There will be a second mb_cache instance that tracks ea_inodes. Make
existing names more explicit so that it is clear that they refer to
xattr block cache.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Make names more generic so that mbcache usage is not limited to
block sharing. In a subsequent patch in the series
("ext4: xattr inode deduplication"), we start using the mbcache code
for sharing xattr inodes. With that patch, old mb_cache_entry.e_block
field could be holding either a block number or an inode number.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since this is a xattr specific data structure it is cleaner to keep it in
xattr header file.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tracking struct inode * rather than the inode number eliminates the
repeated ext4_xattr_inode_iget() call later. The second call cannot
fail in practice but still requires explanation when it wants to ignore
the return value. Avoid the trouble and make things simple.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Both ext4_set_acl() and ext4_set_context() need to be made aware of
ea_inode feature when it comes to credits calculation.
Also add a sufficient credits check in ext4_xattr_set_handle() right
after xattr write lock is grabbed. Original credits calculation is done
outside the lock so there is a possiblity that the initially calculated
credits are not sufficient anymore.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In a few places the function returns without trying to pass the actual
error code to the caller. Fix those.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When value size is <= EXT4_XATTR_MIN_LARGE_EA_SIZE(), and it
doesn't fit in either inline or xattr block, a second try is made to
store it in an external inode while storing the entry itself in inline
area. There should also be an attempt to store the entry in xattr block.
This patch adds a retry loop to do that. It also makes the caller the
sole decider on whether to store a value in an external inode.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When there is no space for a value in xattr block, it may be stored
in an xattr inode even if the value length is less than
EXT4_XATTR_MIN_LARGE_EA_SIZE(). So the current assumption in credits
calculation is wrong.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When a xattr entry refers to an external inode, the value data is not
available in the inline area so we should not attempt to read it using
value offset.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When moving xattr entries from inline area to a xattr block, entries
that refer to external xattr inodes need special handling because
value data is not available in the inline area but rather should be
read from its external inode.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_xattr_make_inode_space() is interested in calculating the inline
space used in an inode. When a xattr entry refers to an external inode
the value size indicates the external inode size, not the value size in
the inline area. Change the function to take this into account.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_xattr_value_same() is used as a quick optimization in case the new
xattr value is identical to the previous value. When xattr value is
stored in a xattr inode the check becomes expensive so it is better to
just assume that they are not equal.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Two places in code missed converting xattr inode number using
le32_to_cpu().
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The input and output values of *size parameter are equal on successful
return from ext4_xattr_inode_get(). On error return, the callers ignore
the output value so there is no need to update it.
Also check for NULL return from ext4_bread(). If the actual xattr inode
size happens to be smaller than the expected size, ext4_bread() may
return NULL which would indicate data corruption.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In general, kernel functions indicate success/failure through their return
values. This function returns the status as an output parameter and reserves
the return value for the inode. Make it follow the general convention.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
EXT4_XATTR_MAX_LARGE_EA_SIZE definition in ext4 is currently unused.
Besides, vfs enforces its own 64k limit which makes the 1MB limit in
ext4 redundant. Remove it.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The ref count on ea_inode is incremented by
ext4_xattr_inode_orphan_add() which is supposed to be decremented by
ext4_xattr_inode_array_free(). The decrement is conditioned on whether
the ea_inode is currently on the orphan list. However, the orphan list
addition only happens when journaling is enabled. In non-journaled case,r
we fail to release the ref count causing an error message like below.
"VFS: Busy inodes after unmount of sdb. Self-destruct in 5 seconds.
Have a nice day..."
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ea_inode contents are treated as metadata, that's why it is journaled
during initial writes. Failing to call revoke during freeing could cause
user data to be overwritten with original ea_inode contents during journal
replay.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Quota charging is based on the ownership of the inode. Currently, the
xattr inode owner is set to the caller which may be different from the
parent inode owner. This is inconsistent with how quota is charged for
xattr block and regular data block writes.
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We don't need acls on xattr inodes because they are not directly
accessible from user mode.
Besides lockdep complains about recursive locking of xattr_sem as seen
below.
=============================================
[ INFO: possible recursive locking detected ]
4.11.0-rc8+ #402 Not tainted
---------------------------------------------
python/1894 is trying to acquire lock:
(&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270
but task is already holding lock:
(&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ei->xattr_sem);
lock(&ei->xattr_sem);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by python/1894:
#0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50
#1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0
#2: (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0
stack backtrace:
CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x67/0x99
__lock_acquire+0x5f3/0x1830
lock_acquire+0xb5/0x1d0
down_read+0x2f/0x60
ext4_xattr_get+0x66/0x270
ext4_get_acl+0x43/0x1e0
get_acl+0x72/0xf0
posix_acl_create+0x5e/0x170
ext4_init_acl+0x21/0xc0
__ext4_new_inode+0xffd/0x16b0
ext4_xattr_set_entry+0x5ea/0xb70
ext4_xattr_block_set+0x1b5/0x970
ext4_xattr_set_handle+0x351/0x5d0
ext4_xattr_set+0x124/0x180
ext4_xattr_user_set+0x34/0x40
__vfs_setxattr+0x66/0x80
__vfs_setxattr_noperm+0x69/0x1c0
vfs_setxattr+0xa2/0xb0
setxattr+0x129/0x160
path_setxattr+0x87/0xb0
SyS_setxattr+0xf/0x20
entry_SYSCALL_64_fastpath+0x18/0xad
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Setting a large xattr value may require writing the attribute contents
to an external inode. In this case we may need to lock the xattr inode
along with the parent inode. This doesn't pose a deadlock risk because
xattr inodes are not directly visible to the user and their access is
restricted.
Assign a lockdep subclass to xattr inode's lock.
============================================
WARNING: possible recursive locking detected
4.12.0-rc1+ #740 Not tainted
--------------------------------------------
python/1822 is trying to acquire lock:
(&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff804912ca>] ext4_xattr_set_entry+0x65a/0x7b0
but task is already holding lock:
(&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803d6687>] vfs_setxattr+0x57/0xb0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&sb->s_type->i_mutex_key#15);
lock(&sb->s_type->i_mutex_key#15);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by python/1822:
#0: (sb_writers#10){.+.+.+}, at: [<ffffffff803d0eef>] mnt_want_write+0x1f/0x50
#1: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803d6687>] vfs_setxattr+0x57/0xb0
#2: (jbd2_handle){.+.+..}, at: [<ffffffff80493f40>] start_this_handle+0xf0/0x420
#3: (&ei->xattr_sem){++++..}, at: [<ffffffff804920ba>] ext4_xattr_set_handle+0x9a/0x4f0
stack backtrace:
CPU: 0 PID: 1822 Comm: python Not tainted 4.12.0-rc1+ #740
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x67/0x9e
__lock_acquire+0x5f3/0x1750
lock_acquire+0xb5/0x1d0
down_write+0x2c/0x60
ext4_xattr_set_entry+0x65a/0x7b0
ext4_xattr_block_set+0x1b2/0x9b0
ext4_xattr_set_handle+0x322/0x4f0
ext4_xattr_set+0x144/0x1a0
ext4_xattr_user_set+0x34/0x40
__vfs_setxattr+0x66/0x80
__vfs_setxattr_noperm+0x69/0x1c0
vfs_setxattr+0xa2/0xb0
setxattr+0x12e/0x150
path_setxattr+0x87/0xb0
SyS_setxattr+0xf/0x20
entry_SYSCALL_64_fastpath+0x18/0xad
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.
If the size of an xattr value is larger than will fit in a single
external block, then the xattr value will be saved into the body
of an external xattr inode.
The also helps support a larger number of xattr, since only the headers
will be stored in the in-inode space or the single external block.
The inode is referenced from the xattr header via "e_value_inum",
which was formerly "e_value_block", but that field was never used.
The e_value_size still contains the xattr size so that listing
xattrs does not need to look up the inode if the data is not accessed.
struct ext4_xattr_entry {
__u8 e_name_len; /* length of name */
__u8 e_name_index; /* attribute name index */
__le16 e_value_offs; /* offset in disk block of value */
__le32 e_value_inum; /* inode in which value is stored */
__le32 e_value_size; /* size of attribute value */
__le32 e_hash; /* hash value of name and value */
char e_name[0]; /* attribute name */
};
The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
holds a back-reference to the owning inode in its i_mtime field,
allowing the ext4/e2fsck to verify the correct inode is accessed.
[ Applied fix by Dan Carpenter to avoid freeing an ERR_PTR. ]
Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424
Signed-off-by: Kalpak Shah <kalpak.shah@sun.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
This INCOMPAT_LARGEDIR feature allows larger directories to be created
in ldiskfs, both with directory sizes over 2GB and and a maximum htree
depth of 3 instead of the current limit of 2. These features are needed
in order to exceed the current limit of approximately 10M entries in a
single directory.
This patch was originally written by Yang Sheng to support the Lustre server.
[ Bumped the credits needed to update an indexed directory -- tytso ]
Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Signed-off-by: Artem Blagodarenko <artem.blagodarenko@seagate.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Currently, extent manipulation operations such as hole punch, range
zeroing, or extent shifting do not record the fact that file data has
changed and thus fdatasync(2) has a work to do. As a result if we crash
e.g. after a punch hole and fdatasync, user can still possibly see the
punched out data after journal replay. Test generic/392 fails due to
these problems.
Fix the problem by properly marking that file data has changed in these
operations.
CC: stable@vger.kernel.org
Fixes: a4bb6b64e3
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
mpage_submit_page() can race with another process growing i_size and
writing data via mmap to the written-back page. As mpage_submit_page()
samples i_size too early, it may happen that ext4_bio_write_page()
zeroes out too large tail of the page and thus corrupts user data.
Fix the problem by sampling i_size only after the page has been
write-protected in page tables by clear_page_dirty_for_io() call.
Reported-by: Michael Zimmer <michael@swarm64.com>
CC: stable@vger.kernel.org
Fixes: cb20d51883
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When ext4_map_blocks() is called with EXT4_GET_BLOCKS_ZERO to zero-out
allocated blocks and these blocks are actually converted from unwritten
extent the following race can happen:
CPU0 CPU1
page fault page fault
... ...
ext4_map_blocks()
ext4_ext_map_blocks()
ext4_ext_handle_unwritten_extents()
ext4_ext_convert_to_initialized()
- zero out converted extent
ext4_zeroout_es()
- inserts extent as initialized in status tree
ext4_map_blocks()
ext4_es_lookup_extent()
- finds initialized extent
write data
ext4_issue_zeroout()
- zeroes out new extent overwriting data
This problem can be reproduced by generic/340 for the fallocated case
for the last block in the file.
Fix the problem by avoiding zeroing out the area we are mapping with
ext4_map_blocks() in ext4_ext_convert_to_initialized(). It is pointless
to zero out this area in the first place as the caller asked us to
convert the area to initialized because he is just going to write data
there before the transaction finishes. To achieve this we delete the
special case of zeroing out full extent as that will be handled by the
cases below zeroing only the part of the extent that needs it. We also
instruct ext4_split_extent() that the middle of extent being split
contains data so that ext4_split_extent_at() cannot zero out full extent
in case of ENOSPC.
CC: stable@vger.kernel.org
Fixes: 12735f8819
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr
block when new references are made. However if dquot_initialize() hasn't
been called on an inode, request for charging is effectively ignored
because ext4_inode_info->i_dquot is not initialized yet.
Add dquot_initialize() to call paths that lead to ext4_xattr_block_set().
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Currently we don't allow direct I/O on encrypted regular files, so in
such cases we return 0 early in ext4_direct_IO(). There was also an
additional BUG_ON() check in ext4_direct_IO_write(), but it can never be
hit because of the earlier check for the exact same condition in
ext4_direct_IO(). There was also no matching check on the read path,
which made the write path specific check seem very ad-hoc.
Just remove the unnecessary BUG_ON().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: David Gstir <david@sigma-star.at>
Reviewed-by: Jan Kara <jack@suse.cz>
Now that we are passing a struct ext4_filename, we do not need to pass
around the original struct qstr too.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
The 'lend' argument of filemap_write_and_wait_range() is inclusive, so
we need to subtract 1 from pos + count.
Note that 'count' is guaranteed to be nonzero since
ext4_file_read_iter() returns early when given a 0 count.
Fixes: 16c5468859 ("ext4: Allow parallel DIO reads")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
ext4_find_unwritten_pgoff() is used to search for offset of hole or
data in page range [index, end] (both inclusive), and the max number
of pages to search should be at least one, if end == index.
Otherwise the only page is missed and no hole or data is found,
which is not correct.
When block size is smaller than page size, this can be demonstrated
by preallocating a file with size smaller than page size and writing
data to the last block. E.g. run this xfs_io command on a 1k block
size ext4 on x86_64 host.
# xfs_io -fc "falloc 0 3k" -c "pwrite 2k 1k" \
-c "seek -d 0" /mnt/ext4/testfile
wrote 1024/1024 bytes at offset 2048
1 KiB, 1 ops; 0.0000 sec (42.459 MiB/sec and 43478.2609 ops/sec)
Whence Result
DATA EOF
Data at offset 2k was missed, and lseek(2) returned ENXIO.
This is unconvered by generic/285 subtest 07 and 08 on ppc64 host,
where pagesize is 64k. Because a recent change to generic/285
reduced the preallocated file size to smaller than 64k.
Signed-off-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
ext4_expand_extra_isize() should clear only space between old and new
size.
Fixes: 6dd4ee7cab # v2.6.23
Cc: stable@vger.kernel.org
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
I've got another report about breaking ext4 by ENOMEM error returned from
ext4_mb_load_buddy() caused by memory shortage in memory cgroup.
This time inside ext4_discard_preallocations().
This patch replaces ext4_error() with ext4_warning() where errors returned
from ext4_mb_load_buddy() are not fatal and handled by caller:
* ext4_mb_discard_group_preallocations() - called before generating ENOSPC,
we'll try to discard other group or return ENOSPC into user-space.
* ext4_trim_all_free() - just stop trimming and return ENOMEM from ioctl.
Some callers cannot handle errors, thus __GFP_NOFAIL is used for them:
* ext4_discard_preallocations()
* ext4_mb_discard_lg_preallocations()
Fixes: adb7ef600c ("ext4: use __GFP_NOFAIL in ext4_free_blocks()")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
There is an off-by-one error in loop termination conditions in
ext4_find_unwritten_pgoff() since 'end' may index a page beyond end of
desired range if 'endoff' is page aligned. It doesn't have any visible
effects but still it is good to fix it.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, SEEK_HOLE implementation in ext4 may both return that there's
a hole at some offset although that offset already has data and skip
some holes during a search for the next hole. The first problem is
demostrated by:
xfs_io -c "falloc 0 256k" -c "pwrite 0 56k" -c "seek -h 0" file
wrote 57344/57344 bytes at offset 0
56 KiB, 14 ops; 0.0000 sec (2.054 GiB/sec and 538461.5385 ops/sec)
Whence Result
HOLE 0
Where we can see that SEEK_HOLE wrongly returned offset 0 as containing
a hole although we have written data there. The second problem can be
demonstrated by:
xfs_io -c "falloc 0 256k" -c "pwrite 0 56k" -c "pwrite 128k 8k"
-c "seek -h 0" file
wrote 57344/57344 bytes at offset 0
56 KiB, 14 ops; 0.0000 sec (1.978 GiB/sec and 518518.5185 ops/sec)
wrote 8192/8192 bytes at offset 131072
8 KiB, 2 ops; 0.0000 sec (2 GiB/sec and 500000.0000 ops/sec)
Whence Result
HOLE 139264
Where we can see that hole at offsets 56k..128k has been ignored by the
SEEK_HOLE call.
The underlying problem is in the ext4_find_unwritten_pgoff() which is
just buggy. In some cases it fails to update returned offset when it
finds a hole (when no pages are found or when the first found page has
higher index than expected), in some cases conditions for detecting hole
are just missing (we fail to detect a situation where indices of
returned pages are not contiguous).
Fix ext4_find_unwritten_pgoff() to properly detect non-contiguous page
indices and also handle all cases where we got less pages then expected
in one place and handle it properly there.
CC: stable@vger.kernel.org
Fixes: c8c0df241c
CC: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When a transaction starts, start_this_handle() saves current
PF_MEMALLOC_NOFS value so that it can be restored at journal stop time.
Journal restart is a special case that calls start_this_handle() without
stopping the transaction. start_this_handle() isn't aware that the
original value is already stored so it overwrites it with current value.
For instance, a call sequence like below leaves PF_MEMALLOC_NOFS flag set
at the end:
jbd2_journal_start()
jbd2__journal_restart()
jbd2_journal_stop()
Make jbd2__journal_restart() restore the original value before calling
start_this_handle().
Fixes: 81378da64d ("jbd2: mark the transaction context with the scope GFP_NOFS context")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Quota files have special ranking of i_data_sem lock. We inform lockdep
about it when turning on quotas however when turning quotas off, we
don't clear the lockdep subclass from i_data_sem lock and thus when the
inode gets later reused for a normal file or directory, lockdep gets
confused and complains about possible deadlocks. Fix the problem by
resetting lockdep subclass of i_data_sem on quota off.
Cc: stable@vger.kernel.org
Fixes: daf647d2dd
Reported-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The code to fetch a 64-bit value from user space was entirely buggered,
and has been since the code was merged in early 2016 in commit
b2f680380d ("x86/mm/32: Add support for 64-bit __get_user() on 32-bit
kernels").
Happily the buggered routine is almost certainly entirely unused, since
the normal way to access user space memory is just with the non-inlined
"get_user()", and the inlined version didn't even historically exist.
The normal "get_user()" case is handled by external hand-written asm in
arch/x86/lib/getuser.S that doesn't have either of these issues.
There were two independent bugs in __get_user_asm_u64():
- it still did the STAC/CLAC user space access marking, even though
that is now done by the wrapper macros, see commit 11f1a4b975
("x86: reorganize SMAP handling in user space accesses").
This didn't result in a semantic error, it just means that the
inlined optimized version was hugely less efficient than the
allegedly slower standard version, since the CLAC/STAC overhead is
quite high on modern Intel CPU's.
- the double register %eax/%edx was marked as an output, but the %eax
part of it was touched early in the asm, and could thus clobber other
inputs to the asm that gcc didn't expect it to touch.
In particular, that meant that the generated code could look like
this:
mov (%eax),%eax
mov 0x4(%eax),%edx
where the load of %edx obviously was _supposed_ to be from the 32-bit
word that followed the source of %eax, but because %eax was
overwritten by the first instruction, the source of %edx was
basically random garbage.
The fixes are trivial: remove the extraneous STAC/CLAC entries, and mark
the 64-bit output as early-clobber to let gcc know that no inputs should
alias with the output register.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@kernel.org # v4.8+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al noticed that unsafe_put_user() had type problems, and fixed them in
commit a7cc722fff ("fix unsafe_put_user()"), which made me look more
at those functions.
It turns out that unsafe_get_user() had a type issue too: it limited the
largest size of the type it could handle to "unsigned long". Which is
fine with the current users, but doesn't match our existing normal
get_user() semantics, which can also handle "u64" even when that does
not fit in a long.
While at it, also clean up the type cast in unsafe_put_user(). We
actually want to just make it an assignment to the expected type of the
pointer, because we actually do want warnings from types that don't
convert silently. And it makes the code more readable by not having
that one very long and complex line.
[ This patch might become stable material if we ever end up back-porting
any new users of the unsafe uaccess code, but as things stand now this
doesn't matter for any current existing uses. ]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc uaccess fixes from Al Viro:
"Fix for unsafe_put_user() (no callers currently in mainline, but
anyone starting to use it will step into that) + alpha osf_wait4()
infoleak fix"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
osf_wait4(): fix infoleak
fix unsafe_put_user()
Pull scheduler fix from Thomas Gleixner:
"A single scheduler fix:
Prevent idle task from ever being preempted. That makes sure that
synchronize_rcu_tasks() which is ignoring idle task does not pretend
that no task is stuck in preempted state. If that happens and idle was
preempted on a ftrace trampoline the machine crashes due to
inconsistent state"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Call __schedule() from do_idle() without enabling preemption
Pull irq fixes from Thomas Gleixner:
"A set of small fixes for the irq subsystem:
- Cure a data ordering problem with chained interrupts
- Three small fixlets for the mbigen irq chip"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Fix chained interrupt data ordering
irqchip/mbigen: Fix the clear register offset calculation
irqchip/mbigen: Fix potential NULL dereferencing
irqchip/mbigen: Fix memory mapping code
__put_user_size() relies upon its first argument having the same type as what
the second one points to; the only other user makes sure of that and
unsafe_put_user() should do the same.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
when deleting an instance. It also creates a selftest that triggers that bug.
Fix the delayed optimization happening after kprobes boot up self tests
being removed by freeing of init memory.
Comment kprobes on why the delay optimization is not a problem for removal
of modules, to keep other developers from searching that riddle.
Fix another rcu isn't watching in stack trace tracing.
Naveen N. Rao (4):
ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()
ftrace/instances: Clear function triggers when removing instances
selftests/ftrace: Fix bashisms
selftests/ftrace: Add test to remove instance with active event triggers
Steven Rostedt (1):
tracing: Move postpone selftests to core from early_initcall
Steven Rostedt (VMware) (3):
ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
kprobes: Document how optimized kprobes are removed from module unload
tracing: Make sure RCU is watching before calling a stack trace
Thomas Gleixner (1):
tracing/kprobes: Enforce kprobes teardown after testing
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Merge tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix a bug caused by not cleaning up the new instance unique triggers
when deleting an instance. It also creates a selftest that triggers
that bug.
- Fix the delayed optimization happening after kprobes boot up self
tests being removed by freeing of init memory.
- Comment kprobes on why the delay optimization is not a problem for
removal of modules, to keep other developers from searching that
riddle.
- Fix another case of rcu not watching in stack trace tracing.
* tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Make sure RCU is watching before calling a stack trace
kprobes: Document how optimized kprobes are removed from module unload
selftests/ftrace: Add test to remove instance with active event triggers
selftests/ftrace: Fix bashisms
ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
ftrace/instances: Clear function triggers when removing instances
ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()
tracing/kprobes: Enforce kprobes teardown after testing
tracing: Move postpone selftests to core from early_initcall
Pull block fixes from Jens Axboe:
"A small collection of fixes that should go into this cycle.
- a pull request from Christoph for NVMe, which ended up being
manually applied to avoid pulling in newer bits in master. Mostly
fibre channel fixes from James, but also a few fixes from Jon and
Vijay
- a pull request from Konrad, with just a single fix for xen-blkback
from Gustavo.
- a fuseblk bdi fix from Jan, fixing a regression in this series with
the dynamic backing devices.
- a blktrace fix from Shaohua, replacing sscanf() with kstrtoull().
- a request leak fix for drbd from Lars, fixing a regression in the
last series with the kref changes. This will go to stable as well"
* 'for-linus' of git://git.kernel.dk/linux-block:
nvmet: release the sq ref on rdma read errors
nvmet-fc: remove target cpu scheduling flag
nvme-fc: stop queues on error detection
nvme-fc: require target or discovery role for fc-nvme targets
nvme-fc: correct port role bits
nvme: unmap CMB and remove sysfs file in reset path
blktrace: fix integer parse
fuseblk: Fix warning in super_setup_bdi_name()
block: xen-blkback: add null check to avoid null pointer dereference
drbd: fix request leak introduced by locking/atomic, kref: Kill kref_sub()
On rdma read errors, release the sq ref that was taken
when the req was initialized. This avoids a hang in
nvmet_sq_destroy() when the queue is being freed.
Signed-off-by: Vijay Immanuel <vijayi@attalasystems.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Tahsin Erdogan