The correct lock order is uuid_mutex -> volume_mutex -> chunk_mutex,
but when we mount a filesystem which has backing seed devices, we have
this lock chain:
open_ctree()
lock(chunk_mutex);
read_chunk_tree();
read_one_dev();
open_seed_devices();
lock(uuid_mutex);
and then we hit a lockdep splat.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
A bug was triggered while using seed device:
# mkfs.btrfs /dev/loop1
# btrfstune -S 1 /dev/loop1
# mount -o /dev/loop1 /mnt
# btrfs dev add /dev/loop2 /mnt
btrfs: block rsv returned -28
------------[ cut here ]------------
WARNING: at fs/btrfs/extent-tree.c:5969 btrfs_alloc_free_block+0x166/0x396 [btrfs]()
...
Call Trace:
...
[<f7b7c31c>] btrfs_cow_block+0x101/0x147 [btrfs]
[<f7b7eaa6>] btrfs_search_slot+0x1b8/0x55f [btrfs]
[<f7b7f844>] btrfs_insert_empty_items+0x42/0x7f [btrfs]
[<f7b7f8c1>] btrfs_insert_item+0x40/0x7e [btrfs]
[<f7b8ac02>] btrfs_make_block_group+0x243/0x2aa [btrfs]
[<f7bb3f53>] __btrfs_alloc_chunk+0x672/0x70e [btrfs]
[<f7bb41ff>] init_first_rw_device+0x77/0x13c [btrfs]
[<f7bb5a62>] btrfs_init_new_device+0x664/0x9fd [btrfs]
[<f7bbb65a>] btrfs_ioctl+0x694/0xdbe [btrfs]
[<c04f55f7>] do_vfs_ioctl+0x496/0x4cc
[<c04f5660>] sys_ioctl+0x33/0x4f
[<c07b9edf>] sysenter_do_call+0x12/0x38
---[ end trace 906adac595facc7d ]---
Since seed device is readonly, there's no usable space in the filesystem.
Afterwards we add a sprout device to it, and the kernel creates a METADATA
block group and a SYSTEM block group where comes free space we can reserve,
but we still get revervation failure because the global block_rsv hasn't
been updated accordingly.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
There are various bugs in block group trimming:
- It may trim from offset smaller than user-specified offset.
- It may trim beyond user-specified range.
- It may leak free space for extents smaller than specified minlen.
- It may truncate the last trimmed extent thus leak free space.
- With mixed extents+bitmaps, some extents may not be trimmed.
- With mixed extents+bitmaps, some bitmaps may not be trimmed (even
none will be trimmed). Even for those trimmed, not all the free space
in the bitmaps will be trimmed.
I rewrite btrfs_trim_block_group() and break it into two functions.
One is to trim extents only, and the other is to trim bitmaps only.
Before patching:
# fstrim -v /mnt/
/mnt/: 1496465408 bytes were trimmed
After patching:
# fstrim -v /mnt/
/mnt/: 2193768448 bytes were trimmed
And this matches the total free space:
# btrfs fi df /mnt
Data: total=3.58GB, used=1.79GB
System, DUP: total=8.00MB, used=4.00KB
System: total=4.00MB, used=0.00
Metadata, DUP: total=205.12MB, used=97.14MB
Metadata: total=8.00MB, used=0.00
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
For btrfs raid, while discarding a range of space, we'll need to know
the start offset and length to discard for each device, and it's done
in btrfs_map_block().
However the calculation is a bit complex for raid0 and raid10, so I
reimplement it based on a fact that:
dev1 dev2 dev3 (raid0)
-----------------------------------
s0 s3 s6 s1 s4 s7 s2 s5
Each device has (total_stripes / nr_dev) stripes, or plus one.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
We pre-allocate a btrfs bio with fixed size, and then may re-allocate
memory if we find stripes are bigger than the fixed size. But this
pre-allocation is not necessary.
Also we don't have to calcuate the stripe number twice.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
I got this while running xfstests:
[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600
We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the latter can be obtained from the former (by looking as ->tree_root)
just as cheaply as we currently are doing the other way round.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and don't bother with it after btrfs_fill_super() failure -
->kill_sb() (unlike ->put_super()) will be called even if we
have not got non-NULL ->s_root.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We do not (fortunately) modify ->s_fs_info of superblock on the fly in
btrfs_fill_super(); apparent assignment is a no-op.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It returns either ERR_PTR(-ve) or sb->s_fs_info. The latter can
be found by caller just as well, TYVM, no need to return it. Just
return -ve or 0...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
close_ctree() uses a weird mix of accesses to root->fs_info and
its value at the beginning of function stored in local variable.
Since ->fs_info *never* changes, let's just use the local variable
to avoid confusion.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A new helper: btrfs_alloc_root(fs_info); allocates btrfs_root
and sets ->fs_info. All places allocating the suckers converted
to it. At that point we *never* reassign ->fs_info of btrfs_root;
it's set before anyone sees the address of newly allocated
struct btrfs_root and never assigned anywhere else.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
move assignments to ->fs_info in open_ctree() up, to the place
just after the original allocations. Assignment for tree_root
becomes a no-op - we'd obtained fs_info from tree_root->fs_info
in the first place.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pathname resolution under a global mutex, taken on some paths in ->mount()
is a Bad Idea(tm) - think what happens if said pathname resolution triggers
automount of some btrfs instance and walks into attempt to grab the same
mutex. Deadlock - we are waiting for daemon to finish walking the path,
daemon is waiting for us to release the mutex...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Do *NOT* skip doomed superblocks in btrfs_test_super(); we want
sget() to wait for their shutdown to complete. Since we don't
mutilate ->s_fs_info in ->put_super() anymore (or free what it
used to point to until the superblock is past being findable
by sget()), we can just DTRT there and report a match.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and move free_fs_info() to that, out of ->put_super(). Do NOT
set ->s_fs_info to NULL in the latter; we need it for sget() to
be able to see and wait for fs in the middle of umount if we get a
mount/umount race.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need fs_info and root to live until the moment when the victim
superblock leaves the list, so we need to postpone free_fs_info()
until after ->put_super(). The call is buried in close_ctree(),
though, so we need to lift it into the callers (including
btrfs_put_super()) first.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
Kconfig: acpi: Fix typo in comment.
misc latin1 to utf8 conversions
devres: Fix a typo in devm_kfree comment
btrfs: free-space-cache.c: remove extra semicolon.
fat: Spelling s/obsolate/obsolete/g
SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
tools/power turbostat: update fields in manpage
mac80211: drop spelling fix
types.h: fix comment spelling for 'architectures'
typo fixes: aera -> area, exntension -> extension
devices.txt: Fix typo of 'VMware'.
sis900: Fix enum typo 'sis900_rx_bufer_status'
decompress_bunzip2: remove invalid vi modeline
treewide: Fix comment and string typo 'bufer'
hyper-v: Update MAINTAINERS
treewide: Fix typos in various parts of the kernel, and fix some comments.
clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
leds: Kconfig: Fix typo 'D2NET_V2'
sound: Kconfig: drop unknown symbol ARCH_CLPS7500
...
Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
PM / Hibernate: Implement compat_ioctl for /dev/snapshot
PM / Freezer: fix return value of freezable_schedule_timeout_killable()
PM / shmobile: Allow the A4R domain to be turned off at run time
PM / input / touchscreen: Make st1232 use device PM QoS constraints
PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
PM / shmobile: Remove the stay_on flag from SH7372's PM domains
PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
ARM: S3C64XX: Implement basic power domain support
PM / shmobile: Use common always on power domain governor
...
Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
Parameterize clusters on minimum total size, minimum chunk size and
minimum contiguous size for at least one chunk, without limits on
cluster, window or gap sizes. Don't tolerate any fragmentation for
SSD_SPREAD; accept it for metadata, but try to keep data dense.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We store the allocation start and length twice in ins, once right
after the other, but with intervening calls that may prevent the
duplicate from being optimized out by the compiler. Remove one of the
assignments.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Since the clustered allocation may be taking extents from a different
block group, there's no point in spin-locking and testing the current
block group free space before attempting to allocate space from a
cluster, even more so when we might refrain from even trying the
cluster in the current block group because, after the cluster was set
up, not enough free space remained. Furthermore, cluster creation
attempts fail fast when the block group doesn't have enough free
space, so the test was completely superfluous.
I've move the free space test past the cluster allocation attempt,
where it is more useful, and arranged for a cluster in the current
block group to be released before trying an unclustered allocation,
when we reach the LOOP_NO_EMPTY_SIZE stage, so that the free space in
the cluster stands a chance of being combined with additional free
space in the block group so as to succeed in the allocation attempt.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The chunk allocation code has tried to keep a pretty tight lid on creating new
metadata chunks. This is partially because in the past the reservation
code didn't give us an accurate idea of how much space was being used.
The new code is much more accurate, so we're able to get rid of some of these
checks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs tries to batch extent allocation tree changes to improve performance
and reduce metadata trashing. But it doesn't allocate new metadata chunks
while it is doing allocations for the extent allocation tree.
This commit changes the delayed refence code to do chunk allocations if we're
getting low on room. It prevents crashes and improves performance.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There's code in btrfs_get_extent that should never be used. This patch turns
a WARN_ON(1) into a BUG(), hoping we can remove the transaction code from
btrfs_get_extent soon.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
The old backref iteration code could only safely be used on commit roots.
Besides this limitation, it had bugs in finding the roots for these
references. This commit replaces large parts of it by btrfs_find_all_roots()
which a) really finds all roots and the correct roots, b) works correctly
under heavy file system load, c) considers delayed refs.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
This function gets a byte number (a data extent), collects all the leafs
pointing to it and walks up the trees to find all fs roots pointing to those
leafs. It also returns the list of all leafs pointing to that extent.
It does proper locking for the involved trees, can be used on busy file
systems and honors delayed refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Now that we may be holding back delayed refs for a limited period, we
might end up having no runnable delayed refs. Without this commit, we'd
do busy waiting in that thread until another (runnable) ref arives.
Instead, we're detecting this situation and use a waitqueue, such that
we only try to run more refs after
a) another runnable ref was added or
b) delayed refs are no longer held back
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
When processing a delayed ref, first check if there are still old refs in
the process of being added. If so, put this ref back to the tree. To avoid
looping on this ref, choose a newer one in the next loop.
btrfs_find_ref_cluster has to take care of that.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Sequence numbers are needed to reconstruct the backrefs of a given extent to
a certain point in time. The total set of backrefs consist of the set of
backrefs recorded on disk plus the enqueued delayed refs for it that existed
at that moment.
This patch also adds a list that records all delayed refs which are
currently in the process of being added.
When walking all refs of an extent in btrfs_find_all_roots(), we freeze the
current state of delayed refs, honor anythinh up to this point and prevent
processing newer delayed refs to assert consistency.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
This patch adds the possibilty to read-lock an extent even if it is already
write-locked from the same thread. btrfs_find_all_roots() needs this
capability.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
