Qu Wenruo [Wed, 1 Aug 2018 02:37:16 +0000 (10:37 +0800)]
btrfs: Check that each block group has corresponding chunk at mount time
A crafted btrfs image with incorrect chunk<->block group mapping will
trigger a lot of unexpected things as the mapping is essential.
Although the problem can be caught by block group item checker
added in "btrfs: tree-checker: Verify block_group_item", it's still not
sufficient. A sufficiently valid block group item can pass the check
added by the mentioned patch but could fail to match the existing chunk.
This patch will add extra block group -> chunk mapping check, to ensure
we have a completely matching (start, len, flags) chunk for each block
group at mount time.
Here we reuse the original helper find_first_block_group(), which is
already doing the basic bg -> chunk checks, adding further checks of the
start/len and type flags.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199837 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
When doing an incremental send, if we have a file in the parent snapshot
that has prealloc extents beyond EOF and in the send snapshot it got a
hole punch that partially covers the prealloc extents, the send stream,
when replayed by a receiver, can result in a file that has a size bigger
than it should and filled with zeroes past the correct EOF.
This issue actually happens only since commit ffa7c4296e93 ("Btrfs: send,
do not issue unnecessary truncate operations"), but before that commit we
were issuing a write operation full of zeroes (to "punch" a hole) which
was extending the file size beyond the correct value and then immediately
issue a truncate operation to the correct size and undoing the previous
write operation. Since the send protocol does not support fallocate, for
extent preallocation and hole punching, fix this by not even attempting
to send a "hole" (regular write full of zeroes) if it starts at an offset
greater then or equals to the file's size. This approach, besides being
much more simple then making send issue the truncate operation, adds the
benefit of avoiding the useless pair of write of zeroes and truncate
operations, saving time and IO at the receiver and reducing the size of
the send stream.
A test case for fstests follows soon.
Fixes: ffa7c4296e93 ("Btrfs: send, do not issue unnecessary truncate operations") CC: stable@vger.kernel.org # 4.17+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Al Viro [Sun, 29 Jul 2018 22:04:51 +0000 (23:04 +0100)]
btrfs: simplify btrfs_iget
Don't open-code iget_failed(), don't bother with btrfs_free_path(NULL),
move handling of positive return values of btrfs_lookup_inode() from
btrfs_read_locked_inode() to btrfs_iget() and kill now obviously
pointless ASSERT() in there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Al Viro [Sun, 29 Jul 2018 22:04:50 +0000 (23:04 +0100)]
btrfs: lift make_bad_inode into btrfs_iget
We don't need to check is_bad_inode() after the call of
btrfs_read_locked_inode() - it's exactly the same as checking return
value for being non-zero.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Al Viro [Sun, 29 Jul 2018 22:04:46 +0000 (23:04 +0100)]
btrfs: simplify IS_ERR/PTR_ERR checks
IS_ERR(p) && PTR_ERR(p) == n is a weird way to spell p == ERR_PTR(n).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
[ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
Al Viro [Sun, 29 Jul 2018 22:04:45 +0000 (23:04 +0100)]
btrfs: btrfs_iget never returns an is_bad_inode inode
Just get rid of pointless checks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: replace: Reset on-disk dev stats value after replace
on-disk devs stats value is updated in btrfs_run_dev_stats(),
which is called during commit transaction, if device->dev_stats_ccnt
is not zero.
Since current replace operation does not touch dev_stats_ccnt,
on-disk dev stats value is not updated. Therefore "btrfs device stats"
may return old device's value after umount/mount
(Example: See "btrfs ins dump-t -t DEV $DEV" after btrfs/100 finish).
Fix this by just incrementing dev_stats_ccnt in
btrfs_dev_replace_finishing() when replace is succeeded and this will
update the values.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Lu Fengqi [Wed, 1 Aug 2018 03:32:31 +0000 (11:32 +0800)]
btrfs: Remove redundant btrfs_release_path from btrfs_unlink_subvol
Although it is safe to call this on already released paths with no locks
held or extent buffers, removing the redundant btrfs_release_path is
reasonable.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 24 Jul 2018 10:54:04 +0000 (11:54 +0100)]
Btrfs: fix send failure when root has deleted files still open
The more common use case of send involves creating a RO snapshot and then
use it for a send operation. In this case it's not possible to have inodes
in the snapshot that have a link count of zero (inode with an orphan item)
since during snapshot creation we do the orphan cleanup. However, other
less common use cases for send can end up seeing inodes with a link count
of zero and in this case the send operation fails with a ENOENT error
because any attempt to generate a path for the inode, with the purpose
of creating it or updating it at the receiver, fails since there are no
inode reference items. One use case it to use a regular subvolume for
a send operation after turning it to RO mode or turning a RW snapshot
into RO mode and then using it for a send operation. In both cases, if a
file gets all its hard links deleted while there is an open file
descriptor before turning the subvolume/snapshot into RO mode, the send
operation will encounter an inode with a link count of zero and then
fail with errno ENOENT.
# Turn the second snapshot to RW mode and delete file foo while
# holding an open file descriptor on it.
$ btrfs property set /mnt/snap2 ro false
$ exec 73</mnt/snap2/foo
$ unlink /mnt/snap2/foo
# Set the second snapshot back to RO mode and do an incremental send.
$ btrfs property set /mnt/snap2 ro true
$ btrfs send -f /tmp/inc.send -p /mnt/snap1 /mnt/snap2
At subvol /mnt/snap2
ERROR: send ioctl failed with -2: No such file or directory
So fix this by ignoring inodes with a link count of zero if we are either
doing a full send or if they do not exist in the parent snapshot (they
are new in the send snapshot), and unlink all paths found in the parent
snapshot when doing an incremental send (and ignoring all other inode
items, such as xattrs and extents).
A test case for fstests follows soon.
CC: stable@vger.kernel.org # 4.4+ Reported-by: Martin Wilck <martin.wilck@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Fri, 20 Jul 2018 09:59:06 +0000 (10:59 +0100)]
Btrfs: fix mount failure after fsync due to hard link recreation
If we end up with logging an inode reference item which has the same name
but different index from the one we have persisted, we end up failing when
replaying the log with an errno value of -EEXIST. The error comes from
btrfs_add_link(), which is called from add_inode_ref(), when we are
replaying an inode reference item.
Example scenario where this happens:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/foo
$ ln /mnt/foo /mnt/bar
$ sync
# Rename the first hard link (foo) to a new name and rename the second
# hard link (bar) to the old name of the first hard link (foo).
$ mv /mnt/foo /mnt/qwerty
$ mv /mnt/bar /mnt/foo
# Create a new file, in the same parent directory, with the old name of
# the second hard link (bar) and fsync this new file.
# We do this instead of calling fsync on foo/qwerty because if we did
# that the fsync resulted in a full transaction commit, not triggering
# the problem.
$ touch /mnt/bar
$ xfs_io -c "fsync" /mnt/bar
<power fail>
$ mount /dev/sdb /mnt
mount: mount /dev/sdb on /mnt failed: File exists
So fix this by checking if a conflicting inode reference exists (same
name, same parent but different index), removing it (and the associated
dir index entries from the parent inode) if it exists, before attempting
to add the new reference.
A test case for fstests follows soon.
CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Thu, 19 Jul 2018 14:49:51 +0000 (10:49 -0400)]
btrfs: don't leak ret from do_chunk_alloc
If we're trying to make a data reservation and we have to allocate a
data chunk we could leak ret == 1, as do_chunk_alloc() will return 1 if
it allocated a chunk. Since the end of the function is the success path
just return 0.
CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Fri, 20 Jul 2018 14:30:25 +0000 (16:30 +0200)]
btrfs: merge free_fs_root helpers
The exported helper just calls the static one. There's no obvious reason
to have them separate eg. for performance reasons where the static one
could be better optimized in the same unit. There's a slight decrease in
code size and stack consumption.
David Sterba [Fri, 20 Jul 2018 14:30:20 +0000 (16:30 +0200)]
btrfs: dev-replace: remove unused members of btrfs_dev_replace
Lock owner and nesting level have been unused since day 1, probably
copy&pasted from the extent_buffer locking scheme without much thinking.
The locking of device replace is simpler and does not need any lock
nesting.
David Sterba [Fri, 20 Jul 2018 14:30:18 +0000 (16:30 +0200)]
btrfs: remove unused member btrfs_root::name
Added in 58176a9604c ("Btrfs: Add per-root block accounting and sysfs
entries") in 2007, the roots had names exported in sysfs. The code
was commented out in 4df27c4d5cc1dda54ed ("Btrfs: change how subvolumes
are organized") and cleaned by 182608c8294b5fe9 ("btrfs: remove old
unused commented out code").
Adam Borowski [Tue, 17 Jul 2018 22:08:59 +0000 (00:08 +0200)]
btrfs: allow defrag on a file opened read-only that has rw permissions
Requiring a read-write descriptor conflicts both ways with exec,
returning ETXTBSY whenever you try to defrag a program that's currently
being run, or causing intermittent exec failures on a live system being
defragged.
As defrag doesn't change the file's contents in any way, there's no
reason to consider it a rw operation. Thus, let's check only whether
the file could have been opened rw. Such access control is still needed
as currently defrag can use extra disk space, and might trigger bugs.
We return EINVAL when the request is invalid; here it's ok but merely
the user has insufficient privileges. Thus, the EPERM return value
reflects the error better -- as discussed in the identical case for
dedupe.
According to codesearch.debian.net, no userspace program distinguishes
these values beyond strerror().
Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: David Sterba <dsterba@suse.com>
[ fold the EPERM patch from Adam ] Signed-off-by: David Sterba <dsterba@suse.com>
If iput() is called on that same inode, evict() will wait for writeback
forever.
btrfs_write_inode() was originally added way back in 4730a4bc5bf3
("btrfs_dirty_inode") to support O_SYNC writes. However, ->write_inode()
hasn't been used for O_SYNC since 148f948ba877 ("vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode"), so
btrfs_write_inode() is actually unnecessary (and leads to a bunch of
unnecessary commits). Get rid of it, which also gets rid of the
deadlock.
CC: stable@vger.kernel.org # 3.2+ Signed-off-by: Josef Bacik <jbacik@fb.com>
[Omar: new commit message] Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Fri, 20 Jul 2018 16:37:50 +0000 (19:37 +0300)]
btrfs: Remove fs_info from btrfs_assign_next_active_device
It can be referenced from the passed 'device' argument which is always
a well-formed device.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 23 Jul 2018 08:10:09 +0000 (09:10 +0100)]
Btrfs: remove unused key assignment when doing a full send
At send.c:full_send_tree() we were setting the 'key' variable in the loop
while never using it later. We were also using two btrfs_key variables
to store the initial key for search and the key found in every iteration
of the loop. So remove this useless key assignment and use the same
btrfs_key variable to store the initial search key and the key found in
each iteration. This was introduced in the initial send commit but was
never used (commit 31db9f7c23fb ("Btrfs: introduce BTRFS_IOC_SEND for
btrfs send/receive").
Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Wed, 18 Jul 2018 15:36:24 +0000 (17:36 +0200)]
btrfs: unify end_io callbacks of async_submit_bio
The end_io callbacks passed to btrfs_wq_submit_bio
(btrfs_submit_bio_done and btree_submit_bio_done) are effectively the
same code, there's no point to do the indirection. Export
btrfs_submit_bio_done and call it directly.
Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Wed, 18 Jul 2018 15:31:10 +0000 (17:31 +0200)]
btrfs: remove unused member async_submit_bio::bio_flags
After splitting the start and end hooks in a758781d4b76c3 ("btrfs:
separate types for submit_bio_start and submit_bio_done"), some of
the function arguments were dropped but not removed from the structure.
Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Wed, 18 Jul 2018 15:31:19 +0000 (17:31 +0200)]
btrfs: remove unused member async_submit_bio::fs_info
Introduced by c6100a4b4e3d1 ("Btrfs: replace tree->mapping with
tree->private_data") to be used in run_one_async_done where it got
unused after 736cd52e0c720103 ("Btrfs: remove nr_async_submits and
async_submit_draining").
Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 27 Jun 2018 13:38:24 +0000 (16:38 +0300)]
btrfs: Rename EXTENT_BUFFER_DUMMY to EXTENT_BUFFER_UNMAPPED
EXTENT_BUFFER_DUMMY is an awful name for this flag. Buffers which have
this flag set are not in any way dummy. Rather, they are private in the
sense that are not mapped and linked to the global buffer tree. This
flag has subtle implications to the way free_extent_buffer works for
example, as well as controls whether page->mapping->private_lock is held
during extent_buffer release. Pages for an unmapped buffer cannot be
under io, nor can they be written by a 3rd party so taking the lock is
unnecessary.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com>
[ EXTENT_BUFFER_UNMAPPED, update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 27 Jun 2018 13:38:23 +0000 (16:38 +0300)]
btrfs: Document locking requirement via lockdep_assert_held
Remove stale comment since there is no longer an eb->eb_lock and
document the locking expectation with a lockdep_assert_held statement.
No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Thu, 19 Jul 2018 15:24:32 +0000 (17:24 +0200)]
btrfs: rename btrfs_release_extent_buffer_page
The function used to release one page (and always the first one), but
not anymore since a50924e3a4d7fccb0ecfbd4 ("btrfs: drop constant param
from btrfs_release_extent_buffer_page"). Update the name and comment.
Nikolay Borisov [Wed, 27 Jun 2018 13:38:22 +0000 (16:38 +0300)]
btrfs: Refactor loop in btrfs_release_extent_buffer_page
The purpose of the function is to free all the pages comprising an
extent buffer. This can be achieved with a simple for loop rather than
the slightly more involved 'do {} while' construct. So rewrite the
loop using a 'for' construct. Additionally we can never have an
extent_buffer that has 0 pages so remove the check for index == 0. No
functional changes.
The reversed order used to have a meaning in the past where the first
page served as a blocking point for several callers. See eg 4f2de97acee6532b36dd6e99 ("Btrfs: set page->private to the eb").
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 4 Jul 2018 07:24:52 +0000 (10:24 +0300)]
btrfs: Reword dodgy comments in alloc_extent_buffer
Commit eb14ab8ed24a ("Btrfs: fix page->private races") fixed a genuine
race between extent buffer initialisation and btree_releasepage.
Unfortunately as the code has evolved the comments weren't changed which
made them slightly wrong and they weren't very clear in the fist place.
Fix this by (hopefully) rewording them in a more approachable manner.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 4 Jul 2018 07:24:51 +0000 (10:24 +0300)]
btrfs: Simplify page unlocking in alloc_extent_buffer
Current version of the page unlocking code was added in 727011e07cbd ("Btrfs: allow metadata blocks larger than the page size")
but even in this commit that particular flag was never used per-se. In
fact, btrfs only uses PageChecked for data pages to identify pages
which have been dirtied but don't have ORDERED bit set. For more
information see 247e743cbe6e ("Btrfs: Use async helpers to deal with
pages that have been improperly dirtied").
However, this doesn't apply to extent buffer pages. The important bit
here is that the pages are unlocked AFTER the extent buffer has been
properly recorded in the radix tree to avoid races with
btree_releasepage. Let's exploit this fact and simplify the page
unlocking sequence by unlocking the pages in-order and removing the
redundant PageChecked flag setting/clearing.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: scrub: cleanup the remaining nodatasum fixup code
Remove the remaining code that misused the page cache pages during
device replace and could cause data corruption for compressed nodatasum
extents. Such files do not normally exist but there's a bug that allows
this combination and the corruption was exposed by device replace fixup
code.
Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Fri, 13 Jul 2018 18:46:30 +0000 (20:46 +0200)]
btrfs: refactor block group replication factor calculation to a helper
There are many places that open code the duplicity factor of the block
group profiles, create a common helper. This can be easily extended for
more copies.
Rename btrfs_parse_early_options() to btrfs_parse_device_options(). As
btrfs_parse_early_options() parses the -o device options and scan the
device provided. So this rename specifies its action. Also the function
name is in line with btrfs_parse_subvol_options().
No functional changes.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Lu Fengqi [Tue, 17 Jul 2018 08:58:22 +0000 (16:58 +0800)]
btrfs: qgroup: cleanup the unused srcroot from btrfs_qgroup_inherit
Since commit 0b246afa62b0 ("btrfs: root->fs_info cleanup, add fs_info
convenience variables"), the srcroot is no longer used to get
fs_info::nodesize. In fact, it can be dropped after commit 707e8a071528
("btrfs: use nodesize everywhere, kill leafsize").
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Wed, 18 Apr 2018 07:27:57 +0000 (10:27 +0300)]
btrfs: Rewrite retry logic in do_chunk_alloc
do_chunk_alloc implements logic to detect whether there is currently
pending chunk allocation (by means of space_info->chunk_alloc being
set) and if so it loops around to the 'again' label. Additionally,
based on the state of the space_info (e.g. whether it's full or not)
and the return value of should_alloc_chunk() it decides whether this
is a "hard" error (ENOSPC) or we can just return 0.
This patch refactors all of this:
1. Put order to the scattered ifs handling the various cases in an
easy-to-read if {} else if{} branches. This makes clear the various
cases we are interested in handling.
2. Call should_alloc_chunk only once and use the result in the
if/else if constructs. All of this is done under space_info->lock, so
even before multiple calls of should_alloc_chunk were unnecessary.
3. Rewrite the "do {} while()" loop currently implemented via label
into an explicit loop construct.
4. Move the mutex locking for the case where the caller is the one doing
the allocation. For the case where the caller needs to wait a concurrent
allocation, introduce a pair of mutex_lock/mutex_unlock to act as a
barrier and reword the comment.
5. Switch local vars to bool type where pertinent.
All in all this shouldn't introduce any functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: use customized batch size for total_bytes_pinned
In commit b150a4f10d878 ("Btrfs: use a percpu to keep track of possibly
pinned bytes") we use total_bytes_pinned to track how many bytes we are
going to free in this transaction. When we are close to ENOSPC, we check it
and know if we can make the allocation by commit the current transaction.
For every data/metadata extent we are going to free, we add
total_bytes_pinned in btrfs_free_extent() and btrfs_free_tree_block(), and
release it in unpin_extent_range() when we finish the transaction. So this
is a variable we frequently update but rarely read - just the suitable
use of percpu_counter. But in previous commit we update total_bytes_pinned
by default 32 batch size, making every update essentially a spin lock
protected update. Since every spin lock/unlock operation involves syncing
a globally used variable and some kind of barrier in a SMP system, this is
more expensive than using total_bytes_pinned as a simple atomic64_t.
So fix this by using a customized batch size. Since we only read
total_bytes_pinned when we are close to ENOSPC and fail to allocate new
chunk, we can use a really large batch size and have nearly no penalty
in most cases.
[Test]
We tested the patch on a 4-cores x86 machine:
1. fallocate a 16GiB size test file
2. take snapshot (so all following writes will be COW)
3. run a 180 sec, 4 jobs, 4K random write fio on test file
We also added a temporary lockdep class on percpu_counter's spin lock
used by total_bytes_pinned to track it by lock_stat.
[Results]
unpatched:
lock_stat version 0.4
-----------------------------------------------------------------------
class name con-bounces contentions
waittime-min waittime-max waittime-total waittime-avg acq-bounces
acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
[Analysis]
Since the spin lock only protects a single in-memory variable, the
contentions (number of lock acquisitions that had to wait) in both
unpatched and patched version are low. But when we see acquisitions and
acq-bounces, we get much lower counts in patched version. Here the most
important metric is acq-bounces. It means how many times the lock gets
transferred between different cpus, so the patch can really reduce
cacheline bouncing of spin lock (also the global counter of percpu_counter)
in a SMP system.
Fixes: b150a4f10d878 ("Btrfs: use a percpu to keep track of possibly pinned bytes") Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: use correct compare function of dirty_metadata_bytes
We use customized, nodesize batch value to update dirty_metadata_bytes.
We should also use batch version of compare function or we will easily
goto fast path and get false result from percpu_counter_compare().
Fixes: e2d845211eda ("Btrfs: use percpu counter for dirty metadata count") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: return device pointer from btrfs_scan_one_device
Return device pointer (with the IS_ERR semantics) from
btrfs_scan_one_device so we don't have to return in through pointer.
And since btrfs_fs_devices can be obtained from btrfs_device, return that.
Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com>
[ fixed conflics after recent changes to btrfs_scan_one_device ] Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: make fs_devices a local variable in btrfs_parse_early_options
fs_devices is always passed to btrfs_scan_one_device which overrides it.
In the call stack below fs_devices is passed to btrfs_scan_one_device
from btrfs_mount_root. In btrfs_mount_root the output fs_devices of
this call stack is not used.
David Sterba [Tue, 19 Jun 2018 16:04:07 +0000 (18:04 +0200)]
btrfs: fix mount and ioctl device scan ioctl race
Technically this extends the critical section covered by uuid_mutex to:
- parse early mount options -- here we can call device scan on paths
that can be passed as 'device=/dev/...'
- scan the device passed to mount
- open the devices related to the fs_devices -- this increases
fs_devices::opened
The race can happen when mount calls one of the scans and there's
another one called eg. by mkfs or 'btrfs dev scan':
Mount Scan
----- ----
scan_one_device (dev1, fsid1)
scan_one_device (dev2, fsid1)
add the device
free stale devices
fsid1 fs_devices::opened == 0
find fsid1:dev1
free fsid1:dev1
if it's the last one,
free fs_devices of fsid1
too
open_devices (dev1, fsid1)
dev1 not found
When fixed, the uuid mutex will make sure that mount will increase
fs_devices::opened and this will not be touched by the racing scan
ioctl.
David Sterba [Tue, 19 Jun 2018 15:09:47 +0000 (17:09 +0200)]
btrfs: lift uuid_mutex to callers of btrfs_open_devices
Prepartory work to fix race between mount and device scan.
The callers will have to manage the critical section, eg. mount wants to
scan and then call btrfs_open_devices without the ioctl scan walking in
and modifying the fs devices in the meantime.
Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 19 Jun 2018 14:37:36 +0000 (16:37 +0200)]
btrfs: lift uuid_mutex to callers of btrfs_scan_one_device
Prepartory work to fix race between mount and device scan.
The callers will have to manage the critical section, eg. mount wants to
scan and then call btrfs_open_devices without the ioctl scan walking in
and modifying the fs devices in the meantime.
Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 29 May 2018 09:23:20 +0000 (17:23 +0800)]
btrfs: use device_list_mutex when removing stale devices
btrfs_free_stale_devices() finds a stale (not opened) device matching
path in the fs_uuid list. We are already under uuid_mutex so when we
check for each fs_devices, hold the device_list_mutex too.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 29 May 2018 07:33:08 +0000 (15:33 +0800)]
btrfs: rename local devices for fs_devices in btrfs_free_stale_devices(
Over the years we named %fs_devices and %devices to represent the
struct btrfs_fs_devices and the struct btrfs_device. So follow the same
scheme here too. No functional changes.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 29 May 2018 06:10:20 +0000 (14:10 +0800)]
btrfs: extend locked section when adding a new device in device_list_add
Make sure the device_list_lock is held the whole time:
* when the device is being looked up
* new device is initialized and put to the list
* the list counters are updated (fs_devices::opened, fs_devices::total_devices)
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ update changelog ] Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay Borisov [Fri, 29 Jun 2018 05:26:05 +0000 (08:26 +0300)]
btrfs: close devices without offloading to a temporary list
Since commit 88c14590cdd6 ("btrfs: use RCU in btrfs_show_devname for
device list traversal") btrfs_show_devname no longer takes
device_list_mutex. As such the deadlock that 0ccd05285e7f ("btrfs: fix a
possible umount deadlock") aimed to fix no longer exists, we can free
the devices immediatelly and remove the code that does the pending work.
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com>
[ update changelog ] Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: Remove unused function btrfs_account_dev_extents_size
This function is not used since the alloc_start parameter has been
obsoleted in commit 0d0c71b317207082856 ("btrfs: obsolete and remove
mount option alloc_start").
Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: fix in-memory value of total_devices after seed device deletion
In case of deleting the seed device the %cur_devices (seed) and the
%fs_devices (parent) are different. Now, as the parent
fs_devices::total_devices also maintains the total number of devices
including the seed device, so decrement its in-memory value for the
successful seed delete. We are already updating its corresponding
on-disk btrfs_super_block::number_devices value.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Commit 5d23515be669 ("btrfs: Move qgroup rescan on quota enable to
btrfs_quota_enable") not only resulted in an easier to follow code but
it also introduced a subtle bug. It changed the timing when the initial
transaction rescan was happening:
- before the commit: it would happen after transaction commit had occured
- after the commit: it might happen before the transaction was committed
This results in failure to correctly rescan the quota since there could
be data which is still not committed on disk.
This patch aims to fix this by moving the transaction creation/commit
inside btrfs_quota_enable, which allows to schedule the quota commit
after the transaction has been committed.
Fixes: 5d23515be669 ("btrfs: Move qgroup rescan on quota enable to btrfs_quota_enable") Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Link: https://marc.info/?l=linux-btrfs&m=152999289017582 Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Fri, 29 Jun 2018 08:57:10 +0000 (10:57 +0200)]
btrfs: raid56: catch errors from full_stripe_write
Add fall-back code to catch failure of full_stripe_write. Proper error
handling from inside run_plug would need more code restructuring as it's
called at arbitrary points by io scheduler.
projects / kernel.git / log