block = newes->es_lblk + newes->es_len;
ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
ext4_es_find_extent_range(inode, &ext4_es_is_delayed, block,
EXT_MAX_BLOCKS, &es);
if (es.es_len == 0)
next_del = EXT_MAX_BLOCKS;
else
@ -5958,3 +5860,82 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
}
return replaced_count;
}
/*
* ext4_clu_mapped - determine whether any block in a logical cluster has
* been mapped to a physical cluster
*
* @inode - file containing the logical cluster
* @lclu - logical cluster of interest
*
* Returns 1 if any block in the logical cluster is mapped, signifying
* that a physical cluster has been allocated for it. Otherwise,
* returns 0. Can also return negative error codes. Derived from
* ext4_ext_map_blocks().
*/
int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_ext_path *path;
int depth, mapped = 0, err = 0;
struct ext4_extent *extent;
ext4_lblk_t first_lblk, first_lclu, last_lclu;
/* search for the extent closest to the first block in the cluster */
path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
if (IS_ERR(path)) {
err = PTR_ERR(path);
path = NULL;
goto out;
}
depth = ext_depth(inode);
/*
* A consistent leaf must not be empty. This situation is possible,
* though, _during_ tree modification, and it's why an assert can't
* be put in ext4_find_extent().
*/
if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
EXT4_ERROR_INODE(inode,
"bad extent address - lblock: %lu, depth: %d, pblock: %lld",
(unsigned long) EXT4_C2B(sbi, lclu),
depth, path[depth].p_block);
err = -EFSCORRUPTED;
goto out;
}
extent = path[depth].p_ext;
/* can't be mapped if the extent tree is empty */
if (extent == NULL)
goto out;
first_lblk = le32_to_cpu(extent->ee_block);
first_lclu = EXT4_B2C(sbi, first_lblk);
/*
* Three possible outcomes at this point - found extent spanning
* the target cluster, to the left of the target cluster, or to the
* right of the target cluster. The first two cases are handled here.
* The last case indicates the target cluster is not mapped.
*/
if (lclu >= first_lclu) {
last_lclu = EXT4_B2C(sbi, first_lblk +
ext4_ext_get_actual_len(extent) - 1);
if (lclu <= last_lclu) {
mapped = 1;
} else {
first_lblk = ext4_ext_next_allocated_block(path);
first_lclu = EXT4_B2C(sbi, first_lblk);
if (lclu == first_lclu)
mapped = 1;
}
}
out:
ext4_ext_drop_refs(path);
kfree(path);
return err ? err : mapped;
}

654
fs/ext4/extents_status.c
View File

@ -142,6 +142,7 @@
*/
static struct kmem_cache *ext4_es_cachep;
static struct kmem_cache *ext4_pending_cachep;
static int __es_insert_extent(struct inode *inode, struct extent_status *newes);
static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
@ -149,6 +150,8 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
struct ext4_inode_info *locked_ei);
static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
int __init ext4_init_es(void)
{
@ -233,30 +236,38 @@ static struct extent_status *__es_tree_search(struct rb_root *root,
}
/*
* ext4_es_find_delayed_extent_range: find the 1st delayed extent covering
* @es->lblk if it exists, otherwise, the next extent after @es->lblk.
* ext4_es_find_extent_range - find extent with specified status within block
* range or next extent following block range in
* extents status tree
*
* @inode: the inode which owns delayed extents
* @lblk: the offset where we start to search
* @end: the offset where we stop to search
* @es: delayed extent that we found
* @inode - file containing the range
* @matching_fn - pointer to function that matches extents with desired status
* @lblk - logical block defining start of range
* @end - logical block defining end of range
* @es - extent found, if any
*
* Find the first extent within the block range specified by @lblk and @end
* in the extents status tree that satisfies @matching_fn. If a match
* is found, it's returned in @es. If not, and a matching extent is found
* beyond the block range, it's returned in @es. If no match is found, an
* extent is returned in @es whose es_lblk, es_len, and es_pblk components
* are 0.
*/
void ext4_es_find_delayed_extent_range(struct inode *inode,
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es)
static void __es_find_extent_range(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es)
{
struct ext4_es_tree *tree = NULL;
struct extent_status *es1 = NULL;
struct rb_node *node;
BUG_ON(es == NULL);
BUG_ON(end < lblk);
trace_ext4_es_find_delayed_extent_range_enter(inode, lblk);
WARN_ON(es == NULL);
WARN_ON(end < lblk);
read_lock(&EXT4_I(inode)->i_es_lock);
tree = &EXT4_I(inode)->i_es_tree;
/* find extent in cache firstly */
/* see if the extent has been cached */
es->es_lblk = es->es_len = es->es_pblk = 0;
if (tree->cache_es) {
es1 = tree->cache_es;
@ -271,28 +282,133 @@ void ext4_es_find_delayed_extent_range(struct inode *inode,
es1 = __es_tree_search(&tree->root, lblk);
out:
if (es1 && !ext4_es_is_delayed(es1)) {
if (es1 && !matching_fn(es1)) {
while ((node = rb_next(&es1->rb_node)) != NULL) {
es1 = rb_entry(node, struct extent_status, rb_node);
if (es1->es_lblk > end) {
es1 = NULL;
break;
}
if (ext4_es_is_delayed(es1))
if (matching_fn(es1))
break;
}
}
if (es1 && ext4_es_is_delayed(es1)) {
if (es1 && matching_fn(es1)) {
tree->cache_es = es1;
es->es_lblk = es1->es_lblk;
es->es_len = es1->es_len;
es->es_pblk = es1->es_pblk;
}
}
/*
* Locking for __es_find_extent_range() for external use
*/
void ext4_es_find_extent_range(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es)
{
trace_ext4_es_find_extent_range_enter(inode, lblk);
read_lock(&EXT4_I(inode)->i_es_lock);
__es_find_extent_range(inode, matching_fn, lblk, end, es);
read_unlock(&EXT4_I(inode)->i_es_lock);
trace_ext4_es_find_delayed_extent_range_exit(inode, es);
trace_ext4_es_find_extent_range_exit(inode, es);
}
/*
* __es_scan_range - search block range for block with specified status
* in extents status tree
*
* @inode - file containing the range
* @matching_fn - pointer to function that matches extents with desired status
* @lblk - logical block defining start of range
* @end - logical block defining end of range
*
* Returns true if at least one block in the specified block range satisfies
* the criterion specified by @matching_fn, and false if not. If at least
* one extent has the specified status, then there is at least one block
* in the cluster with that status. Should only be called by code that has
* taken i_es_lock.
*/
static bool __es_scan_range(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t start, ext4_lblk_t end)
{
struct extent_status es;
__es_find_extent_range(inode, matching_fn, start, end, &es);
if (es.es_len == 0)
return false; /* no matching extent in the tree */
else if (es.es_lblk <= start &&
start < es.es_lblk + es.es_len)
return true;
else if (start <= es.es_lblk && es.es_lblk <= end)
return true;
else
return false;
}
/*
* Locking for __es_scan_range() for external use
*/
bool ext4_es_scan_range(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk, ext4_lblk_t end)
{
bool ret;
read_lock(&EXT4_I(inode)->i_es_lock);
ret = __es_scan_range(inode, matching_fn, lblk, end);
read_unlock(&EXT4_I(inode)->i_es_lock);
return ret;
}
/*
* __es_scan_clu - search cluster for block with specified status in
* extents status tree
*
* @inode - file containing the cluster
* @matching_fn - pointer to function that matches extents with desired status
* @lblk - logical block in cluster to be searched
*
* Returns true if at least one extent in the cluster containing @lblk
* satisfies the criterion specified by @matching_fn, and false if not. If at
* least one extent has the specified status, then there is at least one block
* in the cluster with that status. Should only be called by code that has
* taken i_es_lock.
*/
static bool __es_scan_clu(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t lblk_start, lblk_end;
lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
return __es_scan_range(inode, matching_fn, lblk_start, lblk_end);
}
/*
* Locking for __es_scan_clu() for external use
*/
bool ext4_es_scan_clu(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk)
{
bool ret;
read_lock(&EXT4_I(inode)->i_es_lock);
ret = __es_scan_clu(inode, matching_fn, lblk);
read_unlock(&EXT4_I(inode)->i_es_lock);
return ret;
}
static void ext4_es_list_add(struct inode *inode)
@ -694,6 +810,7 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status newes;
ext4_lblk_t end = lblk + len - 1;
int err = 0;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
es_debug("add [%u/%u) %llu %x to extent status tree of inode %lu\n",
lblk, len, pblk, status, inode->i_ino);
@ -730,6 +847,11 @@ retry:
if (err == -ENOMEM && !ext4_es_is_delayed(&newes))
err = 0;
if (sbi->s_cluster_ratio > 1 && test_opt(inode->i_sb, DELALLOC) &&
(status & EXTENT_STATUS_WRITTEN ||
status & EXTENT_STATUS_UNWRITTEN))
__revise_pending(inode, lblk, len);
error:
write_unlock(&EXT4_I(inode)->i_es_lock);
@ -1252,3 +1374,499 @@ static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan)
ei->i_es_tree.cache_es = NULL;
return nr_shrunk;
}
#ifdef ES_DEBUG__
static void ext4_print_pending_tree(struct inode *inode)
{
struct ext4_pending_tree *tree;
struct rb_node *node;
struct pending_reservation *pr;
printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino);
tree = &EXT4_I(inode)->i_pending_tree;
node = rb_first(&tree->root);
while (node) {
pr = rb_entry(node, struct pending_reservation, rb_node);
printk(KERN_DEBUG " %u", pr->lclu);
node = rb_next(node);
}
printk(KERN_DEBUG "\n");
}
#else
#define ext4_print_pending_tree(inode)
#endif
int __init ext4_init_pending(void)
{
ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation",
sizeof(struct pending_reservation),
0, (SLAB_RECLAIM_ACCOUNT), NULL);
if (ext4_pending_cachep == NULL)
return -ENOMEM;
return 0;
}
void ext4_exit_pending(void)
{
kmem_cache_destroy(ext4_pending_cachep);
}
void ext4_init_pending_tree(struct ext4_pending_tree *tree)
{
tree->root = RB_ROOT;
}
/*
* __get_pending - retrieve a pointer to a pending reservation
*
* @inode - file containing the pending cluster reservation
* @lclu - logical cluster of interest
*
* Returns a pointer to a pending reservation if it's a member of
* the set, and NULL if not. Must be called holding i_es_lock.
*/
static struct pending_reservation *__get_pending(struct inode *inode,
ext4_lblk_t lclu)
{
struct ext4_pending_tree *tree;
struct rb_node *node;
struct pending_reservation *pr = NULL;
tree = &EXT4_I(inode)->i_pending_tree;
node = (&tree->root)->rb_node;
while (node) {
pr = rb_entry(node, struct pending_reservation, rb_node);
if (lclu < pr->lclu)
node = node->rb_left;
else if (lclu > pr->lclu)
node = node->rb_right;
else if (lclu == pr->lclu)
return pr;
}
return NULL;
}
/*
* __insert_pending - adds a pending cluster reservation to the set of
* pending reservations
*
* @inode - file containing the cluster
* @lblk - logical block in the cluster to be added
*
* Returns 0 on successful insertion and -ENOMEM on failure. If the
* pending reservation is already in the set, returns successfully.
*/
static int __insert_pending(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree;
struct rb_node **p = &tree->root.rb_node;
struct rb_node *parent = NULL;
struct pending_reservation *pr;
ext4_lblk_t lclu;
int ret = 0;
lclu = EXT4_B2C(sbi, lblk);
/* search to find parent for insertion */
while (*p) {
parent = *p;
pr = rb_entry(parent, struct pending_reservation, rb_node);
if (lclu < pr->lclu) {
p = &(*p)->rb_left;
} else if (lclu > pr->lclu) {
p = &(*p)->rb_right;
} else {
/* pending reservation already inserted */
goto out;
}
}
pr = kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC);
if (pr == NULL) {
ret = -ENOMEM;
goto out;
}
pr->lclu = lclu;
rb_link_node(&pr->rb_node, parent, p);
rb_insert_color(&pr->rb_node, &tree->root);
out:
return ret;
}
/*
* __remove_pending - removes a pending cluster reservation from the set
* of pending reservations
*
* @inode - file containing the cluster
* @lblk - logical block in the pending cluster reservation to be removed
*
* Returns successfully if pending reservation is not a member of the set.
*/
static void __remove_pending(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct pending_reservation *pr;
struct ext4_pending_tree *tree;
pr = __get_pending(inode, EXT4_B2C(sbi, lblk));
if (pr != NULL) {
tree = &EXT4_I(inode)->i_pending_tree;
rb_erase(&pr->rb_node, &tree->root);
kmem_cache_free(ext4_pending_cachep, pr);
}
}
/*
* ext4_remove_pending - removes a pending cluster reservation from the set
* of pending reservations
*
* @inode - file containing the cluster
* @lblk - logical block in the pending cluster reservation to be removed
*
* Locking for external use of __remove_pending.
*/
void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_inode_info *ei = EXT4_I(inode);
write_lock(&ei->i_es_lock);
__remove_pending(inode, lblk);
write_unlock(&ei->i_es_lock);
}
/*
* ext4_is_pending - determine whether a cluster has a pending reservation
* on it
*
* @inode - file containing the cluster
* @lblk - logical block in the cluster
*
* Returns true if there's a pending reservation for the cluster in the
* set of pending reservations, and false if not.
*/
bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
bool ret;
read_lock(&ei->i_es_lock);
ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL);
read_unlock(&ei->i_es_lock);
return ret;
}
/*
* ext4_es_insert_delayed_block - adds a delayed block to the extents status
* tree, adding a pending reservation where
* needed
*
* @inode - file containing the newly added block
* @lblk - logical block to be added
* @allocated - indicates whether a physical cluster has been allocated for
* the logical cluster that contains the block
*
* Returns 0 on success, negative error code on failure.
*/
int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
bool allocated)
{
struct extent_status newes;
int err = 0;
es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
lblk, inode->i_ino);
newes.es_lblk = lblk;
newes.es_len = 1;
ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
ext4_es_insert_extent_check(inode, &newes);
write_lock(&EXT4_I(inode)->i_es_lock);
err = __es_remove_extent(inode, lblk, lblk);
if (err != 0)
goto error;
retry:
err = __es_insert_extent(inode, &newes);
if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
128, EXT4_I(inode)))
goto retry;
if (err != 0)
goto error;
if (allocated)
__insert_pending(inode, lblk);
error:
write_unlock(&EXT4_I(inode)->i_es_lock);
ext4_es_print_tree(inode);
ext4_print_pending_tree(inode);
return err;
}
/*
* __es_delayed_clu - count number of clusters containing blocks that
* are delayed only
*
* @inode - file containing block range
* @start - logical block defining start of range
* @end - logical block defining end of range
*
* Returns the number of clusters containing only delayed (not delayed
* and unwritten) blocks in the range specified by @start and @end. Any
* cluster or part of a cluster within the range and containing a delayed
* and not unwritten block within the range is counted as a whole cluster.
*/
static unsigned int __es_delayed_clu(struct inode *inode, ext4_lblk_t start,
ext4_lblk_t end)
{
struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
struct extent_status *es;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct rb_node *node;
ext4_lblk_t first_lclu, last_lclu;
unsigned long long last_counted_lclu;
unsigned int n = 0;
/* guaranteed to be unequal to any ext4_lblk_t value */
last_counted_lclu = ~0ULL;
es = __es_tree_search(&tree->root, start);
while (es && (es->es_lblk <= end)) {
if (ext4_es_is_delonly(es)) {
if (es->es_lblk <= start)
first_lclu = EXT4_B2C(sbi, start);
else
first_lclu = EXT4_B2C(sbi, es->es_lblk);
if (ext4_es_end(es) >= end)
last_lclu = EXT4_B2C(sbi, end);
else
last_lclu = EXT4_B2C(sbi, ext4_es_end(es));
if (first_lclu == last_counted_lclu)
n += last_lclu - first_lclu;
else
n += last_lclu - first_lclu + 1;
last_counted_lclu = last_lclu;
}
node = rb_next(&es->rb_node);
if (!node)
break;
es = rb_entry(node, struct extent_status, rb_node);
}
return n;
}
/*
* ext4_es_delayed_clu - count number of clusters containing blocks that
* are both delayed and unwritten
*
* @inode - file containing block range
* @lblk - logical block defining start of range
* @len - number of blocks in range
*
* Locking for external use of __es_delayed_clu().
*/
unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len)
{
struct ext4_inode_info *ei = EXT4_I(inode);
ext4_lblk_t end;
unsigned int n;
if (len == 0)
return 0;
end = lblk + len - 1;
WARN_ON(end < lblk);
read_lock(&ei->i_es_lock);
n = __es_delayed_clu(inode, lblk, end);
read_unlock(&ei->i_es_lock);
return n;
}
/*
* __revise_pending - makes, cancels, or leaves unchanged pending cluster
* reservations for a specified block range depending
* upon the presence or absence of delayed blocks
* outside the range within clusters at the ends of the
* range
*
* @inode - file containing the range
* @lblk - logical block defining the start of range
* @len - length of range in blocks
*
* Used after a newly allocated extent is added to the extents status tree.
* Requires that the extents in the range have either written or unwritten
* status. Must be called while holding i_es_lock.
*/
static void __revise_pending(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t end = lblk + len - 1;
ext4_lblk_t first, last;
bool f_del = false, l_del = false;
if (len == 0)
return;
/*
* Two cases - block range within single cluster and block range
* spanning two or more clusters. Note that a cluster belonging
* to a range starting and/or ending on a cluster boundary is treated
* as if it does not contain a delayed extent. The new range may
* have allocated space for previously delayed blocks out to the
* cluster boundary, requiring that any pre-existing pending
* reservation be canceled. Because this code only looks at blocks
* outside the range, it should revise pending reservations
* correctly even if the extent represented by the range can't be
* inserted in the extents status tree due to ENOSPC.
*/
if (EXT4_B2C(sbi, lblk) == EXT4_B2C(sbi, end)) {
first = EXT4_LBLK_CMASK(sbi, lblk);
if (first != lblk)
f_del = __es_scan_range(inode, &ext4_es_is_delonly,
first, lblk - 1);
if (f_del) {
__insert_pending(inode, first);
} else {
last = EXT4_LBLK_CMASK(sbi, end) +
sbi->s_cluster_ratio - 1;
if (last != end)
l_del = __es_scan_range(inode,
&ext4_es_is_delonly,
end + 1, last);
if (l_del)
__insert_pending(inode, last);
else
__remove_pending(inode, last);
}
} else {
first = EXT4_LBLK_CMASK(sbi, lblk);
if (first != lblk)
f_del = __es_scan_range(inode, &ext4_es_is_delonly,
first, lblk - 1);
if (f_del)
__insert_pending(inode, first);
else
__remove_pending(inode, first);
last = EXT4_LBLK_CMASK(sbi, end) + sbi->s_cluster_ratio - 1;
if (last != end)
l_del = __es_scan_range(inode, &ext4_es_is_delonly,
end + 1, last);
if (l_del)
__insert_pending(inode, last);
else
__remove_pending(inode, last);
}
}
/*
* ext4_es_remove_blks - remove block range from extents status tree and
* reduce reservation count or cancel pending
* reservation as needed
*
* @inode - file containing range
* @lblk - first block in range
* @len - number of blocks to remove
*
*/
void ext4_es_remove_blks(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
unsigned int clu_size, reserved = 0;
ext4_lblk_t last_lclu, first, length, remainder, last;
bool delonly;
int err = 0;
struct pending_reservation *pr;
struct ext4_pending_tree *tree;
/*
* Process cluster by cluster for bigalloc - there may be up to
* two clusters in a 4k page with a 1k block size and two blocks
* per cluster. Also necessary for systems with larger page sizes
* and potentially larger block sizes.
*/
clu_size = sbi->s_cluster_ratio;
last_lclu = EXT4_B2C(sbi, lblk + len - 1);
write_lock(&EXT4_I(inode)->i_es_lock);
for (first = lblk, remainder = len;
remainder > 0;
first += length, remainder -= length) {
if (EXT4_B2C(sbi, first) == last_lclu)
length = remainder;
else
length = clu_size - EXT4_LBLK_COFF(sbi, first);
/*
* The BH_Delay flag, which triggers calls to this function,
* and the contents of the extents status tree can be
* inconsistent due to writepages activity. So, note whether
* the blocks to be removed actually belong to an extent with
* delayed only status.
*/
delonly = __es_scan_clu(inode, &ext4_es_is_delonly, first);
/*
* because of the writepages effect, written and unwritten
* blocks could be removed here
*/
last = first + length - 1;
err = __es_remove_extent(inode, first, last);
if (err)
ext4_warning(inode->i_sb,
"%s: couldn't remove page (err = %d)",
__func__, err);
/* non-bigalloc case: simply count the cluster for release */
if (sbi->s_cluster_ratio == 1 && delonly) {
reserved++;
continue;
}
/*
* bigalloc case: if all delayed allocated only blocks have
* just been removed from a cluster, either cancel a pending
* reservation if it exists or count a cluster for release
*/
if (delonly &&
!__es_scan_clu(inode, &ext4_es_is_delonly, first)) {
pr = __get_pending(inode, EXT4_B2C(sbi, first));
if (pr != NULL) {
tree = &EXT4_I(inode)->i_pending_tree;
rb_erase(&pr->rb_node, &tree->root);
kmem_cache_free(ext4_pending_cachep, pr);
} else {
reserved++;
}
}
}
write_unlock(&EXT4_I(inode)->i_es_lock);
ext4_da_release_space(inode, reserved);
}

80
fs/ext4/extents_status.h
View File

@ -78,6 +78,51 @@ struct ext4_es_stats {
struct percpu_counter es_stats_shk_cnt;
};
/*
* Pending cluster reservations for bigalloc file systems
*
* A cluster with a pending reservation is a logical cluster shared by at
* least one extent in the extents status tree with delayed and unwritten
* status and at least one other written or unwritten extent. The
* reservation is said to be pending because a cluster reservation would
* have to be taken in the event all blocks in the cluster shared with
* written or unwritten extents were deleted while the delayed and
* unwritten blocks remained.
*
* The set of pending cluster reservations is an auxiliary data structure
* used with the extents status tree to implement reserved cluster/block
* accounting for bigalloc file systems. The set is kept in memory and
* records all pending cluster reservations.
*
* Its primary function is to avoid the need to read extents from the
* disk when invalidating pages as a result of a truncate, punch hole, or
* collapse range operation. Page invalidation requires a decrease in the
* reserved cluster count if it results in the removal of all delayed
* and unwritten extents (blocks) from a cluster that is not shared with a
* written or unwritten extent, and no decrease otherwise. Determining
* whether the cluster is shared can be done by searching for a pending
* reservation on it.
*
* Secondarily, it provides a potentially faster method for determining
* whether the reserved cluster count should be increased when a physical
* cluster is deallocated as a result of a truncate, punch hole, or
* collapse range operation. The necessary information is also present
* in the extents status tree, but might be more rapidly accessed in
* the pending reservation set in many cases due to smaller size.
*
* The pending cluster reservation set is implemented as a red-black tree
* with the goal of minimizing per page search time overhead.
*/
struct pending_reservation {
struct rb_node rb_node;
ext4_lblk_t lclu;
};
struct ext4_pending_tree {
struct rb_root root;
};
extern int __init ext4_init_es(void);
extern void ext4_exit_es(void);
extern void ext4_es_init_tree(struct ext4_es_tree *tree);
@ -90,11 +135,18 @@ extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
unsigned int status);
extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
extern void ext4_es_find_delayed_extent_range(struct inode *inode,
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es);
extern void ext4_es_find_extent_range(struct inode *inode,
int (*match_fn)(struct extent_status *es),
ext4_lblk_t lblk, ext4_lblk_t end,
struct extent_status *es);
extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
struct extent_status *es);
extern bool ext4_es_scan_range(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk, ext4_lblk_t end);
extern bool ext4_es_scan_clu(struct inode *inode,
int (*matching_fn)(struct extent_status *es),
ext4_lblk_t lblk);
static inline unsigned int ext4_es_status(struct extent_status *es)
{
@ -126,6 +178,16 @@ static inline int ext4_es_is_hole(struct extent_status *es)
return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
}
static inline int ext4_es_is_mapped(struct extent_status *es)
{
return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
}
static inline int ext4_es_is_delonly(struct extent_status *es)
{
return (ext4_es_is_delayed(es) && !ext4_es_is_unwritten(es));
}
static inline void ext4_es_set_referenced(struct extent_status *es)
{
es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
@ -175,4 +237,16 @@ extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
extern int __init ext4_init_pending(void);
extern void ext4_exit_pending(void);
extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
extern int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
bool allocated);
extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
extern void ext4_es_remove_blks(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
#endif /* _EXT4_EXTENTS_STATUS_H */

2
fs/ext4/inline.c
View File

@ -863,7 +863,7 @@ int ext4_da_write_inline_data_begin(struct address_space *mapping,
handle_t *handle;
struct page *page;
struct ext4_iloc iloc;
int retries;
int retries = 0;
ret = ext4_get_inode_loc(inode, &iloc);
if (ret)

142
fs/ext4/inode.c
View File

@ -577,8 +577,8 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
!(status & EXTENT_STATUS_WRITTEN) &&
ext4_find_delalloc_range(inode, map->m_lblk,
map->m_lblk + map->m_len - 1))
ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
map->m_lblk + map->m_len - 1))
status |= EXTENT_STATUS_DELAYED;
ret = ext4_es_insert_extent(inode, map->m_lblk,
map->m_len, map->m_pblk, status);
@ -701,8 +701,8 @@ found:
EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
!(status & EXTENT_STATUS_WRITTEN) &&
ext4_find_delalloc_range(inode, map->m_lblk,
map->m_lblk + map->m_len - 1))
ext4_es_scan_range(inode, &ext4_es_is_delayed, map->m_lblk,
map->m_lblk + map->m_len - 1))
status |= EXTENT_STATUS_DELAYED;
ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
map->m_pblk, status);
@ -1595,7 +1595,7 @@ static int ext4_da_reserve_space(struct inode *inode)
return 0; /* success */
}
static void ext4_da_release_space(struct inode *inode, int to_free)
void ext4_da_release_space(struct inode *inode, int to_free)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct ext4_inode_info *ei = EXT4_I(inode);
@ -1634,13 +1634,11 @@ static void ext4_da_page_release_reservation(struct page *page,
unsigned int offset,
unsigned int length)
{
int to_release = 0, contiguous_blks = 0;
int contiguous_blks = 0;
struct buffer_head *head, *bh;
unsigned int curr_off = 0;
struct inode *inode = page->mapping->host;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
unsigned int stop = offset + length;
int num_clusters;
ext4_fsblk_t lblk;
BUG_ON(stop > PAGE_SIZE || stop < length);
@ -1654,7 +1652,6 @@ static void ext4_da_page_release_reservation(struct page *page,
break;
if ((offset <= curr_off) && (buffer_delay(bh))) {
to_release++;
contiguous_blks++;
clear_buffer_delay(bh);
} else if (contiguous_blks) {
@ -1662,7 +1659,7 @@ static void ext4_da_page_release_reservation(struct page *page,
(PAGE_SHIFT - inode->i_blkbits);
lblk += (curr_off >> inode->i_blkbits) -
contiguous_blks;
ext4_es_remove_extent(inode, lblk, contiguous_blks);
ext4_es_remove_blks(inode, lblk, contiguous_blks);
contiguous_blks = 0;
}
curr_off = next_off;
@ -1671,21 +1668,9 @@ static void ext4_da_page_release_reservation(struct page *page,
if (contiguous_blks) {
lblk = page->index << (PAGE_SHIFT - inode->i_blkbits);
lblk += (curr_off >> inode->i_blkbits) - contiguous_blks;
ext4_es_remove_extent(inode, lblk, contiguous_blks);
ext4_es_remove_blks(inode, lblk, contiguous_blks);
}
/* If we have released all the blocks belonging to a cluster, then we
* need to release the reserved space for that cluster. */
num_clusters = EXT4_NUM_B2C(sbi, to_release);
while (num_clusters > 0) {
lblk = (page->index << (PAGE_SHIFT - inode->i_blkbits)) +
((num_clusters - 1) << sbi->s_cluster_bits);
if (sbi->s_cluster_ratio == 1 ||
!ext4_find_delalloc_cluster(inode, lblk))
ext4_da_release_space(inode, 1);
num_clusters--;
}
}
/*
@ -1780,6 +1765,65 @@ static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
}
/*
* ext4_insert_delayed_block - adds a delayed block to the extents status
* tree, incrementing the reserved cluster/block
* count or making a pending reservation
* where needed
*
* @inode - file containing the newly added block
* @lblk - logical block to be added
*
* Returns 0 on success, negative error code on failure.
*/
static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int ret;
bool allocated = false;
/*
* If the cluster containing lblk is shared with a delayed,
* written, or unwritten extent in a bigalloc file system, it's
* already been accounted for and does not need to be reserved.
* A pending reservation must be made for the cluster if it's
* shared with a written or unwritten extent and doesn't already
* have one. Written and unwritten extents can be purged from the
* extents status tree if the system is under memory pressure, so
* it's necessary to examine the extent tree if a search of the
* extents status tree doesn't get a match.
*/
if (sbi->s_cluster_ratio == 1) {
ret = ext4_da_reserve_space(inode);
if (ret != 0) /* ENOSPC */
goto errout;
} else { /* bigalloc */
if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) {
if (!ext4_es_scan_clu(inode,
&ext4_es_is_mapped, lblk)) {
ret = ext4_clu_mapped(inode,
EXT4_B2C(sbi, lblk));
if (ret < 0)
goto errout;
if (ret == 0) {
ret = ext4_da_reserve_space(inode);
if (ret != 0) /* ENOSPC */
goto errout;
} else {
allocated = true;
}
} else {
allocated = true;
}
}
}
ret = ext4_es_insert_delayed_block(inode, lblk, allocated);
errout:
return ret;
}
/*
* This function is grabs code from the very beginning of
* ext4_map_blocks, but assumes that the caller is from delayed write
@ -1859,28 +1903,14 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
add_delayed:
if (retval == 0) {
int ret;
/*
* XXX: __block_prepare_write() unmaps passed block,
* is it OK?
*/
/*
* If the block was allocated from previously allocated cluster,
* then we don't need to reserve it again. However we still need
* to reserve metadata for every block we're going to write.
*/
if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 ||
!ext4_find_delalloc_cluster(inode, map->m_lblk)) {
ret = ext4_da_reserve_space(inode);
if (ret) {
/* not enough space to reserve */
retval = ret;
goto out_unlock;
}
}
ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
~0, EXTENT_STATUS_DELAYED);
if (ret) {
ret = ext4_insert_delayed_block(inode, map->m_lblk);
if (ret != 0) {
retval = ret;
goto out_unlock;
}
@ -3450,7 +3480,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
ext4_lblk_t end = map.m_lblk + map.m_len - 1;
struct extent_status es;
ext4_es_find_delayed_extent_range(inode, map.m_lblk, end, &es);
ext4_es_find_extent_range(inode, &ext4_es_is_delayed,
map.m_lblk, end, &es);
if (!es.es_len || es.es_lblk > end) {
/* entire range is a hole */
@ -6153,13 +6184,14 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
return !buffer_mapped(bh);
}
int ext4_page_mkwrite(struct vm_fault *vmf)
vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct page *page = vmf->page;
loff_t size;
unsigned long len;
int ret;
int err;
vm_fault_t ret;
struct file *file = vma->vm_file;
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
@ -6172,8 +6204,8 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
down_read(&EXT4_I(inode)->i_mmap_sem);
ret = ext4_convert_inline_data(inode);
if (ret)
err = ext4_convert_inline_data(inode);
if (err)
goto out_ret;
/* Delalloc case is easy... */
@ -6181,9 +6213,9 @@ int ext4_page_mkwrite(struct vm_fault *vmf)
!ext4_should_journal_data(inode) &&
!ext4_nonda_switch(inode->i_sb)) {
do {
ret = block_page_mkwrite(vma, vmf,
err = block_page_mkwrite(vma, vmf,
ext4_da_get_block_prep);
} while (ret == -ENOSPC &&
} while (err == -ENOSPC &&
ext4_should_retry_alloc(inode->i_sb, &retries));
goto out_ret;
}
@ -6228,8 +6260,8 @@ retry_alloc:
ret = VM_FAULT_SIGBUS;
goto out;
}
ret = block_page_mkwrite(vma, vmf, get_block);
if (!ret && ext4_should_journal_data(inode)) {
err = block_page_mkwrite(vma, vmf, get_block);
if (!err && ext4_should_journal_data(inode)) {
if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
PAGE_SIZE, NULL, do_journal_get_write_access)) {
unlock_page(page);
@ -6240,24 +6272,24 @@ retry_alloc:
ext4_set_inode_state(inode, EXT4_STATE_JDATA);
}
ext4_journal_stop(handle);
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
if (err == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry_alloc;
out_ret:
ret = block_page_mkwrite_return(ret);
ret = block_page_mkwrite_return(err);
out:
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(inode->i_sb);
return ret;
}
int ext4_filemap_fault(struct vm_fault *vmf)
vm_fault_t ext4_filemap_fault(struct vm_fault *vmf)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
int err;
vm_fault_t ret;
down_read(&EXT4_I(inode)->i_mmap_sem);
err = filemap_fault(vmf);
ret = filemap_fault(vmf);
up_read(&EXT4_I(inode)->i_mmap_sem);
return err;
return ret;
}

97
fs/ext4/ioctl.c
View File

@ -67,7 +67,6 @@ static void swap_inode_data(struct inode *inode1, struct inode *inode2)
ei1 = EXT4_I(inode1);
ei2 = EXT4_I(inode2);
swap(inode1->i_flags, inode2->i_flags);
swap(inode1->i_version, inode2->i_version);
swap(inode1->i_blocks, inode2->i_blocks);
swap(inode1->i_bytes, inode2->i_bytes);
@ -85,6 +84,21 @@ static void swap_inode_data(struct inode *inode1, struct inode *inode2)
i_size_write(inode2, isize);
}
static void reset_inode_seed(struct inode *inode)
{
struct ext4_inode_info *ei = EXT4_I(inode);
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
__le32 inum = cpu_to_le32(inode->i_ino);
__le32 gen = cpu_to_le32(inode->i_generation);
__u32 csum;
if (!ext4_has_metadata_csum(inode->i_sb))
return;
csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, sizeof(inum));
ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, sizeof(gen));
}
/**
* Swap the information from the given @inode and the inode
* EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
@ -102,10 +116,13 @@ static long swap_inode_boot_loader(struct super_block *sb,
struct inode *inode_bl;
struct ext4_inode_info *ei_bl;
if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode) ||
IS_SWAPFILE(inode) || IS_ENCRYPTED(inode) ||
ext4_has_inline_data(inode))
return -EINVAL;
if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
if (IS_RDONLY(inode) || IS_APPEND(inode) || IS_IMMUTABLE(inode) ||
!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
return -EPERM;
inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
@ -120,13 +137,13 @@ static long swap_inode_boot_loader(struct super_block *sb,
* that only 1 swap_inode_boot_loader is running. */
lock_two_nondirectories(inode, inode_bl);
truncate_inode_pages(&inode->i_data, 0);
truncate_inode_pages(&inode_bl->i_data, 0);
/* Wait for all existing dio workers */
inode_dio_wait(inode);
inode_dio_wait(inode_bl);
truncate_inode_pages(&inode->i_data, 0);
truncate_inode_pages(&inode_bl->i_data, 0);
handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
if (IS_ERR(handle)) {
err = -EINVAL;
@ -159,6 +176,8 @@ static long swap_inode_boot_loader(struct super_block *sb,
inode->i_generation = prandom_u32();
inode_bl->i_generation = prandom_u32();
reset_inode_seed(inode);
reset_inode_seed(inode_bl);
ext4_discard_preallocations(inode);
@ -169,6 +188,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
inode->i_ino, err);
/* Revert all changes: */
swap_inode_data(inode, inode_bl);
ext4_mark_inode_dirty(handle, inode);
} else {
err = ext4_mark_inode_dirty(handle, inode_bl);
if (err < 0) {
@ -178,6 +198,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
/* Revert all changes: */
swap_inode_data(inode, inode_bl);
ext4_mark_inode_dirty(handle, inode);
ext4_mark_inode_dirty(handle, inode_bl);
}
}
ext4_journal_stop(handle);
@ -339,19 +360,14 @@ static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
return 0;
err = mnt_want_write_file(filp);
if (err)
return err;
err = -EPERM;
inode_lock(inode);
/* Is it quota file? Do not allow user to mess with it */
if (ext4_is_quota_file(inode))
goto out_unlock;
return err;
err = ext4_get_inode_loc(inode, &iloc);
if (err)
goto out_unlock;
return err;
raw_inode = ext4_raw_inode(&iloc);
if (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) {
@ -359,20 +375,20 @@ static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
EXT4_SB(sb)->s_want_extra_isize,
&iloc);
if (err)
goto out_unlock;
return err;
} else {
brelse(iloc.bh);
}
dquot_initialize(inode);
err = dquot_initialize(inode);
if (err)
return err;
handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
EXT4_QUOTA_INIT_BLOCKS(sb) +
EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto out_unlock;
}
if (IS_ERR(handle))
return PTR_ERR(handle);
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err)
@ -400,9 +416,6 @@ out_dirty:
err = rc;
out_stop:
ext4_journal_stop(handle);
out_unlock:
inode_unlock(inode);
mnt_drop_write_file(filp);
return err;
}
#else
@ -626,6 +639,30 @@ group_add_out:
return err;
}
static int ext4_ioctl_check_project(struct inode *inode, struct fsxattr *fa)
{
/*
* Project Quota ID state is only allowed to change from within the init
* namespace. Enforce that restriction only if we are trying to change
* the quota ID state. Everything else is allowed in user namespaces.
*/
if (current_user_ns() == &init_user_ns)
return 0;
if (__kprojid_val(EXT4_I(inode)->i_projid) != fa->fsx_projid)
return -EINVAL;
if (ext4_test_inode_flag(inode, EXT4_INODE_PROJINHERIT)) {
if (!(fa->fsx_xflags & FS_XFLAG_PROJINHERIT))
return -EINVAL;
} else {
if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT)
return -EINVAL;
}
return 0;
}
long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@ -1025,19 +1062,19 @@ resizefs_out:
return err;
inode_lock(inode);
err = ext4_ioctl_check_project(inode, &fa);
if (err)
goto out;
flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
(flags & EXT4_FL_XFLAG_VISIBLE);
err = ext4_ioctl_setflags(inode, flags);
if (err)
goto out;
err = ext4_ioctl_setproject(filp, fa.fsx_projid);
out:
inode_unlock(inode);
mnt_drop_write_file(filp);
if (err)
return err;
err = ext4_ioctl_setproject(filp, fa.fsx_projid);
if (err)
return err;
return 0;
return err;
}
case EXT4_IOC_SHUTDOWN:
return ext4_shutdown(sb, arg);

14
fs/ext4/mballoc.c
View File

@ -4915,9 +4915,17 @@ do_more:
&sbi->s_flex_groups[flex_group].free_clusters);
}
if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
/*
* on a bigalloc file system, defer the s_freeclusters_counter
* update to the caller (ext4_remove_space and friends) so they
* can determine if a cluster freed here should be rereserved
*/
if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
percpu_counter_add(&sbi->s_freeclusters_counter,
count_clusters);
}
ext4_mb_unload_buddy(&e4b);

8
fs/ext4/move_extent.c
View File

@ -516,9 +516,13 @@ mext_check_arguments(struct inode *orig_inode,
orig_inode->i_ino, donor_inode->i_ino);
return -EINVAL;
}
if (orig_eof < orig_start + *len - 1)
if (orig_eof <= orig_start)
*len = 0;
else if (orig_eof < orig_start + *len - 1)
*len = orig_eof - orig_start;
if (donor_eof < donor_start + *len - 1)
if (donor_eof <= donor_start)
*len = 0;
else if (donor_eof < donor_start + *len - 1)
*len = donor_eof - donor_start;
if (!*len) {
ext4_debug("ext4 move extent: len should not be 0 "

2
fs/ext4/namei.c
View File

@ -2261,7 +2261,7 @@ again:
dxroot->info.indirect_levels += 1;
dxtrace(printk(KERN_DEBUG
"Creating %d level index...\n",
info->indirect_levels));
dxroot->info.indirect_levels));
err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;

81
fs/ext4/super.c
View File

@ -914,6 +914,18 @@ static inline void ext4_quota_off_umount(struct super_block *sb)
for (type = 0; type < EXT4_MAXQUOTAS; type++)
ext4_quota_off(sb, type);
}
/*
* This is a helper function which is used in the mount/remount
* codepaths (which holds s_umount) to fetch the quota file name.
*/
static inline char *get_qf_name(struct super_block *sb,
struct ext4_sb_info *sbi,
int type)
{
return rcu_dereference_protected(sbi->s_qf_names[type],
lockdep_is_held(&sb->s_umount));
}
#else
static inline void ext4_quota_off_umount(struct super_block *sb)
{
@ -965,7 +977,7 @@ static void ext4_put_super(struct super_block *sb)
percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
#ifdef CONFIG_QUOTA
for (i = 0; i < EXT4_MAXQUOTAS; i++)
kfree(sbi->s_qf_names[i]);
kfree(get_qf_name(sb, sbi, i));
#endif
/* Debugging code just in case the in-memory inode orphan list
@ -1040,6 +1052,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
ei->i_da_metadata_calc_len = 0;
ei->i_da_metadata_calc_last_lblock = 0;
spin_lock_init(&(ei->i_block_reservation_lock));
ext4_init_pending_tree(&ei->i_pending_tree);
#ifdef CONFIG_QUOTA
ei->i_reserved_quota = 0;
memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
@ -1530,11 +1543,10 @@ static const char deprecated_msg[] =
static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
char *qname;
char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
int ret = -1;
if (sb_any_quota_loaded(sb) &&
!sbi->s_qf_names[qtype]) {
if (sb_any_quota_loaded(sb) && !old_qname) {
ext4_msg(sb, KERN_ERR,
"Cannot change journaled "
"quota options when quota turned on");
@ -1551,8 +1563,8 @@ static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
"Not enough memory for storing quotafile name");
return -1;
}
if (sbi->s_qf_names[qtype]) {
if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
if (old_qname) {
if (strcmp(old_qname, qname) == 0)
ret = 1;
else
ext4_msg(sb, KERN_ERR,
@ -1565,7 +1577,7 @@ static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
"quotafile must be on filesystem root");
goto errout;
}
sbi->s_qf_names[qtype] = qname;
rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
set_opt(sb, QUOTA);
return 1;
errout:
@ -1577,15 +1589,16 @@ static int clear_qf_name(struct super_block *sb, int qtype)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
char *old_qname = get_qf_name(sb, sbi, qtype);
if (sb_any_quota_loaded(sb) &&
sbi->s_qf_names[qtype]) {
if (sb_any_quota_loaded(sb) && old_qname) {
ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
" when quota turned on");
return -1;
}
kfree(sbi->s_qf_names[qtype]);
sbi->s_qf_names[qtype] = NULL;
rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
synchronize_rcu();
kfree(old_qname);
return 1;
}
#endif
@ -1960,7 +1973,7 @@ static int parse_options(char *options, struct super_block *sb,
int is_remount)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
char *p;
char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
substring_t args[MAX_OPT_ARGS];
int token;
@ -1991,11 +2004,13 @@ static int parse_options(char *options, struct super_block *sb,
"Cannot enable project quota enforcement.");
return 0;
}
if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
if (usr_qf_name || grp_qf_name) {
if (test_opt(sb, USRQUOTA) && usr_qf_name)
clear_opt(sb, USRQUOTA);
if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
if (test_opt(sb, GRPQUOTA) && grp_qf_name)
clear_opt(sb, GRPQUOTA);
if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
@ -2029,6 +2044,7 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
{
#if defined(CONFIG_QUOTA)
struct ext4_sb_info *sbi = EXT4_SB(sb);
char *usr_qf_name, *grp_qf_name;
if (sbi->s_jquota_fmt) {
char *fmtname = "";
@ -2047,11 +2063,14 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
seq_printf(seq, ",jqfmt=%s", fmtname);
}
if (sbi->s_qf_names[USRQUOTA])
seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
if (sbi->s_qf_names[GRPQUOTA])
seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
rcu_read_lock();
usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
if (usr_qf_name)
seq_show_option(seq, "usrjquota", usr_qf_name);
if (grp_qf_name)
seq_show_option(seq, "grpjquota", grp_qf_name);
rcu_read_unlock();
#endif
}
@ -5103,6 +5122,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
int err = 0;
#ifdef CONFIG_QUOTA
int i, j;
char *to_free[EXT4_MAXQUOTAS];
#endif
char *orig_data = kstrdup(data, GFP_KERNEL);
@ -5122,8 +5142,9 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
for (i = 0; i < EXT4_MAXQUOTAS; i++)
if (sbi->s_qf_names[i]) {
old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
GFP_KERNEL);
char *qf_name = get_qf_name(sb, sbi, i);
old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
if (!old_opts.s_qf_names[i]) {
for (j = 0; j < i; j++)
kfree(old_opts.s_qf_names[j]);
@ -5352,9 +5373,12 @@ restore_opts:
#ifdef CONFIG_QUOTA
sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
for (i = 0; i < EXT4_MAXQUOTAS; i++) {
kfree(sbi->s_qf_names[i]);
sbi->s_qf_names[i] = old_opts.s_qf_names[i];
to_free[i] = get_qf_name(sb, sbi, i);
rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
}
synchronize_rcu();
for (i = 0; i < EXT4_MAXQUOTAS; i++)
kfree(to_free[i]);
#endif
kfree(orig_data);
return err;
@ -5545,7 +5569,7 @@ static int ext4_write_info(struct super_block *sb, int type)
*/
static int ext4_quota_on_mount(struct super_block *sb, int type)
{
return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
EXT4_SB(sb)->s_jquota_fmt, type);
}
@ -5954,6 +5978,10 @@ static int __init ext4_init_fs(void)
if (err)
return err;
err = ext4_init_pending();
if (err)
goto out6;
err = ext4_init_pageio();
if (err)
goto out5;
@ -5992,6 +6020,8 @@ out3:
out4:
ext4_exit_pageio();
out5:
ext4_exit_pending();
out6:
ext4_exit_es();
return err;
@ -6009,6 +6039,7 @@ static void __exit ext4_exit_fs(void)
ext4_exit_system_zone();
ext4_exit_pageio();
ext4_exit_es();
ext4_exit_pending();
}
MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");

4
fs/jbd2/checkpoint.c
View File

@ -251,8 +251,8 @@ restart:
bh = jh2bh(jh);
if (buffer_locked(bh)) {
spin_unlock(&journal->j_list_lock);
get_bh(bh);
spin_unlock(&journal->j_list_lock);
wait_on_buffer(bh);
/* the journal_head may have gone by now */
BUFFER_TRACE(bh, "brelse");
@ -333,8 +333,8 @@ restart2:
jh = transaction->t_checkpoint_io_list;
bh = jh2bh(jh);
if (buffer_locked(bh)) {
spin_unlock(&journal->j_list_lock);
get_bh(bh);
spin_unlock(&journal->j_list_lock);
wait_on_buffer(bh);
/* the journal_head may have gone by now */
BUFFER_TRACE(bh, "brelse");

2
include/linux/buffer_head.h
View File

@ -242,7 +242,7 @@ int block_commit_write(struct page *page, unsigned from, unsigned to);
int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block);
/* Convert errno to return value from ->page_mkwrite() call */
static inline int block_page_mkwrite_return(int err)
static inline vm_fault_t block_page_mkwrite_return(int err)
{
if (err == 0)
return VM_FAULT_LOCKED;

99
include/trace/events/ext4.h
View File

@ -17,6 +17,7 @@ struct mpage_da_data;
struct ext4_map_blocks;
struct extent_status;
struct ext4_fsmap;
struct partial_cluster;
#define EXT4_I(inode) (container_of(inode, struct ext4_inode_info, vfs_inode))
@ -2035,21 +2036,23 @@ TRACE_EVENT(ext4_ext_show_extent,
);
TRACE_EVENT(ext4_remove_blocks,
TP_PROTO(struct inode *inode, struct ext4_extent *ex,
ext4_lblk_t from, ext4_fsblk_t to,
long long partial_cluster),
TP_PROTO(struct inode *inode, struct ext4_extent *ex,
ext4_lblk_t from, ext4_fsblk_t to,
struct partial_cluster *pc),
TP_ARGS(inode, ex, from, to, partial_cluster),
TP_ARGS(inode, ex, from, to, pc),
TP_STRUCT__entry(
__field( dev_t, dev )
__field( ino_t, ino )
__field( ext4_lblk_t, from )
__field( ext4_lblk_t, to )
__field( long long, partial )
__field( ext4_fsblk_t, ee_pblk )
__field( ext4_lblk_t, ee_lblk )
__field( unsigned short, ee_len )
__field( ext4_fsblk_t, pc_pclu )
__field( ext4_lblk_t, pc_lblk )
__field( int, pc_state)
),
TP_fast_assign(
@ -2057,14 +2060,16 @@ TRACE_EVENT(ext4_remove_blocks,
__entry->ino = inode->i_ino;
__entry->from = from;
__entry->to = to;
__entry->partial = partial_cluster;
__entry->ee_pblk = ext4_ext_pblock(ex);
__entry->ee_lblk = le32_to_cpu(ex->ee_block);
__entry->ee_len = ext4_ext_get_actual_len(ex);
__entry->pc_pclu = pc->pclu;
__entry->pc_lblk = pc->lblk;
__entry->pc_state = pc->state;
),
TP_printk("dev %d,%d ino %lu extent [%u(%llu), %u]"
"from %u to %u partial_cluster %lld",
"from %u to %u partial [pclu %lld lblk %u state %d]",
MAJOR(__entry->dev), MINOR(__entry->dev),
(unsigned long) __entry->ino,
(unsigned) __entry->ee_lblk,
@ -2072,45 +2077,53 @@ TRACE_EVENT(ext4_remove_blocks,
(unsigned short) __entry->ee_len,
(unsigned) __entry->from,
(unsigned) __entry->to,
(long long) __entry->partial)
(long long) __entry->pc_pclu,
(unsigned int) __entry->pc_lblk,
(int) __entry->pc_state)
);
TRACE_EVENT(ext4_ext_rm_leaf,
TP_PROTO(struct inode *inode, ext4_lblk_t start,
struct ext4_extent *ex,
long long partial_cluster),
struct partial_cluster *pc),
TP_ARGS(inode, start, ex, partial_cluster),
TP_ARGS(inode, start, ex, pc),
TP_STRUCT__entry(
__field( dev_t, dev )
__field( ino_t, ino )
__field( long long, partial )
__field( ext4_lblk_t, start )
__field( ext4_lblk_t, ee_lblk )
__field( ext4_fsblk_t, ee_pblk )
__field( short, ee_len )
__field( ext4_fsblk_t, pc_pclu )
__field( ext4_lblk_t, pc_lblk )
__field( int, pc_state)
),
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
__entry->partial = partial_cluster;
__entry->start = start;
__entry->ee_lblk = le32_to_cpu(ex->ee_block);
__entry->ee_pblk = ext4_ext_pblock(ex);
__entry->ee_len = ext4_ext_get_actual_len(ex);
__entry->pc_pclu = pc->pclu;
__entry->pc_lblk = pc->lblk;
__entry->pc_state = pc->state;
),
TP_printk("dev %d,%d ino %lu start_lblk %u last_extent [%u(%llu), %u]"
"partial_cluster %lld",
"partial [pclu %lld lblk %u state %d]",
MAJOR(__entry->dev), MINOR(__entry->dev),
(unsigned long) __entry->ino,
(unsigned) __entry->start,
(unsigned) __entry->ee_lblk,
(unsigned long long) __entry->ee_pblk,
(unsigned short) __entry->ee_len,
(long long) __entry->partial)
(long long) __entry->pc_pclu,
(unsigned int) __entry->pc_lblk,
(int) __entry->pc_state)
);
TRACE_EVENT(ext4_ext_rm_idx,
@ -2168,9 +2181,9 @@ TRACE_EVENT(ext4_ext_remove_space,
TRACE_EVENT(ext4_ext_remove_space_done,
TP_PROTO(struct inode *inode, ext4_lblk_t start, ext4_lblk_t end,
int depth, long long partial, __le16 eh_entries),
int depth, struct partial_cluster *pc, __le16 eh_entries),
TP_ARGS(inode, start, end, depth, partial, eh_entries),
TP_ARGS(inode, start, end, depth, pc, eh_entries),
TP_STRUCT__entry(
__field( dev_t, dev )
@ -2178,7 +2191,9 @@ TRACE_EVENT(ext4_ext_remove_space_done,
__field( ext4_lblk_t, start )
__field( ext4_lblk_t, end )
__field( int, depth )
__field( long long, partial )
__field( ext4_fsblk_t, pc_pclu )
__field( ext4_lblk_t, pc_lblk )
__field( int, pc_state )
__field( unsigned short, eh_entries )
),
@ -2188,18 +2203,23 @@ TRACE_EVENT(ext4_ext_remove_space_done,
__entry->start = start;
__entry->end = end;
__entry->depth = depth;
__entry->partial = partial;
__entry->pc_pclu = pc->pclu;
__entry->pc_lblk = pc->lblk;
__entry->pc_state = pc->state;
__entry->eh_entries = le16_to_cpu(eh_entries);
),
TP_printk("dev %d,%d ino %lu since %u end %u depth %d partial %lld "
TP_printk("dev %d,%d ino %lu since %u end %u depth %d "
"partial [pclu %lld lblk %u state %d] "
"remaining_entries %u",
MAJOR(__entry->dev), MINOR(__entry->dev),
(unsigned long) __entry->ino,
(unsigned) __entry->start,
(unsigned) __entry->end,
__entry->depth,
(long long) __entry->partial,
(long long) __entry->pc_pclu,
(unsigned int) __entry->pc_lblk,
(int) __entry->pc_state,
(unsigned short) __entry->eh_entries)
);
@ -2270,7 +2290,7 @@ TRACE_EVENT(ext4_es_remove_extent,
__entry->lblk, __entry->len)
);
TRACE_EVENT(ext4_es_find_delayed_extent_range_enter,
TRACE_EVENT(ext4_es_find_extent_range_enter,
TP_PROTO(struct inode *inode, ext4_lblk_t lblk),
TP_ARGS(inode, lblk),
@ -2292,7 +2312,7 @@ TRACE_EVENT(ext4_es_find_delayed_extent_range_enter,
(unsigned long) __entry->ino, __entry->lblk)
);
TRACE_EVENT(ext4_es_find_delayed_extent_range_exit,
TRACE_EVENT(ext4_es_find_extent_range_exit,
TP_PROTO(struct inode *inode, struct extent_status *es),
TP_ARGS(inode, es),
@ -2512,6 +2532,41 @@ TRACE_EVENT(ext4_es_shrink,
__entry->scan_time, __entry->nr_skipped, __entry->retried)
);
TRACE_EVENT(ext4_es_insert_delayed_block,
TP_PROTO(struct inode *inode, struct extent_status *es,
bool allocated),
TP_ARGS(inode, es, allocated),
TP_STRUCT__entry(
__field( dev_t, dev )
__field( ino_t, ino )
__field( ext4_lblk_t, lblk )
__field( ext4_lblk_t, len )
__field( ext4_fsblk_t, pblk )
__field( char, status )
__field( bool, allocated )
),
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
__entry->lblk = es->es_lblk;
__entry->len = es->es_len;
__entry->pblk = ext4_es_pblock(es);
__entry->status = ext4_es_status(es);
__entry->allocated = allocated;
),
TP_printk("dev %d,%d ino %lu es [%u/%u) mapped %llu status %s "
"allocated %d",
MAJOR(__entry->dev), MINOR(__entry->dev),
(unsigned long) __entry->ino,
__entry->lblk, __entry->len,
__entry->pblk, show_extent_status(__entry->status),
__entry->allocated)
);
/* fsmap traces */
DECLARE_EVENT_CLASS(ext4_fsmap_class,
TP_PROTO(struct super_block *sb, u32 keydev, u32 agno, u64 bno, u64 len,