[BUG]
When accessing a file on a crafted image, btrfs can crash in block layer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 136501067 P4D 136501067 PUD 124519067 PMD 0
CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252
RIP: 0010:end_bio_extent_readpage+0x144/0x700
Call Trace:
<IRQ>
blk_update_request+0x8f/0x350
blk_mq_end_request+0x1a/0x120
blk_done_softirq+0x99/0xc0
__do_softirq+0xc7/0x467
irq_exit+0xd1/0xe0
call_function_single_interrupt+0xf/0x20
</IRQ>
RIP: 0010:default_idle+0x1e/0x170
[CAUSE]
The crafted image has a tricky corruption, the INODE_ITEM has a
different type against its parent dir:
item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160
generation 13 transid 13 size 1048576 nbytes 1048576
block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0
sequence 9 flags 0x0(none)
This mode number 0120000 means it's a symlink.
But the dir item think it's still a regular file:
item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32
location key (268 INODE_ITEM 0) type FILE
transid 13 data_len 0 name_len 2
name: f4
For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it
empty, as symlink is only designed to have inlined extent, all handled
by tree block read. Thus no need to trigger btrfs_submit_bio_hook() for
inline file extent.
However end_bio_extent_readpage() expects tree->ops populated, as it's
reading regular data extent. This causes NULL pointer dereference.
[FIX]
This patch fixes the problem in two ways:
- Verify inode mode against its dir item when looking up inode
So in btrfs_lookup_dentry() if we find inode mode mismatch with dir
item, we error out so that corrupted inode will not be accessed.
- Verify inode mode when getting extent mapping
Only regular file should have regular or preallocated extent.
If we found regular/preallocated file extent for symlink or
the rest, we error out before submitting the read bio.
With this fix that crafted image can be rejected gracefully:
BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1
Reported-by: Yoon Jungyeon <jungyeon@gatech.edu>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Deduplicate the btrfs file type conversion implementation - file systems
that use the same file types as defined by POSIX do not need to define
their own versions and can use the common helper functions decared in
fs_types.h and implemented in fs_types.c
Common implementation can be found via commit:
bbe7449e25 "fs: common implementation of file type"
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
BUG_ON(1) leads to bogus warnings from clang when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set:
fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
BUG_ON(1);
^~~~~~~~~
include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here
max_chunk_size);
^~~~~~~~~~~~~~
include/linux/kernel.h:860:36: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once'
typeof(y) unique_y = (y); \
^
fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true
BUG_ON(1);
^
include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
^
fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning
u64 max_chunk_size;
^
= 0
Change it to BUG() so clang can see that this code path can never
continue.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs has the following different extent_io_trees used:
- fs_info::free_extents[2]
- btrfs_inode::io_tree - for both normal inodes and the btree inode
- btrfs_inode::io_failure_tree
- btrfs_transaction::dirty_pages
- btrfs_root::dirty_log_pages
If we want to trace changes in those trees, it will be pretty hard to
distinguish them.
Instead of using hard-to-read pointer address, this patch will introduce
a new member extent_io_tree::owner to track the owner.
This modification needs all the callers of extent_io_tree_init() to
accept a new parameter @owner.
This patch provides the basis for later trace events.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch is split from the following one "btrfs: Introduce
extent_io_tree::owner to distinguish different io_trees" from Qu, so the
different changes are not mixed together.
Signed-off-by: David Sterba <dsterba@suse.com>
This patch will add a new member fs_info to extent_io_tree.
This provides the basis for later trace events to distinguish the output
between different btrfs filesystems. While this increases the size of
the structure, we want to know the source of the trace events and
passing the fs_info as an argument to all contexts is not possible.
The selftests are now allowed to set it to NULL as they don't use the
tracepoints.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
inode->i_op is initialized multiple times. Perform it once. This was
left by 4779cc0424 ("Btrfs: get rid of btrfs_symlink_aops").
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"Not a huge amount of changes in this round, the biggest one is that we
finally have Mings multi-page bvec support merged. Apart from that,
this pull request contains:
- Small series that avoids quiescing the queue for sysfs changes that
match what we currently have (Aleksei)
- Series of bcache fixes (via Coly)
- Series of lightnvm fixes (via Mathias)
- NVMe pull request from Christoph. Nothing major, just SPDX/license
cleanups, RR mp policy (Hannes), and little fixes (Bart,
Chaitanya).
- BFQ series (Paolo)
- Save blk-mq cpu -> hw queue mapping, removing a pointer indirection
for the fast path (Jianchao)
- fops->iopoll() added for async IO polling, this is a feature that
the upcoming io_uring interface will use (Christoph, me)
- Partition scan loop fixes (Dongli)
- mtip32xx conversion from managed resource API (Christoph)
- cdrom registration race fix (Guenter)
- MD pull from Song, two minor fixes.
- Various documentation fixes (Marcos)
- Multi-page bvec feature. This brings a lot of nice improvements
with it, like more efficient splitting, larger IOs can be supported
without growing the bvec table size, and so on. (Ming)
- Various little fixes to core and drivers"
* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
block: fix updating bio's front segment size
block: Replace function name in string with __func__
nbd: propagate genlmsg_reply return code
floppy: remove set but not used variable 'q'
null_blk: fix checking for REQ_FUA
block: fix NULL pointer dereference in register_disk
fs: fix guard_bio_eod to check for real EOD errors
blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
block: optimize bvec iteration in bvec_iter_advance
block: introduce mp_bvec_for_each_page() for iterating over page
block: optimize blk_bio_segment_split for single-page bvec
block: optimize __blk_segment_map_sg() for single-page bvec
block: introduce bvec_nth_page()
iomap: wire up the iopoll method
block: add bio_set_polled() helper
block: wire up block device iopoll method
fs: add an iopoll method to struct file_operations
loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
loop: do not print warn message if partition scan is successful
block: bounce: make sure that bvec table is updated
...
We could generate a lot of delayed refs in evict but never have any left
over space from our block rsv to make up for that fact. So reserve some
extra space and give it to the transaction so it can be used to refill
the delayed refs rsv every loop through the truncate path.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The throttle path doesn't take cleaner_delayed_iput_mutex, which means
we could think we're done flushing iputs in the data space reservation
path when we could have a throttler doing an iput. There's no real
reason to serialize the delayed iput flushing, so instead of taking the
cleaner_delayed_iput_mutex whenever we flush the delayed iputs just
replace it with an atomic counter and a waitqueue. This removes the
short (or long depending on how big the inode is) window where we think
there are no more pending iputs when there really are some.
The waiting is killable as it could be indirectly called from user
operations like fallocate or zero-range. Such call sites should handle
the error but otherwise it's not necessary. Eg. flush_space just needs
to attempt to make space by waiting on iputs.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add killable comment and changelog parts ]
Signed-off-by: David Sterba <dsterba@suse.com>
In order to avoid duplicating init code for em there is an additional
label, not_found_em, which is used to only set ->block_start. The only
case when it will be used is if the extent we are adding overlaps with
an existing extent. Make that case more obvious by:
1. Adding a comment hinting at what's going on
2. Assigning EXTENT_MAP_HOLE and directly going to insert.
No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Core btree functions in btrfs generally return 0 when an item is found,
1 in case the sought item cannot be found and <0 when an error happens.
Consolidate the checks for those conditions in one 'if () {} else if ()
{}' construct rather than 2 separate 'if () {}' statements. This
emphasizes that the handling code pertains to a single function. No
functional changes.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
found_type really holds the type of extent and is guaranteed to to have
a value between [0, 2]. The only time it can contain anything different
is if btrfs_lookup_file_extent returned a positive value and the
previous item is different than an extent. Avoid this situation by
simply checking found_key.type rather than assigning the item type to
found_type intermittently. Also make the variable an u8 to reduce stack
usage. No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a comment explaining when ->inode could be NULL and why we always
perform the ->async_delalloc_pages modification.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can never trigger since before calling alloc_delalloc_work we have
called igrab in start_delalloc_inodes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
ihold is supposed to be used when the caller already has a reference to
the inode. In the case of cow_file_range_async this invariants holds,
since the 3 call chains leading to this function all take a reference:
btrfs_writepage <--- does igrab
extent_write_full_page
__extent_writepage
writepage_delalloc
btrfs_run_delalloc_range
cow_file_range_async
extent_write_cache_pages <--- does igrab
__extent_writepage (same callchain as above)
and
submit_compressed_extents <-- already called from async CoW submit path,
which would have done ihold.
extent_write_locked_range
__extent_writepage
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
It's used only once so just inline the call to i_size_read. The
semantics regarding the inode size are not changed, the pages in the
range are locked and i_size cannot change between the time it was set
and used.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We already pass the async_cow struct that holds a reference to the
inode. Exploit this fact and remove the extra inode argument. No
functional changes.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
hole_len is only used if the hole falls within the requested range. Make
that explicitly clear by only assigning in the corresponding branch.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make btrfs_get_extent_fiemap a bit more friendly. First step is to
rename the closely related, yet arbitrary named
range_start/found_end/found variables. They define the delalloc range
that is found in case a real extent wasn't found. Subsequently remove
an unnecessary check for hole_em since it's guaranteed to be set i.e the
check is always true. Top it off by giving all comments a refresh.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformatted a few more comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
This function is a simple wrapper over btrfs_get_extent that returns
either:
a) A real extent in the passed range or
b) Adjusted extent based on whether delalloc bytes are found backing up
a hole.
To support these semantics it doesn't need the page/pg_offset/create
arguments which are passed to btrfs_get_extent in case an extent is to
be created. So simplify the function by removing the unused arguments.
No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since this function is no longer a callback there is no need to have
its first argument obfuscated with a void *. Change it directly to a
pointer to an inode. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The cleaner thread usually takes care of delayed iputs, with the
exception of the btrfs_end_transaction_throttle path. Delaying iputs
means we are potentially delaying the eviction of an inode and it's
respective space. The cleaner thread only gets woken up every 30
seconds, or when we require space. If there are a lot of inodes that
need to be deleted we could induce a serious amount of latency while we
wait for these inodes to be evicted. So instead wakeup the cleaner if
it's not already awake to process any new delayed iputs we add to the
list. If we suddenly need space we will less likely be backed up
behind a bunch of inodes that are waiting to be deleted, and we could
possibly free space before we need to get into the flushing logic which
will save us some latency.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit e73e81b6d0.
This patch causes a few problems:
- adds latency to btrfs_finish_ordered_io
- as btrfs_finish_ordered_io is used for free space cache, generating
more work from btrfs_btree_balance_dirty_nodelay could end up in the
same workque, effectively deadlocking
12260 kworker/u96:16+btrfs-freespace-write D
[<0>] balance_dirty_pages+0x6e6/0x7ad
[<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90
[<0>] btrfs_finish_ordered_io+0x3da/0x770
[<0>] normal_work_helper+0x1c5/0x5a0
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x46/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff
Transaction commit will wait on the freespace cache:
838 btrfs-transacti D
[<0>] btrfs_start_ordered_extent+0x154/0x1e0
[<0>] btrfs_wait_ordered_range+0xbd/0x110
[<0>] __btrfs_wait_cache_io+0x49/0x1a0
[<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0
[<0>] commit_cowonly_roots+0x215/0x2b0
[<0>] btrfs_commit_transaction+0x37e/0x910
[<0>] transaction_kthread+0x14d/0x180
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff
And then writepages ends up waiting on transaction commit:
9520 kworker/u96:13+flush-btrfs-1 D
[<0>] wait_current_trans+0xac/0xe0
[<0>] start_transaction+0x21b/0x4b0
[<0>] cow_file_range_inline+0x10b/0x6b0
[<0>] cow_file_range.isra.69+0x329/0x4a0
[<0>] run_delalloc_range+0x105/0x3c0
[<0>] writepage_delalloc+0x119/0x180
[<0>] __extent_writepage+0x10c/0x390
[<0>] extent_write_cache_pages+0x26f/0x3d0
[<0>] extent_writepages+0x4f/0x80
[<0>] do_writepages+0x17/0x60
[<0>] __writeback_single_inode+0x59/0x690
[<0>] writeback_sb_inodes+0x291/0x4e0
[<0>] __writeback_inodes_wb+0x87/0xb0
[<0>] wb_writeback+0x3bb/0x500
[<0>] wb_workfn+0x40d/0x610
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x1e0/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff
Eventually, we have every process in the system waiting on
balance_dirty_pages(), and nobody is able to make progress on page
writeback.
The original patch tried to fix an OOM condition, that happened on 4.4 but no
success reproducing that on later kernels (4.19 and 4.20). This is more likely
a problem in OOM itself.
Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/
Reported-by: Chris Mason <clm@fb.com>
CC: stable@vger.kernel.org # 4.18+
CC: ethanlien <ethanlien@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The typos accumulate over time so once in a while time they get fixed in
a large patch.
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the error handling block, err holds the return value of either
btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked
since it's introduction with commit fe66a05a06 (Btrfs: improve error
handling for btrfs_insert_dir_item callers) in 2012.
If the error handling in the error handling fails, there's not much left
to do and the abort either happened earlier in the callees or is
necessary here.
So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort
the transaction, but still return the original code of the failure
stored in 'ret' as this will be reported to the user.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a bunch of magic to make sure we're throttling delayed refs when
truncating a file. Now that we have a delayed refs rsv and a mechanism
for refilling that reserve simply use that instead of all of this magic.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now with the delayed_refs_rsv we can now know exactly how much pending
delayed refs space we need. This means we can drastically simplify
btrfs_check_space_for_delayed_refs by simply checking how much space we
have reserved for the global rsv (which acts as a spill over buffer) and
the delayed refs rsv. If our total size is beyond that amount then we
know it's time to commit the transaction and stop any more delayed refs
from being generated.
With the introduction of dealyed_refs_rsv infrastructure, namely
btrfs_update_delayed_refs_rsv we now know exactly how much pending
delayed refs space is required.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When using a 'var & (PAGE_SIZE - 1)' construct one is checking for a page
alignment and thus should use the PAGE_ALIGNED() macro instead of
open-coding it.
Convert all open-coded occurrences of PAGE_ALIGNED().
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Constructs like 'var & (PAGE_SIZE - 1)' or 'var & ~PAGE_MASK' can denote an
offset into a page.
So replace them by the offset_in_page() macro instead of open-coding it if
they're not used as an alignment check.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Running btrfs/124 in a loop hung up on me sporadically with the
following call trace:
btrfs D 0 5760 5324 0x00000000
Call Trace:
? __schedule+0x243/0x800
schedule+0x33/0x90
btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs]
? wait_woken+0xa0/0xa0
btrfs_wait_ordered_range+0xbb/0x100 [btrfs]
btrfs_relocate_block_group+0x1ff/0x230 [btrfs]
btrfs_relocate_chunk+0x49/0x100 [btrfs]
btrfs_balance+0xbeb/0x1740 [btrfs]
btrfs_ioctl_balance+0x2ee/0x380 [btrfs]
btrfs_ioctl+0x1691/0x3110 [btrfs]
? lockdep_hardirqs_on+0xed/0x180
? __handle_mm_fault+0x8e7/0xfb0
? _raw_spin_unlock+0x24/0x30
? __handle_mm_fault+0x8e7/0xfb0
? do_vfs_ioctl+0xa5/0x6e0
? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
do_vfs_ioctl+0xa5/0x6e0
? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
ksys_ioctl+0x3a/0x70
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x60/0x1b0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
This happens because during page writeback it's valid for
writepage_delalloc to instantiate a delalloc range which doesn't belong
to the page currently being written back.
The reason this case is valid is due to find_lock_delalloc_range
returning any available range after the passed delalloc_start and
ignoring whether the page under writeback is within that range.
In turn ordered extents (OE) are always created for the returned range
from find_lock_delalloc_range. If, however, a failure occurs while OE
are being created then the clean up code in btrfs_cleanup_ordered_extents
will be called.
Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider
the case of such 'foreign' range being processed and instead it always
assumes that the range OE are created for belongs to the page. This
leads to the first page of such foregin range to not be cleaned up since
it's deliberately missed and skipped by the current cleaning up code.
Fix this by correctly checking whether the current page belongs to the
range being instantiated and if so adjsut the range parameters passed
for cleaning up. If it doesn't, then just clean the whole OE range
directly.
Fixes: 524272607e ("btrfs: Handle delalloc error correctly to avoid ordered extent hang")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The test case btrfs/001 with inode_cache mount option will encounter the
following warning:
WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs]
CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs]
Call Trace:
? free_extent_buffer+0x46/0x90 [btrfs]
run_delalloc_nocow+0x455/0x900 [btrfs]
btrfs_run_delalloc_range+0x1a7/0x360 [btrfs]
writepage_delalloc+0xf9/0x150 [btrfs]
__extent_writepage+0x125/0x3e0 [btrfs]
extent_write_cache_pages+0x1b6/0x3e0 [btrfs]
? __wake_up_common_lock+0x63/0xc0
extent_writepages+0x50/0x80 [btrfs]
do_writepages+0x41/0xd0
? __filemap_fdatawrite_range+0x9e/0xf0
__filemap_fdatawrite_range+0xbe/0xf0
btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
__btrfs_write_out_cache+0x42c/0x480 [btrfs]
btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
btrfs_save_ino_cache+0x551/0x660 [btrfs]
commit_fs_roots+0xc5/0x190 [btrfs]
btrfs_commit_transaction+0x2bf/0x8d0 [btrfs]
btrfs_mksubvol+0x48d/0x4d0 [btrfs]
btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs]
btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs]
btrfs_ioctl+0x123f/0x3030 [btrfs]
The file extent generation of the free space inode is equal to the last
snapshot of the file root, so the inode will be passed to cow_file_rage.
But the inode was created and its extents were preallocated in
btrfs_save_ino_cache, there are no cow copies on disk.
The preallocated extent is not yet in the extent tree, and
btrfs_cross_ref_exist will ignore the -ENOENT returned by
check_committed_ref, so we can directly write the inode to the disk.
Fixes: 78d4295b1e ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path")
CC: stable@vger.kernel.org # 4.18+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The log tree has a long standing problem that when a file is fsync'ed we
only check for new ancestors, created in the current transaction, by
following only the hard link for which the fsync was issued. We follow the
ancestors using the VFS' dget_parent() API. This means that if we create a
new link for a file in a directory that is new (or in an any other new
ancestor directory) and then fsync the file using an old hard link, we end
up not logging the new ancestor, and on log replay that new hard link and
ancestor do not exist. In some cases, involving renames, the file will not
exist at all.
Example:
mkfs.btrfs -f /dev/sdb
mount /dev/sdb /mnt
mkdir /mnt/A
touch /mnt/foo
ln /mnt/foo /mnt/A/bar
xfs_io -c fsync /mnt/foo
<power failure>
In this example after log replay only the hard link named 'foo' exists
and directory A does not exist, which is unexpected. In other major linux
filesystems, such as ext4, xfs and f2fs for example, both hard links exist
and so does directory A after mounting again the filesystem.
Checking if any new ancestors are new and need to be logged was added in
2009 by commit 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes"),
however only for the ancestors of the hard link (dentry) for which the
fsync was issued, instead of checking for all ancestors for all of the
inode's hard links.
So fix this by tracking the id of the last transaction where a hard link
was created for an inode and then on fsync fallback to a full transaction
commit when an inode has more than one hard link and at least one new hard
link was created in the current transaction. This is the simplest solution
since this is not a common use case (adding frequently hard links for
which there's an ancestor created in the current transaction and then
fsync the file). In case it ever becomes a common use case, a solution
that consists of iterating the fs/subvol btree for each hard link and
check if any ancestor is new, could be implemented.
This solves many unexpected scenarios reported by Jayashree Mohan and
Vijay Chidambaram, and for which there is a new test case for fstests
under review.
Fixes: 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Reported-by: Vijay Chidambaram <vvijay03@gmail.com>
Reported-by: Jayashree Mohan <jayashree2912@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function really checks whether adding more data to the bio will
straddle a stripe/chunk. So first let's give it a more appropraite name
- btrfs_bio_fits_in_stripe. Secondly, the offset parameter was never
used to just remove it. Thirdly, pages are submitted to either btree or
data inodes so it's guaranteed that tree->ops is set so replace the
check with an ASSERT. Finally, document the parameters of the function.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For data inodes this hook does nothing but to return -EAGAIN which is
used to signal to the endio routines that this bio belongs to a data
inode. If this is the case the actual retrying is handled by
bio_readpage_error. Alternatively, if this bio belongs to the btree
inode then btree_io_failed_hook just does some cleanup and doesn't retry
anything.
This patch simplifies the code flow by eliminating
readpage_io_failed_hook and instead open-coding btree_io_failed_hook in
end_bio_extent_readpage. Also eliminate some needless checks since IO is
always performed on either data inode or btree inode, both of which are
guaranteed to have their extent_io_tree::ops set.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The end_io callback implemented as btrfs_io_bio_endio_readpage only
calls kfree. Also the callback is set only in case the csum buffer is
allocated and not pointing to the inline buffer. We can use that
information to drop the indirection and call a helper that will free the
csums only in the right case.
This shrinks struct btrfs_io_bio by 8 bytes.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
The async_cow::root is used to propagate fs_info to async_cow_submit.
We can't use inode to reach it because it could become NULL after
write without compression in async_cow_start.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
There's one caller and its code is simple, we can open code it in
run_one_async_done. The errors are passed through bio.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Up to commit 32955c5422 ("btrfs: switch to discard_new_inode()") the
drop_on_err variable in btrfs_mkdir() was used to check whether the
inode had to be dropped via iput().
After commit 32955c5422 ("btrfs: switch to discard_new_inode()")
discard_new_inode() is called when err is set and inode is non NULL.
Therefore drop_on_err is not used anymore and thus causes a warning when
building with -Wunused-but-set-variable.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Snapshot is expected to be fast. But if there are writers steadily
creating dirty pages in our subvolume, the snapshot may take a very long
time to complete. To fix the problem, we use tagged writepage for
snapshot flusher as we do in the generic write_cache_pages(), so we can
omit pages dirtied after the snapshot command.
This does not change the semantics regarding which data get to the
snapshot, if there are pages being dirtied during the snapshotting
operation. There's a sync called before snapshot is taken in old/new
case, any IO in flight just after that may be in the snapshot but this
depends on other system effects that might still sync the IO.
We do a simple snapshot speed test on a Intel D-1531 box:
fio --ioengine=libaio --iodepth=32 --bs=4k --rw=write --size=64G
--direct=0 --thread=1 --numjobs=1 --time_based --runtime=120
--filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio
original: 1m58sec
patched: 6.54sec
This is the best case for this patch since for a sequential write case,
we omit nearly all pages dirtied after the snapshot command.
For a multi writers, random write test:
fio --ioengine=libaio --iodepth=32 --bs=4k --rw=randwrite --size=64G
--direct=0 --thread=1 --numjobs=4 --time_based --runtime=120
--filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio
original: 15.83sec
patched: 10.35sec
The improvement is smaller compared to the sequential write case,
since we omit only half of the pages dirtied after snapshot command.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Ethan Lien <ethanlien@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This parameter was never used, yet was part of the interface of the
function ever since its introduction as extent_io_ops::writepage_end_io_hook
in e6dcd2dc9c ("Btrfs: New data=ordered implementation"). Now that
NULL is passed everywhere as a value for this parameter let's remove it
for good. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs has not allowed swap files since commit 35054394c4 ("Btrfs: stop
providing a bmap operation to avoid swapfile corruptions"). However, now
that the proper restrictions are in place, Btrfs can support swap files
through the swap file a_ops, similar to iomap in commit 67482129cd
("iomap: add a swapfile activation function").
For Btrfs, activation needs to make sure that the file can be used as a
swap file, which currently means that it must be fully allocated as
NOCOW with no compression on one device. It must also do the proper
tracking so that ioctls will not interfere with the swap file.
Deactivation clears this tracking.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the counterpart to merge_extent_hook, similarly, it's used only
for data/freespace inodes so let's remove it, rename it and call it
directly where necessary. No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This callback is used only for data and free space inodes. Such inodes
are guaranteed to have their extent_io_tree::private_data set to the
inode struct. Exploit this fact to directly call the function. Also give
it a more descriptive name. No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the counterpart to ex-set_bit_hook (now btrfs_set_delalloc_extent),
similar to what was done before remove clear_bit_hook and rename the
function. No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This callback is used to properly account delalloc extents for data
inodes (ordinary file inodes and freespace v1 inodes). Those can be
easily identified since they have their extent_io trees ->private_data
member point to the inode. Let's exploit this fact to remove the
needless indirection through extent_io_hooks and directly call the
function. Also give the function a name which reflects its purpose -
btrfs_set_delalloc_extent.
This patch also modified test_find_delalloc so that the extent_io_tree
used for testing doesn't have its ->private_data set which would have
caused a crash in btrfs_set_delalloc_extent due to the btrfs_inode->root
member not being initialised. The old version of the code also didn't
call set_bit_hook since the extent_io ops weren't set for the inode. No
functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This callback was only used in debug builds by btrfs_leak_debug_check.
A better approach is to move its implementation in
btrfs_leak_debug_check and ensure the latter is only executed for extent
tree which have ->private_data set i.e. relate to a data node and not
the btree one. No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This callback is ony ever called for data page writeout so there is no
need to actually abstract it via extent_io_ops. Lets just export it,
remove the definition of the callback and call it directly in the
functions that invoke the callback. Also rename the function to
btrfs_writepage_endio_finish_ordered since what it really does is
account finished io in the ordered extent data structures. No
functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This hook is called only from __extent_writepage_io which is already
called only from the data page writeout path. So there is no need to
make an indirect call via extent_io_ops. This patch just removes the
callback definition, exports the callback function and calls it directly
at the only call site. Also give the function a more descriptive name.
No functional changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo