Filipe Manana [Wed, 30 Mar 2016 22:37:21 +0000 (23:37 +0100)]
Btrfs: fix file/data loss caused by fsync after rename and new inode
If we rename an inode A (be it a file or a directory), create a new
inode B with the old name of inode A and under the same parent directory,
fsync inode B and then power fail, at log tree replay time we end up
removing inode A completely. If inode A is a directory then all its files
are gone too.
Example scenarios where this happens:
This is reproducible with the following steps, taken from a couple of
test cases written for fstests which are going to be submitted upstream
soon:
The next time the fs is mounted, log tree replay happens and
the directory "y" does not exist nor do the files "foo" and
"bar" exist anywhere (neither in "y" nor in "x", nor the root
nor anywhere).
The next time the fs is mounted, log tree replay happens and the
file "bar" does not exists anymore. A file with the name "foo"
exists and it matches the second file we created.
Another related problem that does not involve file/data loss is when a
new inode is created with the name of a deleted snapshot and we fsync it:
The next time the fs is mounted the log replay procedure fails because
it attempts to delete the snapshot entry (which has dir item key type
of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry,
resulting in the following error that causes mount to fail:
Fix this by forcing a transaction commit when such cases happen.
This means we check in the commit root of the subvolume tree if there
was any other inode with the same reference when the inode we are
fsync'ing is a new inode (created in the current transaction).
Test cases for fstests, covering all the scenarios given above, were
submitted upstream for fstests:
* fstests: generic test for fsync after renaming directory
https://patchwork.kernel.org/patch/8694281/
* fstests: generic test for fsync after renaming file
https://patchwork.kernel.org/patch/8694301/
* fstests: add btrfs test for fsync after snapshot deletion
https://patchwork.kernel.org/patch/8670671/
Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 56f23fdbb600e6087db7b009775b95ce07cc3195)
Currently how btrfs dio deals with split dio write is not good
enough if dio write is split into several segments due to the
lack of contiguous space, a large dio write like 'dd bs=1G count=1'
can end up with incorrect outstanding_extents counter and endio
would complain loudly with an assertion.
This fixes the problem by compensating the outstanding_extents
counter in inode if a large dio write gets split.
Reported-by: Anand Jain <anand.jain@oracle.com> Tested-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f76ddff6c5215131483efed20acc896e021abb9f)
During relocation of a data block group we create a relocation tree
for each fs/subvol tree by making a snapshot of each tree using
btrfs_copy_root() and the tree's commit root, and then setting the last
snapshot field for the fs/subvol tree's root to the value of the current
transaction id minus 1. However this can lead to relocation later
dropping references that it did not create if we have qgroups enabled,
leaving the filesystem in an inconsistent state that keeps aborting
transactions.
Lets consider the following example to explain the problem, which requires
qgroups to be enabled.
We are relocating data block group Y, we have a subvolume with id 258 that
has a root at level 1, that subvolume is used to store directory entries
for snapshots and we are currently at transaction 3404.
When committing transaction 3404, we have a pending snapshot and therefore
we call btrfs_run_delayed_items() at transaction.c:create_pending_snapshot()
in order to create its dentry at subvolume 258. This results in COWing
leaf A from root 258 in order to add the dentry. Note that leaf A
also contains file extent items referring to extents from some other
block group X (we are currently relocating block group Y). Later on, still
at create_pending_snapshot() we call qgroup_account_snapshot(), which
switches the commit root for root 258 when it calls switch_commit_roots(),
so now the COWed version of leaf A, lets call it leaf A', is accessible
from the commit root of tree 258. At the end of qgroup_account_snapshot(),
we call record_root_in_trans() with 258 as its argument, which results
in btrfs_init_reloc_root() being called, which in turn calls
relocation.c:create_reloc_root() in order to create a relocation tree
associated to root 258, which results in assigning the value of 3403
(which is the current transaction id minus 1 = 3404 - 1) to the
last_snapshot field of root 258. When creating the relocation tree root
at ctree.c:btrfs_copy_root() we add a shared reference for leaf A',
corresponding to the relocation tree's root, when we call btrfs_inc_ref()
against the COWed root (a copy of the commit root from tree 258), which
is at level 1. So at this point leaf A' has 2 references, one normal
reference corresponding to root 258 and one shared reference corresponding
to the root of the relocation tree.
Transaction 3404 finishes its commit and transaction 3405 is started by
relocation when calling merge_reloc_root() for the relocation tree
associated to root 258. In the meanwhile leaf A' is COWed again, in
response to some filesystem operation, when we are still at transaction
3405. However when we COW leaf A', at ctree.c:update_ref_for_cow(), we
call btrfs_block_can_be_shared() in order to figure out if other trees
refer to the leaf and if any such trees exists, add a full back reference
to leaf A' - but btrfs_block_can_be_shared() incorrectly returns false
because the following condition is false:
which evaluates to 3404 <= 3403. So after leaf A' is COWed, it stays with
only one reference, corresponding to the shared reference we created when
we called btrfs_copy_root() to create the relocation tree's root and
btrfs_inc_ref() ends up not being called for leaf A' nor we end up setting
the flag BTRFS_BLOCK_FLAG_FULL_BACKREF in leaf A'. This results in not
adding shared references for the extents from block group X that leaf A'
refers to with its file extent items.
Later, after merging the relocation root we do a call to to
btrfs_drop_snapshot() in order to delete the relocation tree. This ends
up calling do_walk_down() when path->slots[1] points to leaf A', which
results in calling btrfs_lookup_extent_info() to get the number of
references for leaf A', which is 1 at this time (only the shared reference
exists) and this value is stored at wc->refs[0]. After this walk_up_proc()
is called when wc->level is 0 and path->nodes[0] corresponds to leaf A'.
Because the current level is 0 and wc->refs[0] is 1, it does call
btrfs_dec_ref() against leaf A', which results in removing the single
references that the extents from block group X have which are associated
to root 258 - the expectation was to have each of these extents with 2
references - one reference for root 258 and one shared reference related
to the root of the relocation tree, and so we would drop only the shared
reference (because leaf A' was supposed to have the flag
BTRFS_BLOCK_FLAG_FULL_BACKREF set).
This leaves the filesystem in an inconsistent state as we now have file
extent items in a subvolume tree that point to extents from block group X
without references in the extent tree. So later on when we try to decrement
the references for these extents, for example due to a file unlink operation,
truncate operation or overwriting ranges of a file, we fail because the
expected references do not exist in the extent tree.
This leads to warnings and transaction aborts like the following:
This was happening often on openSUSE and SLE systems using btrfs as the
root filesystem (with its default layout where multiple subvolumes are
used) where balance happens in the background triggered by a cron job and
snapshots are automatically created before/after package installations,
upgrades and removals. The issue could be triggered simply by running the
following loop on the first system boot post installation:
while true; do
zypper -n in nfs-kernel-server
zypper -n rm nfs-kernel-server
done
(If we were fast enough and made that loop before the cron job triggered
a balance operation and the balance finished)
So fix by setting the last_snapshot field of the root to the value of the
generation of its commit root. Like this btrfs_block_can_be_shared()
behaves correctly for the case where the relocation root is created during
a transaction commit and for the case where it's created before a
transaction commit.
Fixes: 6426c7ad697d (btrfs: qgroup: Fix qgroup accounting when creating snapshot) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 01f285fe1d885dadfd7439205c700340ec69ab13)
The balance status item contains currently known filter values, but the
stripes filter was unintentionally not among them. This would mean, that
interrupted and automatically restarted balance does not apply the
stripe filters.
Fixes: dee32d0ac3719ef8d640efaf0884111df444730f Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c01ea880e88abedec7c4f02fcd9a110ce73c7ccb)
We can not simply use the owner field from an extent buffer's header to
get the id of the respective tree when the extent buffer is from a
relocation tree. When we create the root for a relocation tree we leave
(on purpose) the owner field with the same value as the subvolume's tree
root (we do this at ctree.c:btrfs_copy_root()). So we must ignore extent
buffers from relocation trees, which have the BTRFS_HEADER_FLAG_RELOC
flag set, because otherwise we will always consider the extent buffer
as not being the root of the tree (the root of original subvolume tree
is always different from the root of the respective relocation tree).
This lead to assertion failures when running with the integrity checker
enabled (CONFIG_BTRFS_FS_CHECK_INTEGRITY=y) such as the following:
This can be easily reproduced by running xfstests with the integrity
checker enabled.
Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit a1e0e0476afb2471f9cee0a995206b053a8241f8)
We were setting the qgroup_rescan_running flag to true only after the
rescan worker started (which is a task run by a queue). So if a user
space task starts a rescan and immediately after asks to wait for the
rescan worker to finish, this second call might happen before the rescan
worker task starts running, in which case the rescan wait ioctl returns
immediatley, not waiting for the rescan worker to finish.
This was making the fstest btrfs/022 fail very often.
Fixes: d2c609b834d6 (btrfs: properly track when rescan worker is running) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1a5ec7dd17a98547618ea7b0ef3bbeb3837a7c49)
In __btrfs_run_delayed_refs, when we put back a delayed ref that's too
new, we have already dropped the lock on locked_ref when we set
->processing = 0.
This patch keeps the lock to cover that assignment.
Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 003e3163fcc76bfdf27c27ef4f5c776bfa925067)
As Jeff explained in c2951f32d36c ("btrfs: remove old tree_root dirent
processing in btrfs_real_readdir()"), supporting this old format is no
longer necessary since the Btrfs magic number has been updated since we
changed to the current format. There are other places where we still
handle this old format, but since this is part of a fix that is going to
stable, I'm only removing this one for now.
Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 79babd4a6ce26d6b0e6a56da47efb723431abc70)
When you snapshot a subvolume containing a subvolume, you get a
placeholder directory where the subvolume would be. These directory
inodes have ->i_ops set to btrfs_dir_ro_inode_operations. Previously,
these i_ops didn't include the xattr operation callbacks. The conversion
to xattr_handlers missed this case, leading to bogus attempts to set
xattrs on these inodes. This manifested itself as failures when running
delayed inodes.
To fix this, clear IOP_XATTR in ->i_opflags on these inodes.
Fixes: 6c6ef9f26e59 ("xattr: Stop calling {get,set,remove}xattr inode operations") Cc: Andreas Gruenbacher <agruenba@redhat.com> Reported-by: Chris Murphy <lists@colorremedies.com> Tested-by: Chris Murphy <lists@colorremedies.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ad80fada9d6d8177d1593a9b5772e80a758db595)
Commit 4c63c2454ef incorrectly assumed that returning -ENOIOCTLCMD would
cause the native ioctl to be called. The ->compat_ioctl callback is
expected to handle all ioctls, not just compat variants. As a result,
when using 32-bit userspace on 64-bit kernels, everything except those
three ioctls would return -ENOTTY.
Fixes: 4c63c2454ef ("btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl") Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 93fb043478b8d81cfa0d2399223bbf96bdb138e8)
Variables start_idx and end_idx are supposed to hold a page index
derived from the file offsets. The int type is not the right one though,
offsets larger than 1 << 44 will get silently trimmed off the high bits.
(1 << 44 is 16TiB)
What can go wrong, if start is below the boundary and end gets trimmed:
- if there's a page after start, we'll find it (radix_tree_gang_lookup_slot)
- the final check "if (page->index <= end_idx)" will unexpectedly fail
The function will return false, ie. "there's no page in the range",
although there is at least one.
btrfs_page_exists_in_range is used to prevent races in:
* in hole punching, where we make sure there are not pages in the
truncated range, otherwise we'll wait for them to finish and redo
truncation, but we're going to replace the pages with holes anyway so
the only problem is the intermediate state
* lock_extent_direct: we want to make sure there are no pages before we
lock and start DIO, to prevent stale data reads
For practical occurence of the bug, there are several constaints. The
file must be quite large, the affected range must cross the 16TiB
boundary and the internal state of the file pages and pending operations
must match. Also, we must not have started any ordered data in the
range, otherwise we don't even reach the buggy function check.
DIO locking tries hard in several places to avoid deadlocks with
buffered IO and avoids waiting for ranges. The worst consequence seems
to be stale data read.
CC: Liu Bo <bo.li.liu@oracle.com> Fixes: fc4adbff823f7 ("btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking") Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 4d15ab90ec2bece7361b6afebebfbf83a381a529)
If we fail to add the space_info kobject, we'll leak the memory
for the percpu counter.
Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs) Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 66d6448475c682099e4dd3c6b4ef6e94248c0b2e)
In NO_HOLES mode, we don't have the [hole] extent any more.
Commit c1aa45759e90 ("Btrfs: fix shrinking truncate when the no_holes feature is enabled")
fixed disk isize not being updated in NO_HOLES mode when data is not flushed.
However, even if data has been flushed, we can still have trouble
in updating disk isize since we updated disk isize to 'start' of
the last evicted extent.
Reviewed-by: Chris Mason <clm@fb.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c3eab85ff11a8cd4def8cf2b4cc0610f6b47a8cd)
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.
Fix the problem by moving posix_acl_update_mode() out of
__btrfs_set_acl() into btrfs_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.
Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: linux-btrfs@vger.kernel.org CC: David Sterba <dsterba@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 157302f97aaa6f79854622a9aab7749fe8661d20)
David Sterba [Mon, 17 Jul 2017 16:11:10 +0000 (18:11 +0200)]
btrfs: prepare for extensions in compression options
This is a minimal patch intended to be backported to older kernels.
We're going to extend the string specifying the compression method and
this would fail on kernels before that change (the string is compared
exactly).
Relax the string matching only to the prefix, ie. ignoring anything that
goes after "zlib" or "lzo", regardless of th format extension we decide
to use. This applies to the mount options and properties.
That way, patched old kernels could be booted on systems already
utilizing the new compression spec.
Josef Bacik [Mon, 24 Jul 2017 19:14:26 +0000 (15:14 -0400)]
btrfs: increase ctx->pos for delayed dir index
Our dir_context->pos is supposed to hold the next position we're
supposed to look. If we successfully insert a delayed dir index we
could end up with a duplicate entry because we don't increase ctx->pos
after doing the dir_emit.
This patch provides a band aid to improve the 'out of the box'
behaviour of btrfs for disks that are detected as being an ssd. In a
general purpose mixed workload scenario, the current ssd mode causes
overallocation of available raw disk space for data, while leaving
behind increasing amounts of unused fragmented free space. This
situation leads to early ENOSPC problems which are harming user
experience and adoption of btrfs as a general purpose filesystem.
This patch modifies the data extent allocation behaviour of the ssd mode
to make it behave identical to nossd mode. The metadata behaviour and
additional ssd_spread option stay untouched so far.
Recommendations for future development are to reconsider the current
oversimplified nossd / ssd distinction and the broken detection
mechanism based on the rotational attribute in sysfs and provide
experienced users with a more flexible way to choose allocator behaviour
for data and metadata, optimized for certain use cases, while keeping
sane 'out of the box' default settings. The internals of the current
btrfs code have more potential than what currently gets exposed to the
user to choose from.
The SSD story...
In the first year of btrfs development, around early 2008, btrfs
gained a mount option which enables specific functionality for
filesystems on solid state devices. The first occurance of this
functionality is in commit e18e4809, labeled "Add mount -o ssd, which
includes optimizations for seek free storage".
The effect on allocating free space for doing (data) writes is to
'cluster' writes together, writing them out in contiguous space, as
opposed to a 'tetris' way of putting all separate writes into any free
space fragment that fits (which is what the -o nossd behaviour does).
A somewhat simplified explanation of what happens is that, when for
example, the 'cluster' size is set to 2MiB, when we do some writes, the
data allocator will search for a free space block that is 2MiB big, and
put the writes in there. The ssd mode itself might allow a 2MiB cluster
to be composed of multiple free space extents with some existing data in
between, while the additional ssd_spread mount option kills off this
option and requires fully free space.
The idea behind this is (commit 536ac8ae): "The [...] clusters make it
more likely a given IO will completely overwrite the ssd block, so it
doesn't have to do an internal rwm cycle."; ssd block meaning nand erase
block. So, effectively this means applying a "locality based algorithm"
and trying to outsmart the actual ssd.
Since then, various changes have been made to the involved code, but the
basic idea is still present, and gets activated whenever the ssd mount
option is active. This also happens by default, when the rotational flag
as seen at /sys/block/<device>/queue/rotational is set to 0.
However, there's a number of problems with this approach.
First, what the optimization is trying to do is outsmart the ssd by
assuming there is a relation between the physical address space of the
block device as seen by btrfs and the actual physical storage of the
ssd, and then adjusting data placement. However, since the introduction
of the Flash Translation Layer (FTL) which is a part of the internal
controller of an ssd, these attempts are futile. The use of good quality
FTL in consumer ssd products might have been limited in 2008, but this
situation has changed drastically soon after that time. Today, even the
flash memory in your automatic cat feeding machine or your grandma's
wheelchair has a full featured one.
Second, the behaviour as described above results in the filesystem being
filled up with badly fragmented free space extents because of relatively
small pieces of space that are freed up by deletes, but not selected
again as part of a 'cluster'. Since the algorithm prefers allocating a
new chunk over going back to tetris mode, the end result is a filesystem
in which all raw space is allocated, but which is composed of
underutilized chunks with a 'shotgun blast' pattern of fragmented free
space. Usually, the next problematic thing that happens is the
filesystem wanting to allocate new space for metadata, which causes the
filesystem to fail in spectacular ways.
Third, the default mount options you get for an ssd ('ssd' mode enabled,
'discard' not enabled), in combination with spreading out writes over
the full address space and ignoring freed up space leads to worst case
behaviour in providing information to the ssd itself, since it will
never learn that all the free space left behind is actually free. There
are two ways to let an ssd know previously written data does not have to
be preserved, which are sending explicit signals using discard or
fstrim, or by simply overwriting the space with new data. The worst
case behaviour is the btrfs ssd_spread mount option in combination with
not having discard enabled. It has a side effect of minimizing the reuse
of free space previously written in.
Fourth, the rotational flag in /sys/ does not reliably indicate if the
device is a locally attached ssd. For example, iSCSI or NBD displays as
non-rotational, while a loop device on an ssd shows up as rotational.
The combination of the second and third problem effectively means that
despite all the good intentions, the btrfs ssd mode reliably causes the
ssd hardware and the filesystem structures and performance to be choked
to death. The clickbait version of the title of this story would have
been "Btrfs ssd optimizations considered harmful for ssds".
The current nossd 'tetris' mode (even still without discard) allows a
pattern of overwriting much more previously used space, causing many
more implicit discards to happen because of the overwrite information
the ssd gets. The actual location in the physical address space, as seen
from the point of view of btrfs is irrelevant, because the actual writes
to the low level flash are reordered anyway thanks to the FTL.
Changes made in the code
1. Make ssd mode data allocation identical to tetris mode, like nossd.
2. Adjust and clean up filesystem mount messages so that we can easily
identify if a kernel has this patch applied or not, when providing
support to end users. Also, make better use of the *_and_info helpers to
only trigger messages on actual state changes.
Backporting notes
Notes for whoever wants to backport this patch to their 4.9 LTS kernel:
* First apply commit 951e7966 "btrfs: drop the nossd flag when
remounting with -o ssd", or fixup the differences manually.
* The rest of the conflicts are because of the fs_info refactoring. So,
for example, instead of using fs_info, it's root->fs_info in
extent-tree.c
Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 608e94b83609e69bc361eb5fabe8ac1745435918)
Chun-Hao Lin [Fri, 29 Jul 2016 08:37:56 +0000 (16:37 +0800)]
r8169: fix nic may not work after changing mac address.
When there is no AC power, NIC may not work after changing mac address.
Please refer to following link.
http://www.spinics.net/lists/netdev/msg356572.html
This issue is caused by runtime power management. When there is no AC
power, if we put NIC down (ifconfig down), the driver will be in runtime
suspend state and hardware will be put into D3 state. During this time,
driver cannot access hardware regisers. So if you set new mac address
during this time, it will not be set to hardware. After resume, NIC will
keep using the old mac address and the network will not work normally.
In this patch I add detecting runtime pm status when setting mac address.
If driver is in runtime suspend state, it will skip setting mac address, keep
the new mac address, and set the new mac address during runtime resume.
Signed-off-by: Chunhao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit f51d4a10ac39ecf06b25e7a79121b06f7ed59928)
Edmund Nadolski [Thu, 29 Jun 2017 03:57:03 +0000 (21:57 -0600)]
btrfs: add cond_resched() calls when resolving backrefs
Since backref resolution is CPU-intensive, the cond_resched calls
should help alleviate soft lockup occurences.
Signed-off-by: Edmund Nadolski <enadolski@suse.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 053582a7d4231dad74484be1c975200e9831fac0)
Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of
mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the
end of unmapped_area_topdown(). Linus points out how MAP_FIXED
(which does not have to respect our stack guard gap intentions)
could result in gap_end below gap_start there. Fix that, and
the similar case in its alternative, unmapped_area().
Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas") Reported-by: Dave Jones <davej@codemonkey.org.uk> Debugged-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1f2284fac2180d7a9442c796d9755e3ce7ab0bd9)
Fix expand_upwards() on architectures with an upward-growing stack (parisc,
metag and partly IA-64) to allow the stack to reliably grow exactly up to
the address space limit given by TASK_SIZE.
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.
This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.
Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.
One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).
Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.
Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes] Signed-off-by: Willy Tarreau <w@1wt.eu>
[gkh: minor build fixes for 4.4] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 4b359430674caa2c98d0049a6941f157d2a33741)
Btrfs: compression must free at least one sector size
We already skip storing data where compression does not make the result
at least one byte less. Let's make the logic better and check
that compression frees at least one sector size of bytes, otherwise it's
not that useful.
Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com>
[ changelog updated ] Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 170607ebd9c891d6765445434460065b2e73ca51)
Colin Ian King [Tue, 9 May 2017 17:14:01 +0000 (18:14 +0100)]
btrfs: fix incorrect error return ret being passed to mapping_set_error
The setting of return code ret should be based on the error code
passed into function end_extent_writepage and not on ret. Thanks
to Liu Bo for spotting this mistake in the original fix I submitted.
Detected by CoverityScan, CID#1414312 ("Logically dead code")
Fixes: 5dca6eea91653e ("Btrfs: mark mapping with error flag to report errors to userspace") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 47af8d7adf66d5e50d05e7698e1e31c2e26836c6)
Filipe Manana [Tue, 14 Feb 2017 16:56:01 +0000 (16:56 +0000)]
Btrfs: fix data loss after truncate when using the no-holes feature
If we have a file with an implicit hole (NO_HOLES feature enabled) that
has an extent following the hole, delayed writes against regions of the
file behind the hole happened before but were not yet flushed and then
we truncate the file to a smaller size that lies inside the hole, we
end up persisting a wrong disk_i_size value for our inode that leads to
data loss after umounting and mounting again the filesystem or after
the inode is evicted and loaded again.
This happens because at inode.c:btrfs_truncate_inode_items() we end up
setting last_size to the offset of the extent that we deleted and that
followed the hole. We then pass that value to btrfs_ordered_update_i_size()
which updates the inode's disk_i_size to a value smaller then the offset
of the buffered (delayed) writes.
Cc: <stable@vger.kernel.org> # 3.14+ Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
(cherry picked from commit 76b42abbf7488121c4f9f1ea5941123306e25d99)
Filipe Manana [Tue, 21 Feb 2017 17:14:52 +0000 (17:14 +0000)]
Btrfs: fix deadlock between dedup on same file and starting writeback
If we are deduping two ranges of the same file we need to make sure that
we lock all pages in ascending order, that is, lock first the pages from
the range with lower offset and then the pages from the other range, as
otherwise we can deadlock with a concurrent task that is starting delalloc
(writeback). Example trace:
btrfs_dedupe_file_range()
--> using same inode as source
and target
--> src range is [768K, 1Mb[
--> dst range is [0, 256K[
btrfs_cmp_data_prepare()
--> calls gather_extent_pages()
for range [768K, 1Mb[ and
locks all pages in that range
do_writepages()
btrfs_writepages()
extent_writepages()
extent_write_cache_pages()
__extent_writepage()
writepage_delalloc()
find_lock_delalloc_range()
--> finds range [0, 1Mb[
lock_delalloc_pages()
--> locks all pages in the
range [0, 768K[
--> tries to lock page at
offset 768K
--> deadlock
--> calls gather_extent_pages()
to lock pages in the range
[0, 256K[
--> deadlock, task at CPU 1
already locked that
range and it's trying
to lock the range we
locked previously
So fix this by making sure that during a dedup we always lock first the
pages from the range with lower offset.
commit 909c3a22da3 (Btrfs: fix loading of orphan roots leading to BUG_ON)
avoids the BUG_ON but can add an aliased root to the dead_roots list or
leak the root.
Since we've already been loading roots into the radix tree, we should
use it before looking the root up on disk.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ff3235105fc7e4ecf04eb308940821d4a098c08d)
Matthew Wilcox [Wed, 14 Dec 2016 23:08:46 +0000 (15:08 -0800)]
btrfs: fix race in btrfs_free_dummy_fs_info()
We drop the lock which protects the radix tree, so we must call
radix_tree_iter_next() in order to avoid a modification to the tree
invalidating the iterator state.
Link: http://lkml.kernel.org/r/1480369871-5271-54-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit b35df27a39f40e39fabf1b1e9569c7b24e1add6a)
Liu Bo [Thu, 1 Dec 2016 00:20:25 +0000 (16:20 -0800)]
Btrfs: fix lockdep warning about log_mutex
While checking INODE_REF/INODE_EXTREF for a corner case, we may acquire a
different inode's log_mutex with holding the current inode's log_mutex, and
lockdep has complained this with a possilble deadlock warning.
Fix this by using mutex_lock_nested() when processing the other inode's
log_mutex.
Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
(cherry picked from commit 958dcc5403af9bbe9647d6c038f335cf429dbe46)
Omar Sandoval [Wed, 9 Nov 2016 23:26:50 +0000 (15:26 -0800)]
Btrfs: deal with existing encompassing extent map in btrfs_get_extent()
My QEMU VM was seeing inexplicable I/O errors that I tracked down to
errors coming from the qcow2 virtual drive in the host system. The qcow2
file is a nocow file on my Btrfs drive, which QEMU opens with O_DIRECT.
Every once in awhile, pread() or pwrite() would return EEXIST, which
makes no sense. This turned out to be a bug in btrfs_get_extent().
Commit 8dff9c853410 ("Btrfs: deal with duplciates during extent_map
insertion in btrfs_get_extent") fixed a case in btrfs_get_extent() where
two threads race on adding the same extent map to an inode's extent map
tree. However, if the added em is merged with an adjacent em in the
extent tree, then we'll end up with an existing extent that is not
identical to but instead encompasses the extent we tried to add. When we
call merge_extent_mapping() to find the nonoverlapping part of the new
em, the arithmetic overflows because there is no such thing. We then end
up trying to add a bogus em to the em_tree, which results in a EEXIST
that can bubble all the way up to userspace.
Fix it by extending the identical extent map special case.
Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 8e2bd3b7fac91b79a6115fd1511ca20b2a09696d)
Robbie Ko [Fri, 28 Oct 2016 02:32:54 +0000 (10:32 +0800)]
Btrfs: fix enospc in hole punching
The hole punching can result in adding new leafs (and as a consequence
new nodes) to the tree because when we find file extent items that span
beyond the hole range we may end up not deleting them (just adjusting
them, reducing their range by reducing their length or increasing their
offset field) and add new file extent items representing holes.
So after splitting a leaf (therefore creating a new one) to insert a new
file extent item representing a hole, a new node might be added to each
level of the tree in the worst case scenario (since there's a new key
and every parent node was full).
For example if a file has an extent item representing the range 0 to 64Mb
and we punch a hole in the range 1Mb to 20Mb, the existing extent item is
duplicated and one of the copies is adjusted to represent the range 0 to
1Mb, the other copy adjusted to represent the range 20Mb to 64Mb, and a
new file extent item representing a hole in the range 1Mb to 20Mb is
inserted.
Fix this by using btrfs_calc_trans_metadata_size() instead of
btrfs_calc_trunc_metadata_size(), so that enough metadata space is
reserved for the worst possible case.
Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Modified changelog for clarity and correctness]
Robbie Ko [Fri, 7 Oct 2016 09:30:47 +0000 (17:30 +0800)]
Btrfs: fix tree search logic when replaying directory entry deletes
If a log tree has a layout like the following:
leaf N:
...
item 240 key (282 DIR_LOG_ITEM 0) itemoff 8189 itemsize 8
dir log end 1275809046
leaf N + 1:
item 0 key (282 DIR_LOG_ITEM 3936149215) itemoff 16275 itemsize 8
dir log end 18446744073709551615
...
When we pass the value 1275809046 + 1 as the parameter start_ret to the
function tree-log.c:find_dir_range() (done by replay_dir_deletes()), we
end up with path->slots[0] having the value 239 (points to the last item
of leaf N, item 240). Because the dir log item in that position has an
offset value smaller than *start_ret (1275809046 + 1) we need to move on
to the next leaf, however the logic for that is wrong since it compares
the current slot to the number of items in the leaf, which is smaller
and therefore we don't lookup for the next leaf but instead we set the
slot to point to an item that does not exist, at slot 240, and we later
operate on that slot which has unexpected content or in the worst case
can result in an invalid memory access (accessing beyond the last page
of leaf N's extent buffer).
So fix the logic that checks when we need to lookup at the next leaf
by first incrementing the slot and only after to check if that slot
is beyond the last item of the current leaf.
Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: e02119d5a7b4 (Btrfs: Add a write ahead tree log to optimize synchronous operations) Cc: stable@vger.kernel.org # 2.6.29+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Modified changelog for clarity and correctness]
Robbie Ko [Fri, 28 Oct 2016 02:48:26 +0000 (10:48 +0800)]
Btrfs: fix deadlock caused by fsync when logging directory entries
While logging new directory entries, at tree-log.c:log_new_dir_dentries(),
after we call btrfs_search_forward() we get a leaf with a read lock on it,
and without unlocking that leaf we can end up calling btrfs_iget() to get
an inode pointer. The later (btrfs_iget()) can end up doing a read-only
search on the same tree again, if the inode is not in memory already, which
ends up causing a deadlock if some other task in the meanwhile started a
write search on the tree and is attempting to write lock the same leaf
that btrfs_search_forward() locked while holding write locks on upper
levels of the tree blocking the read search from btrfs_iget(). In this
scenario we get a deadlock.
So fix this by releasing the search path before calling btrfs_iget() at
tree-log.c:log_new_dir_dentries().
While free'ing qgroup->reserved resources, we much check if
the page has not been invalidated by a truncate operation
by checking if the page is still dirty before reducing the
qgroup resources. Resources in such a case are free'd when
the entire extent is released by delayed_ref.
This fixes a double accounting while releasing resources
in case of truncating a file, reproduced by the following testcase.
SCRATCH_DEV=/dev/vdb
SCRATCH_MNT=/mnt
mkfs.btrfs -f $SCRATCH_DEV
mount -t btrfs $SCRATCH_DEV $SCRATCH_MNT
cd $SCRATCH_MNT
btrfs quota enable $SCRATCH_MNT
btrfs subvolume create a
btrfs qgroup limit 500m a $SCRATCH_MNT
sync
for c in {1..15}; do
dd if=/dev/zero bs=1M count=40 of=$SCRATCH_MNT/a/file;
done
sleep 10
sync
sleep 5
touch $SCRATCH_MNT/a/newfile
echo "Removing file"
rm $SCRATCH_MNT/a/file
Fixes: b9d0b38928 ("btrfs: Add handler for invalidate page") Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 591bf1362e9ec873110332e6914428a8aff84072)
When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.
References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ea288a690cc4e53a528ae6a1d37cd6e14320ed27)
In convert_free_space_to_{bitmaps,extents}(), we buffer the free space
bitmaps in memory and copy them directly to/from the extent buffers with
{read,write}_extent_buffer(). The extent buffer bitmap helpers use byte
granularity, which is equivalent to a little-endian bitmap. This means
that on big-endian systems, the in-memory bitmaps will be written to
disk byte-swapped. To fix this, use byte-granularity for the bitmaps in
memory.
Fixes: a5ed91828518 ("Btrfs: implement the free space B-tree") Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 1ff6341b5d92dd6b68b12508c143e174ec2caabe)
Wang Xiaoguang [Wed, 26 Oct 2016 10:07:33 +0000 (18:07 +0800)]
btrfs: improve delayed refs iterations
This issue was found when I tried to delete a heavily reflinked file,
when deleting such files, other transaction operation will not have a
chance to make progress, for example, start_transaction() will blocked
in wait_current_trans(root) for long time, sometimes it even triggers
soft lockups, and the time taken to delete such heavily reflinked file
is also very large, often hundreds of seconds. Using perf top, it reports
that:
PerfTop: 7416 irqs/sec kernel:99.8% exact: 0.0% [4000Hz cpu-clock], (all, 4 CPUs)
---------------------------------------------------------------------------------------
84.37% [btrfs] [k] __btrfs_run_delayed_refs.constprop.80
11.02% [kernel] [k] delay_tsc
0.79% [kernel] [k] _raw_spin_unlock_irq
0.78% [kernel] [k] _raw_spin_unlock_irqrestore
0.45% [kernel] [k] do_raw_spin_lock
0.18% [kernel] [k] __slab_alloc
It seems __btrfs_run_delayed_refs() took most cpu time, after some debug
work, I found it's select_delayed_ref() causing this issue, for a delayed
head, in our case, it'll be full of BTRFS_DROP_DELAYED_REF nodes, but
select_delayed_ref() will firstly try to iterate node list to find
BTRFS_ADD_DELAYED_REF nodes, obviously it's a disaster in this case, and
waste much time.
To fix this issue, we introduce a new ref_add_list in struct btrfs_delayed_ref_head,
then in select_delayed_ref(), if this list is not empty, we can directly use
nodes in this list. With this patch, it just took about 10~15 seconds to
delte the same file. Now using perf top, it reports that:
For normal files, this patch also gives help, at least we do not need to
iterate whole list to found BTRFS_ADD_DELAYED_REF nodes.
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit a7f8e4065495905d8322958d574c5077c88c2bfc)
Nick Terrell [Wed, 2 Nov 2016 03:25:27 +0000 (20:25 -0700)]
btrfs: Call kunmap if zlib_inflateInit2 fails
If zlib_inflateInit2 fails, the input page is never unmapped.
Add a call to kunmap when it fails.
Signed-off-by: Nick Terrell <nickrterrell@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 9cd09e509cfe3cb78a330b47d53a27e1ed7ceab4)
Josef Bacik [Wed, 16 Nov 2016 14:13:39 +0000 (09:13 -0500)]
Btrfs: fix file extent corruption
In order to do hole punching we have a block reserve to hold the reservation we
need to drop the extents in our range. Since we could end up dropping a lot of
extents we set rsv->failfast so we can just loop around again and drop the
remaining of the range. Unfortunately we unconditionally fill the hole extents
in and start from the last extent we encountered, which we may or may not have
dropped. So this can result in overlapping file extent entries, which can be
tripped over in a variety of ways, either by hitting BUG_ON(!ret) in
fill_holes() after the search, or in btrfs_set_item_key_safe() in
btrfs_drop_extent() at a later time by an unrelated task. Fix this by only
setting drop_end to the last extent we did actually drop. This way our holes
are filled in properly for the range that we did drop, and the rest of the range
that remains to be dropped is actually dropped. Thanks,
Liu Bo [Fri, 2 Sep 2016 19:35:34 +0000 (12:35 -0700)]
Btrfs: fix BUG_ON in btrfs_mark_buffer_dirty
This can only happen with CONFIG_BTRFS_FS_CHECK_INTEGRITY=y.
Commit 1ba98d0 ("Btrfs: detect corruption when non-root leaf has zero item")
assumes that a leaf is its root when leaf->bytenr == btrfs_root_bytenr(root),
however, we should not use btrfs_root_bytenr(root) since it's mainly got
updated during committing transaction. So the check can fail when doing
COW on this leaf while it is a root.
This changes to use "if (leaf == btrfs_root_node(root))" instead, just like
how we check whether leaf is a root in __btrfs_cow_block().
Fixes: 1ba98d086fe3 (Btrfs: detect corruption when non-root leaf has zero item) Cc: stable@vger.kernel.org # 4.8+ Reported-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Filipe Manana <fdmanana@suse.com>
(cherry picked from commit ef85b25e982b5bba1530b936e283ef129f02ab9d)
Liu Bo [Fri, 11 Nov 2016 22:27:45 +0000 (14:27 -0800)]
Btrfs: fix truncate down when no_holes feature is enabled
For such a file mapping,
[0-4k][hole][8k-12k]
In NO_HOLES mode, we don't have the [hole] extent any more.
Commit c1aa45759e90 ("Btrfs: fix shrinking truncate when the no_holes feature is enabled")
fixed disk isize not being updated in NO_HOLES mode when data is not flushed.
However, even if data has been flushed, we can still have trouble
in updating disk isize since we updated disk isize to 'start' of
the last evicted extent.
Also add a ASSERT for better catching (for developers only).
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 1b2a1228d0e63512fb3d32b41d4398bf32ac3594)
Wang Xiaoguang [Fri, 21 Oct 2016 09:05:07 +0000 (17:05 +0800)]
btrfs: imporve delayed refs iterations
This issue was found when I tried to delete a heavily reflinked file,
when deleting such files, other transaction operation will not have a
chance to make progress, for example, start_transaction() will blocked
in wait_current_trans(root) for long time, sometimes it even triggers
soft lockups, and the time taken to delete such heavily reflinked file
is also very large, often hundreds of seconds. Using perf top, it reports
that:
PerfTop: 7416 irqs/sec kernel:99.8% exact: 0.0% [4000Hz cpu-clock], (all, 4 CPUs)
---------------------------------------------------------------------------------------
84.37% [btrfs] [k] __btrfs_run_delayed_refs.constprop.80
11.02% [kernel] [k] delay_tsc
0.79% [kernel] [k] _raw_spin_unlock_irq
0.78% [kernel] [k] _raw_spin_unlock_irqrestore
0.45% [kernel] [k] do_raw_spin_lock
0.18% [kernel] [k] __slab_alloc
It seems __btrfs_run_delayed_refs() took most cpu time, after some debug
work, I found it's select_delayed_ref() causing this issue, for a delayed
head, in our case, it'll be full of BTRFS_DROP_DELAYED_REF nodes, but
select_delayed_ref() will firstly try to iterate node list to find
BTRFS_ADD_DELAYED_REF nodes, obviously it's a disaster in this case, and
waste much time.
To fix this issue, we introduce a new ref_add_list in struct btrfs_delayed_ref_head,
then in select_delayed_ref(), if this list is not empty, we can directly use
nodes in this list. With this patch, it just took about 10~15 seconds to
delte the same file. Now using perf top, it reports that:
The last truncate operation will fail for ENOSPC reason, but indeed
it should not fail.
In btrfs_truncate(), we use a temporary block_rsv to do truncate
operation. With every btrfs_truncate_inode_items() call, we migrate space
to this block_rsv, but forget to cleanup previous reservation, which
will make this block_rsv's reserved bytes keep growing, and this reserved
space will only be released in the end of btrfs_truncate(), this metadata
leak will impact other's metadata reservation. In this case, it's
"btrfs_start_transaction(root, 2);" fails for enospc error, which make
this truncate operation fail.
Wang Xiaoguang [Fri, 9 Sep 2016 08:17:48 +0000 (16:17 +0800)]
btrfs: should block unused block groups deletion work when allocating data space
cleaner_kthread() may run at any time, in which it'll call btrfs_delete_unused_bgs()
to delete unused block groups. Because this work is asynchronous, it may also result
in false ENOSPC error. Please see below race window:
CPU1 | CPU2
|
|-> btrfs_alloc_data_chunk_ondemand() |-> cleaner_kthread()
|-> do_chunk_alloc() | |
| assume it returns ENOSPC, which means | |
| btrfs_space_info is full and have free| |
| space to satisfy data request. | |
| | |- > btrfs_delete_unused_bgs()
| | | it will decrease btrfs_space_info
| | | total_bytes and make
| | | btrfs_space_info is not full.
| | |
In this case, we may get ENOSPC error, but btrfs_space_info is not full.
To fix this issue, in btrfs_alloc_data_chunk_ondemand(), if we need to call
do_chunk_alloc() to allocating new chunk, we should block btrfs_delete_unused_bgs().
Here we introduce a new struct rw_semaphore bg_delete_sem to do this job.
Indeed there is already a "struct mutex delete_unused_bgs_mutex", but it's mutex,
we can not use it for this purpose. Of course, we can re-define it to be struct
rw_semaphore, then use it in btrfs_alloc_data_chunk_ondemand(). Either method will
work.
But given that delete_unused_bgs_mutex's name length is longer than bg_delete_sem,
I choose the first method, to create a new struct rw_semaphore bg_delete_sem and
delete delete_unused_bgs_mutex :)
Chris Mason [Thu, 27 Oct 2016 17:42:20 +0000 (10:42 -0700)]
btrfs: fix races on root_log_ctx lists
btrfs_remove_all_log_ctxs takes a shortcut where it avoids walking the
list because it knows all of the waiters are patiently waiting for the
commit to finish.
But, there's a small race where btrfs_sync_log can remove itself from
the list if it finds a log commit is already done. Also, it uses
list_del_init() to remove itself from the list, but there's no way to
know if btrfs_remove_all_log_ctxs has already run, so we don't know for
sure if it is safe to call list_del_init().
This gets rid of all the shortcuts for btrfs_remove_all_log_ctxs(), and
just calls it with the proper locking.
This is part two of the corruption fixed by cbd60aa7cd1. I should have
done this in the first place, but convinced myself the optimizations were
safe. A 12 hour run of dbench 2048 will eventually trigger a list debug
WARN_ON for the list_del_init() in btrfs_sync_log().
Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4 Reported-by: Dave Jones <davej@codemonkey.org.uk>
cc: stable@vger.kernel.org # 3.15+ Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 570dd45042a7c8a7aba1ee029c5dd0f5ccf41b9b)
Filipe Manana [Fri, 28 Oct 2016 09:15:02 +0000 (10:15 +0100)]
Btrfs: remove balance warning that does not reflect any problem
On openSUSE/SLE systems where balance is triggered periodically in the
background, snapshotting happens when doing package installations and
upgrades, and (by default) the root system is organized with multiple
subvolumes, the following warning was triggered often:
It turned out that this warning does not reflect any problem and just
makes users/system administrators worry about something going wrong.
The warning happens because when we create a relocation root (which is
just a snapshot of a subvolume tree) we set its last_snapshot field (as
well as for the subvolume's tree root) to a value corresponding to the
generation of the current transaction minus 1 (we do this at
relocation.c:create_reloc_root()). This means that when we merge the
relocation tree with the corresponding subvolume tree, at
walk_down_reloc_tree() we can catch pointers (bytenr/generation pairs)
with a generation that matches the generation of the transaction where
we created the relocation root, so those pointers correspond to tree
blocks created either before or after the relocation root was created.
If they were created before the relocation root (and in the same
transaction) we hit the warning, which we can safely remove because it
means the tree blocks are accessible from both trees (the subvolume
tree and the relocation tree).
So fix this by removing the warning and adding a couple assertions that
verify the pointer generations match and that their generation matches
the value of the last_snapshot field from the relocation tree plus 1.
When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.
References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ea288a690cc4e53a528ae6a1d37cd6e14320ed27)
Wang Xiaoguang [Thu, 13 Oct 2016 01:23:39 +0000 (09:23 +0800)]
btrfs: make file clone aware of fatal signals
Indeed this just make the behavior similar to xfs when process has
fatal signals pending, and it'll make fstests/generic/298 happy.
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 78147c6ba4c3f46ce78501852487af6392bddb00)
This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").
In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better). The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9. Earlier kernels will
have to look at the page state itself.
Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.
To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.
btrfs: fix silent data corruption while reading compressed inline extents
rsync -S causes a large number of small writes separated by small seeks
to form sparse holes in files that contain runs of zero bytes. Rarely,
this can lead btrfs to write a file with a compressed inline extent
followed by other data, like this:
Filesystem type is: 9123683e
File size of /try/./30/share/locale/nl/LC_MESSAGES/tar.mo is 61906 (16 blocks of 4096 bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 4095: 0.. 4095: 4096: encoded,not_aligned,inline
1: 1.. 15: 331372.. 331386: 15: 1: last,encoded,eof
/try/./30/share/locale/nl/LC_MESSAGES/tar.mo: 2 extents found
The inline extent size is less than the page size, so the ram_bytes field
in the extent is smaller than 4096. The difference between ram_bytes and
the end of the first page of the file forms a small hole. Like any other
hole, he correct value of each byte within the hole is zero.
When the inline extent is not compressed, btrfs_get_extent copies the
inline extent data and then memsets the remainder of the page to zero.
There is no corruption in this case.
When the inline extent is compressed, uncompress_inline uses the
ram_bytes field from the extent ref as the size of the uncompressed data.
ram_bytes is smaller than the page size, so the remainder of the page
(i.e. the bytes in the small hole) is uninitialized memory. Each time the
extent is read into the page cache, userspace may see different contents.
Fix this by zeroing out the difference between the size of the
uncompressed inline extent and PAGE_CACHE_SIZE in uncompress_inline.
Only bytes within the hole are affected, so affected files can be read
correctly with a fixed kernel. The corruption happens after IO and
checksum validation, so the corruption is never reported in dmesg or
counted in dev stats.
The bug is at least as old as 3.5.7 (the oldest kernel I can conveniently
test), and possibly much older.
The code may not be correct if the extent is larger than a page, so add
a WARN_ON for that case.
To reproduce the bug, run this on a 3072M kvm VM:
#!/bin/sh
# Use your favorite block device here
blk=/dev/vdc
# Create test filesystem and mount point
mkdir -p /try
mkfs.btrfs -dsingle -mdup -O ^extref,^skinny-metadata,^no-holes -f "$blk" || exit 1
mount -ocompress-force,flushoncommit,max_inline=8192,noatime "$blk" /try || exit 1
# Create a few inline extents in larger files.
# Multiple processes seem to be necessary.
y=/usr; for x in $(seq 10 19); do rsync -axHSWI "$y/." "$x"; y="$x"; done &
y=/usr; for x in $(seq 20 29); do rsync -axHSWI "$y/." "$x"; y="$x"; done &
y=/usr; for x in $(seq 30 39); do rsync -axHSWI "$y/." "$x"; y="$x"; done &
y=/usr; for x in $(seq 40 49); do rsync -axHSWI "$y/." "$x"; y="$x"; done &
wait
# Make a list of the files with inline extents
touch /try/list
find -type f -size +4097c -exec sh -c 'for x; do if filefrag -v "$x" | sed -n "4p" | grep -q "inline"; then echo "$x" >> list; fi; done' -- {} +
# Check the inline extents to see if they change as they are read multiple times
while read -r x; do
sum="$(sha1sum "$x")"
for y in $(seq 0 99); do
sysctl vm.drop_caches=1
sum2="$(sha1sum "$x")"
if [ "$sum" != "$sum2" ]; then
echo "Inconsistent reads from '$x'"
exit 1
fi
done
done < list
The reproducer may need to run up to 20 times before it finds a
corruption.
Wang Xiaoguang [Tue, 11 Oct 2016 06:47:42 +0000 (14:47 +0800)]
btrfs: make max inline data can be equal to sectorsize
If we use mount option "-o max_inline=sectorsize", say 4096, indeed
even for a fresh fs, say nodesize is 16k, we can not make the first
4k data completely inline, I found this conditon causing this issue:
!compressed_size && (actual_end & (root->sectorsize - 1)) == 0
If it retuns true, we'll not make data inline. For 4k sectorsize,
0~4094 dara range, we can make it inline, but 0~4095, it can not.
I don't think this limition is useful, so here remove it which will
make max inline data can be equal to sectorsize.
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Zygo Blaxell [Tue, 11 Oct 2016 22:34:58 +0000 (18:34 -0400)]
Revert "btrfs: use correct size for memset", "btrfs: do not rely on
decompress to zero end of buffer", and "btrfs: fix data corruption while
reading compressed inline extents followed by other extents"
Filipe Manana [Tue, 23 Aug 2016 20:13:51 +0000 (21:13 +0100)]
Btrfs: fix lockdep warning on deadlock against an inode's log mutex
Commit 44f714dae50a ("Btrfs: improve performance on fsync against new
inode after rename/unlink"), which landed in 4.8-rc2, introduced a
possibility for a deadlock due to double locking of an inode's log mutex
by the same task, which lockdep reports with:
[23045.433975] =============================================
[23045.434748] [ INFO: possible recursive locking detected ]
[23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted
[23045.436044] ---------------------------------------------
[23045.436044] xfs_io/3688 is trying to acquire lock:
[23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044]
but task is already holding lock:
[23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs]
[23045.436044]
other info that might help us debug this:
[23045.436044] Possible unsafe locking scenario:
This is because while logging the inode of file bar we end up logging its
parent directory (since its inode has an unlink_trans field matching the
current transaction id due to the rename operation), which in turn logs
the inodes for all its new dentries, so that the new inode for the new
file named foo gets logged which in turn triggered another logging attempt
for the inode we are fsync'ing, since that inode had an old name that
corresponds to the name of the new inode.
So fix this by ensuring that when logging the inode for a new dentry that
has a name matching an old name of some other inode, we don't log again
the original inode that we are fsync'ing.
Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 28a235931b56d4e7bdd51f6733daf95f2b269da8)
If the subvol/snapshot create/destroy ioctls are passed a regular file
with execute permissions set, we'll eventually Oops while trying to do
inode->i_op->lookup via lookup_one_len.
This patch ensures that the file descriptor refers to a directory.
btrfs: fix data corruption while reading compressed inline extents followed by other extents
rsync -S causes a large number of small writes separated by small seeks
to form sparse holes in files that contain runs of zero bytes. This can
lead btrfs to write a file with an inline extent followed by other data,
like this:
Filesystem type is: 9123683e
File size of share/locale/bs/LC_MESSAGES/glib20.mo is 12368 (4 blocks of 4096 bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 4095: 0.. 4095: 4096: not_aligned,inline
1: 1.. 3: 1884391.. 1884393: 3: 1: last,encoded,eof
share/locale/bs/LC_MESSAGES/glib20.mo: 2 extents found
Typically the inline extent size is less than the page size.
When the inline extent is not compressed, btrfs_get_extent copies the
inline extent data and then memsets the remainder of the page to zero.
When the inline extent is compressed, uncompress_inline passes the
ram_bytes field from the extent to btrfs_decompress as the size of the
buffer. Unfortunately, ram_bytes is less than PAGE_CACHE_SIZE, and in
cases where there are other extents following the initial inline extent,
the difference between the two sizes is filled with uninitialized data
that ends up in userspace.
Fix this by passing PAGE_CACHE_SIZE to btrfs_decompress as the buffer
size.
Liu Bo [Wed, 14 Sep 2016 15:51:46 +0000 (08:51 -0700)]
Btrfs: return gracefully from balance if fs tree is corrupted
When relocating tree blocks, we firstly get block information from
back references in the extent tree, we then search fs tree to try to
find all parents of a block.
However, if fs tree is corrupted, eg. if there're some missing
items, we could come across these WARN_ONs and BUG_ONs.
This makes us print some error messages and return gracefully
from balance.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit ecc3b8e78e181e4769012e2a6ce3294307fdf766)
Liu Bo [Wed, 14 Sep 2016 02:15:48 +0000 (19:15 -0700)]
Btrfs: remove BUG_ON in start_transaction
Since we could get errors from the concurrent aborted transaction,
the check of this BUG_ON in start_transaction is not true any more.
Say, while flushing free space cache inode's dirty pages,
btrfs_finish_ordered_io
-> btrfs_join_transaction_nolock
(the transaction has been aborted.)
-> BUG_ON(type == TRANS_JOIN_NOLOCK);
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 78c2a8dcd723840f0ef6e3b429e846b25e33391d)
Liu Bo [Thu, 15 Sep 2016 00:23:39 +0000 (17:23 -0700)]
Btrfs: add error handling for extent buffer in print tree
Somehow we missed btrfs_print_tree when last time we
updated error handling for read_extent_block().
This keeps us from getting a NULL pointer panic when
btrfs_print_tree's read_extent_block() fails.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit adb6732941f1171c452f2cd3cc89ee53df361a44)
Josef Bacik [Tue, 23 Aug 2016 17:17:58 +0000 (13:17 -0400)]
Btrfs: kill invalid ASSERT() in process_all_refs()
Suppose you have the following tree in snap1 on a file system mounted with -o
inode_cache so that inode numbers are recycled
└── [ 258] a
└── [ 257] b
and then you remove b, rename a to c, and then re-create b in c so you have the
following tree
└── [ 258] c
└── [ 257] b
and then you try to do an incremental send you will hit
ASSERT(pending_move == 0);
in process_all_refs(). This is because we assume that any recycling of inodes
will not have a pending change in our path, which isn't the case. This is the
case for the DELETE side, since we want to remove the old file using the old
path, but on the create side we could have a pending move and need to do the
normal pending rename dance. So remove this ASSERT() and put a comment about
why we ignore pending_move. Thanks,
Josef Bacik [Fri, 2 Sep 2016 19:25:43 +0000 (15:25 -0400)]
Btrfs: don't leak reloc root nodes on error
We don't track the reloc roots in any sort of normal way, so the only way the
root/commit_root nodes get free'd is if the relocation finishes successfully and
the reloc root is deleted. Fix this by free'ing them in free_reloc_roots.
Thanks,
Liu Bo [Thu, 15 Sep 2016 02:19:05 +0000 (19:19 -0700)]
Btrfs: kill BUG_ON in run_delayed_tree_ref
In a corrupted btrfs image, we can come across this BUG_ON and
get an unreponsive system, but if we return errors instead,
its caller can handle everything gracefully by aborting the current
transaction.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 0c4aa1adb137011af66259ed5fa20e95ad500baf)
Josef Bacik [Thu, 22 Sep 2016 15:04:56 +0000 (17:04 +0200)]
Btrfs: don't BUG() during drop snapshot
Really there's lots of things that can go wrong here, kill all the
BUG_ON()'s and replace the logic ones with ASSERT()'s and return EIO
instead.
Signed-off-by: Josef Bacik <jbacik@fb.com>
[ switched to btrfs_err ] Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit c52381e9337a498d7e45fffe062606977fc34764)
Liu Bo [Wed, 14 Sep 2016 02:02:27 +0000 (19:02 -0700)]
Btrfs: fix memory leak in do_walk_down
The extent buffer 'next' needs to be free'd conditionally.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit e0edba2e5a90e41757f6c92bf5e4e2048b463c59)
Chris Mason [Tue, 6 Sep 2016 12:37:40 +0000 (05:37 -0700)]
Btrfs: remove root_log_ctx from ctx list before btrfs_sync_log returns
We use a btrfs_log_ctx structure to pass information into the
tree log commit, and get error values out. It gets added to a per
log-transaction list which we walk when things go bad.
Commit d1433debe added an optimization to skip waiting for the log
commit, but didn't take root_log_ctx out of the list. This
patch makes sure we remove things before exiting.
Signed-off-by: Chris Mason <clm@fb.com> Fixes: d1433debe7f4346cf9fc0dafc71c3137d2a97bc4
cc: stable@vger.kernel.org # 3.15+
(cherry picked from commit cbd60aa7cd17d81a434234268c55192862147439)
Liu Bo [Thu, 21 Jul 2016 00:44:12 +0000 (17:44 -0700)]
Btrfs: fix memory leak of block group cache
While processing delayed refs, we may update block group's statistics
and attach it to cur_trans->dirty_bgs, and later writing dirty block
groups will process the list, which happens during
btrfs_commit_transaction().
For whatever reason, the transaction is aborted and dirty_bgs
is not processed in cleanup_transaction(), we end up with memory leak
of these dirty block group cache.
Since btrfs_start_dirty_block_groups() doesn't make it go to the commit
critical section, this also adds the cleanup work inside it.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit de26dfdea8048148f6faec06387cee88cc5a69b3)
dd if=/dev/zero of=$MNT/test bs=1 count=2048 &
btrfs subvolume snapshot -r $MNT $MNT/test_snap &
wait
--
We can see dd failed on NO_SPACE.
Reason:
__btrfs_buffered_write should run cow write when no_cow impossible,
and current code is designed with above logic.
But check_can_nocow() have 2 type of return value(0 and <0) on
can_not_no_cow, and current code only continue write on first case,
the second case happened in doing subvolume.
Fix:
Continue write when check_can_nocow() return 0 and <0.
Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b5282220fdd4a1e39b59a28fd499d03f2cb0c056)
Liu Bo [Fri, 29 Jul 2016 17:57:55 +0000 (10:57 -0700)]
Btrfs: remove BUG() in raid56
This BUG() has been triggered by a fuzz testing image, which contains
an invalid chunk type, ie. a single stripe chunk has the raid6 type.
Btrfs can handle this gracefully by returning -EIO, so besides using
btrfs_warn to give us more debugging information rather than a single
BUG(), we can return error properly.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
(cherry picked from commit 904df836f492713490d5cb2e8c24ddc9a76d2ed7)
Wei Yongjun [Fri, 17 Jun 2016 17:20:40 +0000 (17:20 +0000)]
Btrfs: fix error return code in btrfs_init_test_fs()
Fix to return a negative error code from the kern_mount() error handling
case instead of 0(ret is set to 0 by register_filesystem), as done
elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 04e1b65af2085d4102b2b5d2fd1e050f8ee63092)
projects / linux / log