Commit Graph

5189 Commits

Author SHA1 Message Date
Al Viro 5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds 2101ae4289 Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull more btrfs updates from Chris Mason:
 "These are mostly fixes that we've been testing, but also we grabbed
  and tested a few small cleanups that had been on the list for a while.

  Zhao Lei's patchset also fixes some early ENOSPC buglets"

* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (21 commits)
  btrfs: raid56: Use raid_write_end_io for scrub
  btrfs: Remove unnecessary ClearPageUptodate for raid56
  btrfs: use rbio->nr_pages to reduce calculation
  btrfs: Use unified stripe_page's index calculation
  btrfs: Fix calculation of rbio->dbitmap's size calculation
  btrfs: Fix no_space in write and rm loop
  btrfs: merge functions for wait snapshot creation
  btrfs: delete unused argument in btrfs_copy_from_user
  btrfs: Use direct way to determine raid56 write/recover mode
  btrfs: Small cleanup for get index_srcdev loop
  btrfs: Enhance chunk validation check
  btrfs: Enhance super validation check
  Btrfs: fix deadlock running delayed iputs at transaction commit time
  Btrfs: fix typo in log message when starting a balance
  btrfs: remove duplicate const specifier
  btrfs: initialize the seq counter in struct btrfs_device
  Btrfs: clean up an error code in btrfs_init_space_info()
  btrfs: fix iterator with update error in backref.c
  Btrfs: fix output of compression message in btrfs_parse_options()
  Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots
  ...
2016-01-22 11:49:21 -08:00
Zhao Lei a6111d11b8 btrfs: raid56: Use raid_write_end_io for scrub
No need to create additional end_io function for scrub, it increased
code size and introduced some un-unified lines, as:
raid_write_parity_end_io():
        int err = bio->bi_error;
        if (bio->bi_error)
raid_write_end_io():
        int err = bio->bi_error;
        if (err)

This patch combines them.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:18 -08:00
Zhao Lei 748f4ef4c6 btrfs: Remove unnecessary ClearPageUptodate for raid56
PageUptodate flag already initialized to 0 for new page,
no need to set it again.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:17 -08:00
Zhao Lei 915e22903c btrfs: use rbio->nr_pages to reduce calculation
We can use rbio->stripe_npages to reduce unnecessary calculation in
many code place.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:16 -08:00
Zhao Lei b7178a5f03 btrfs: Use unified stripe_page's index calculation
We are using different index calculation method for stripe_page in
current code:
1: (rbio->stripe_len / PAGE_CACHE_SIZE) * stripe_index + page_index
2: DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE) * stripe_index + page_index
3: DIV_ROUND_UP(rbio->stripe_len * stripe_index, PAGE_CACHE_SIZE) + page_index
...

They can get same result when stripe_len align to PAGE_CACHE_SIZE,
this is why current code can work, intruduce and use a common function
for calculation is a better choose.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:16 -08:00
Zhao Lei bfca9a6d4b btrfs: Fix calculation of rbio->dbitmap's size calculation
Current code is trying to calculate rbio->dbitmap's size to make it
align to sizeof(long), but implement haven't achived this object,
it is align to sizeof(char) instead.
This patch fixed above calculation, and use sizeof(long) instead of
fixed "8" to increate compatibility.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:15 -08:00
Zhao Lei e1746e8381 btrfs: Fix no_space in write and rm loop
I see no_space in v4.4-rc1 again in xfstests generic/102.
It happened randomly in some node only.
(one of 4 phy-node, and a kvm with non-virtio block driver)

By bisect, we can found the first-bad is:
 commit bdced438ac ("block: setup bi_phys_segments after splitting")'
But above patch only triggered the bug by making bio operation
faster(or slower).

Main reason is in our space_allocating code, we need to commit
page writeback before wait it complish, this patch fixed above
bug.

BTW, there is another reason for generic/102 fail, caused by
disable default mixed-blockgroup, I'll fix it in xfstests.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:14 -08:00
Zhao Lei 0bc19f9031 btrfs: merge functions for wait snapshot creation
wait_for_snapshot_creation() is in same group with oher two:
 btrfs_start_write_no_snapshoting()
 btrfs_end_write_no_snapshoting()

Rename wait_for_snapshot_creation() and move it into same place
with other two.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:13 -08:00
Zhao Lei ee22f0c4ec btrfs: delete unused argument in btrfs_copy_from_user
size_t write_bytes is not necessary for btrfs_copy_from_user(),
delete it.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-20 07:22:13 -08:00
Zhao Lei ad1ba2a0c4 btrfs: Use direct way to determine raid56 write/recover mode
Old code used bbio->raid_map to determine whether in raid56
write/recover operation, because we didn't't have bbio->map_type.

Now we have direct way for this condition, rid of using
the function-relative data, and make the code more readable.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:43:45 -08:00
Zhao Lei 94a97dfeb6 btrfs: Small cleanup for get index_srcdev loop
1: Adjust condition in loop to make less TAB
2: Move btrfs_put_bbio()'s line for combine, and makes logic clean.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:43:40 -08:00
Qu Wenruo f04b772bfc btrfs: Enhance chunk validation check
Enhance chunk validation:
1) Num_stripes
   We already have such check but it's only in super block sys chunk
   array.
   Now check all on-disk chunks.

2) Chunk logical
   It should be aligned to sector size.
   This behavior should be *DOUBLE CHECKED* for 64K sector size like
   PPC64 or AArch64.
   Maybe we can found some hidden bugs.

3) Chunk length
   Same as chunk logical, should be aligned to sector size.

4) Stripe length
   It should be power of 2.

5) Chunk type
   Any bit out of TYPE_MAS | PROFILE_MASK is invalid.

With all these much restrict rules, several fuzzed image reported in
mail list should no longer cause kernel panic.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:21:41 -08:00
Qu Wenruo 319e4d0661 btrfs: Enhance super validation check
Enhance btrfs_check_super_valid() function by the following points:
1) Restrict sector/node size check
   Not the old max/min valid check, but also check if it's a power of 2.
   So some bogus number like 12K node size won't pass now.

2) Super flag check
   For now, there is still some inconsistency between kernel and
   btrfs-progs super flags.
   And considering btrfs-progs may add new flags for super block, this
   check will only output warning.

3) Better root alignment check
   Now root bytenr is checked against sector size.

4) Move some check into btrfs_check_super_valid().
   Like node size vs leaf size check, and PAGESIZE vs sectorsize check.
   And magic number check.

Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:21:41 -08:00
Filipe Manana c2d6cb1636 Btrfs: fix deadlock running delayed iputs at transaction commit time
While running a stress test I ran into a deadlock when running the delayed
iputs at transaction time, which produced the following report and trace:

[  886.399989] =============================================
[  886.400871] [ INFO: possible recursive locking detected ]
[  886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted
[  886.402384] ---------------------------------------------
[  886.403182] fio/8277 is trying to acquire lock:
[  886.403568]  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] but task is already holding lock:
[  886.403568]  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] other info that might help us debug this:
[  886.403568]  Possible unsafe locking scenario:
[  886.403568]
[  886.403568]        CPU0
[  886.403568]        ----
[  886.403568]   lock(&fs_info->delayed_iput_sem);
[  886.403568]   lock(&fs_info->delayed_iput_sem);
[  886.403568]
[  886.403568]  *** DEADLOCK ***
[  886.403568]
[  886.403568]  May be due to missing lock nesting notation
[  886.403568]
[  886.403568] 3 locks held by fio/8277:
[  886.403568]  #0:  (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0
[  886.403568]  #1:  (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs]
[  886.403568]  #2:  (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.403568]
[  886.403568] stack backtrace:
[  886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[  886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[  886.403568]  0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0
[  886.403568]  ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290
[  886.403568]  0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804
[  886.403568] Call Trace:
[  886.403568]  [<ffffffff8125d4fd>] dump_stack+0x4e/0x79
[  886.403568]  [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b
[  886.403568]  [<ffffffff810c22db>] ? __module_address+0xdf/0x108
[  886.403568]  [<ffffffff8108eb77>] lock_acquire+0x10d/0x194
[  886.403568]  [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194
[  886.403568]  [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffff8148556b>] down_read+0x3e/0x4d
[  886.489542]  [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs]
[  886.489542]  [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs]
[  886.489542]  [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs]
[  886.489542]  [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs]
[  886.489542]  [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs]
[  886.489542]  [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs]
[  886.489542]  [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs]
[  886.489542]  [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs]
[  886.489542]  [<ffffffff81188e31>] evict+0xa7/0x15c
[  886.489542]  [<ffffffff81189878>] iput+0x1d3/0x266
[  886.489542]  [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs]
[  886.489542]  [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs]
[  886.489542]  [<ffffffff81085096>] ? signal_pending_state+0x31/0x31
[  886.489542]  [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs]
[  886.489542]  [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs]
[  886.489542]  [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs]
[  886.489542]  [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs]
[  886.489542]  [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128
[  886.489542]  [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs]
[  886.489542]  [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50
[  886.489542]  [<ffffffff8117279e>] __vfs_write+0x7c/0xa5
[  886.489542]  [<ffffffff81172cda>] vfs_write+0xa0/0xe4
[  886.489542]  [<ffffffff811734cc>] SyS_write+0x50/0x7e
[  886.489542]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds.
[ 1081.854348]       Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1081.863227] fio        D ffff880213f9bb28     0  8244   8240 0x00000000
[ 1081.868719]  ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240
[ 1081.872499]  ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400
[ 1081.876834]  ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4
[ 1081.880782] Call Trace:
[ 1081.881793]  [<ffffffff81482ba4>] schedule+0x7f/0x97
[ 1081.883340]  [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325
[ 1081.895525]  [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab
[ 1081.897419]  [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20
[ 1081.899251]  [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20
[ 1081.901063]  [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21
[ 1081.902365]  [<ffffffff814855bd>] down_write+0x43/0x57
[ 1081.903846]  [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1081.906078]  [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1081.908846]  [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c
[ 1081.910409]  [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs]
[ 1081.912482]  [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs]
[ 1081.914597]  [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs]
[ 1081.919037]  [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128
[ 1081.920754]  [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs]
[ 1081.922496]  [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50
[ 1081.923922]  [<ffffffff8117279e>] __vfs_write+0x7c/0xa5
[ 1081.925275]  [<ffffffff81172cda>] vfs_write+0xa0/0xe4
[ 1081.926584]  [<ffffffff811734cc>] SyS_write+0x50/0x7e
[ 1081.927968]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f
[ 1081.985293] INFO: lockdep is turned off.
[ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds.
[ 1081.987434]       Not tainted 4.4.0-rc6-btrfs-next-18+ #1
[ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1081.990147] fio        D ffff880218febbb8     0  8249   8240 0x00000000
[ 1081.991626]  ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240
[ 1081.993258]  ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00
[ 1081.994850]  ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4
[ 1081.996485] Call Trace:
[ 1081.997037]  [<ffffffff81482ba4>] schedule+0x7f/0x97
[ 1081.998017]  [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325
[ 1081.999241]  [<ffffffff810852a5>] ? finish_wait+0x6d/0x76
[ 1082.000306]  [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20
[ 1082.001533]  [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20
[ 1082.002776]  [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21
[ 1082.003995]  [<ffffffff814855bd>] down_write+0x43/0x57
[ 1082.005000]  [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1082.007403]  [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs]
[ 1082.008988]  [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs]
[ 1082.010193]  [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77
[ 1082.011280]  [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0
[ 1082.012265]  [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0
[ 1082.013021]  [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff
[ 1082.013738]  [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b
[ 1082.014778]  [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea
[ 1082.015778]  [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e
[ 1082.016806]  [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71
[ 1082.017789]  [<ffffffff8118240e>] SyS_ioctl+0x57/0x79
[ 1082.018706]  [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f

This happens because we can recursively acquire the semaphore
fs_info->delayed_iput_sem when attempting to allocate space to satisfy
a file write request as shown in the first trace above - when committing
a transaction we acquire (down_read) the semaphore before running the
delayed iputs, and when running a delayed iput() we can end up calling
an inode's eviction handler, which in turn commits another transaction
and attempts to acquire (down_read) again the semaphore to run more
delayed iput operations.
This results in a deadlock because if a task acquires multiple times a
semaphore it should invoke down_read_nested() with a different lockdep
class for each level of recursion.

Fix this by simplifying the implementation and use a mutex instead that
is acquired by the cleaner kthread before it runs the delayed iputs
instead of always acquiring a semaphore before delayed references are
run from anywhere.

Fixes: d7c151717a (btrfs: Fix NO_SPACE bug caused by delayed-iput)
Cc: stable@vger.kernel.org   # 4.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:21:41 -08:00
Filipe Manana fedc00455c Btrfs: fix typo in log message when starting a balance
The recent change titled "Btrfs: Check metadata redundancy on balance"
(already in linux-next) left a typo in a message for users:
metatdata -> metadata.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19 18:21:40 -08:00
Chris Mason 326f784281 Merge branch 'misc-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 2016-01-19 18:21:30 -08:00
Chris Mason acc308556c Merge branch 'misc-cleanups-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 2016-01-19 18:21:00 -08:00
Colin Ian King fb75d857a3 btrfs: remove duplicate const specifier
duplicate const is redundant so remove it

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-19 10:33:56 +01:00
Linus Torvalds c1a198d923 Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "This has our usual assortment of fixes and cleanups, but the biggest
  change included is Omar Sandoval's free space tree.  It's not the
  default yet, mounting -o space_cache=v2 enables it and sets a readonly
  compat bit.  The tree can actually be deleted and regenerated if there
  are any problems, but it has held up really well in testing so far.

  For very large filesystems (30T+) our existing free space caching code
  can end up taking a huge amount of time during commits.  The new tree
  based code is faster and less work overall to update as the commit
  progresses.

  Omar worked on this during the summer and we'll hammer on it in
  production here at FB over the next few months"

* 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (73 commits)
  Btrfs: fix fitrim discarding device area reserved for boot loader's use
  Btrfs: Check metadata redundancy on balance
  btrfs: statfs: report zero available if metadata are exhausted
  btrfs: preallocate path for snapshot creation at ioctl time
  btrfs: allocate root item at snapshot ioctl time
  btrfs: do an allocation earlier during snapshot creation
  btrfs: use smaller type for btrfs_path locks
  btrfs: use smaller type for btrfs_path lowest_level
  btrfs: use smaller type for btrfs_path reada
  btrfs: cleanup, use enum values for btrfs_path reada
  btrfs: constify static arrays
  btrfs: constify remaining structs with function pointers
  btrfs tests: replace whole ops structure for free space tests
  btrfs: use list_for_each_entry* in backref.c
  btrfs: use list_for_each_entry_safe in free-space-cache.c
  btrfs: use list_for_each_entry* in check-integrity.c
  Btrfs: use linux/sizes.h to represent constants
  btrfs: cleanup, remove stray return statements
  btrfs: zero out delayed node upon allocation
  btrfs: pass proper enum type to start_transaction()
  ...
2016-01-18 12:44:40 -08:00
Sebastian Andrzej Siewior 546bed6312 btrfs: initialize the seq counter in struct btrfs_device
I managed to trigger this:
| INFO: trying to register non-static key.
| the code is fine but needs lockdep annotation.
| turning off the locking correctness validator.
| CPU: 1 PID: 781 Comm: systemd-gpt-aut Not tainted 4.4.0-rt2+ #14
| Hardware name: ARM-Versatile Express
| [<80307cec>] (dump_stack)
| [<80070e98>] (__lock_acquire)
| [<8007184c>] (lock_acquire)
| [<80287800>] (btrfs_ioctl)
| [<8012a8d4>] (do_vfs_ioctl)
| [<8012ac14>] (SyS_ioctl)

so I think that btrfs_device_data_ordered_init() is not invoked behind
a macro somewhere.

Fixes: 7cc8e58d53 ("Btrfs: fix unprotected device's variants on 32bits machine")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:28:43 +01:00
Dan Carpenter 0dc924c5f2 Btrfs: clean up an error code in btrfs_init_space_info()
If we return 1 here, then the caller treats it as an error and returns
-EINVAL.  It causes a static checker warning to treat positive returns
as an error.

Fixes: 1aba86d67f ('Btrfs: fix easily get into ENOSPC in mixed case')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:27:28 +01:00
Geliang Tang 8e217858ee btrfs: fix iterator with update error in backref.c
Fix the following error:

fs/btrfs/backref.c:565:1-20: iterator with update on line 577

Fixes: a7ca422('btrfs: use list_for_each_entry* in backref.c')
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:27:18 +01:00
Tsutomu Itoh b7c47bbb2d Btrfs: fix output of compression message in btrfs_parse_options()
The compression message might not be correctly output.
Fix it.

[[before fix]]

# mount -o compress /dev/sdb3 /test3
[  996.874264] BTRFS info (device sdb3): disk space caching is enabled
[  996.874268] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress-force /dev/sdb3 /test3
[ 1035.075017] BTRFS info (device sdb3): force zlib compression
[ 1035.075021] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress /dev/sdb3 /test3
[ 1053.679092] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

[[after fix]]

# mount -o compress /dev/sdb3 /test3
[  401.021753] BTRFS info (device sdb3): use zlib compression
[  401.021758] BTRFS info (device sdb3): disk space caching is enabled
[  401.021760] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress-force /dev/sdb3 /test3
[  439.824624] BTRFS info (device sdb3): force zlib compression
[  439.824629] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)

# mount -o remount,compress /dev/sdb3 /test3
[  459.918430] BTRFS info (device sdb3): use zlib compression
[  459.918434] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:25:36 +01:00
Chandan Rajendra f32e48e925 Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots
The following call trace is seen when btrfs/031 test is executed in a loop,

[  158.661848] ------------[ cut here ]------------
[  158.662634] WARNING: CPU: 2 PID: 890 at /home/chandan/repos/linux/fs/btrfs/ioctl.c:558 create_subvol+0x3d1/0x6ea()
[  158.664102] BTRFS: Transaction aborted (error -2)
[  158.664774] Modules linked in:
[  158.665266] CPU: 2 PID: 890 Comm: btrfs Not tainted 4.4.0-rc6-g511711a #2
[  158.666251] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[  158.667392]  ffffffff81c0a6b0 ffff8806c7c4f8e8 ffffffff81431fc8 ffff8806c7c4f930
[  158.668515]  ffff8806c7c4f920 ffffffff81051aa1 ffff880c85aff000 ffff8800bb44d000
[  158.669647]  ffff8808863b5c98 0000000000000000 00000000fffffffe ffff8806c7c4f980
[  158.670769] Call Trace:
[  158.671153]  [<ffffffff81431fc8>] dump_stack+0x44/0x5c
[  158.671884]  [<ffffffff81051aa1>] warn_slowpath_common+0x81/0xc0
[  158.672769]  [<ffffffff81051b27>] warn_slowpath_fmt+0x47/0x50
[  158.673620]  [<ffffffff813bc98d>] create_subvol+0x3d1/0x6ea
[  158.674440]  [<ffffffff813777c9>] btrfs_mksubvol.isra.30+0x369/0x520
[  158.675376]  [<ffffffff8108a4aa>] ? percpu_down_read+0x1a/0x50
[  158.676235]  [<ffffffff81377a81>] btrfs_ioctl_snap_create_transid+0x101/0x180
[  158.677268]  [<ffffffff81377b52>] btrfs_ioctl_snap_create+0x52/0x70
[  158.678183]  [<ffffffff8137afb4>] btrfs_ioctl+0x474/0x2f90
[  158.678975]  [<ffffffff81144b8e>] ? vma_merge+0xee/0x300
[  158.679751]  [<ffffffff8115be31>] ? alloc_pages_vma+0x91/0x170
[  158.680599]  [<ffffffff81123f62>] ? lru_cache_add_active_or_unevictable+0x22/0x70
[  158.681686]  [<ffffffff813d99cf>] ? selinux_file_ioctl+0xff/0x1d0
[  158.682581]  [<ffffffff8117b791>] do_vfs_ioctl+0x2c1/0x490
[  158.683399]  [<ffffffff813d3cde>] ? security_file_ioctl+0x3e/0x60
[  158.684297]  [<ffffffff8117b9d4>] SyS_ioctl+0x74/0x80
[  158.685051]  [<ffffffff819b2bd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
[  158.685958] ---[ end trace 4b63312de5a2cb76 ]---
[  158.686647] BTRFS: error (device loop0) in create_subvol:558: errno=-2 No such entry
[  158.709508] BTRFS info (device loop0): forced readonly
[  158.737113] BTRFS info (device loop0): disk space caching is enabled
[  158.738096] BTRFS error (device loop0): Remounting read-write after error is not allowed
[  158.851303] BTRFS error (device loop0): cleaner transaction attach returned -30

This occurs because,

Mount filesystem
Create subvol with ID 257
Unmount filesystem
Mount filesystem
Delete subvol with ID 257
  btrfs_drop_snapshot()
    Add root corresponding to subvol 257 into
    btrfs_transaction->dropped_roots list
Create new subvol (i.e. create_subvol())
  257 is returned as the next free objectid
  btrfs_read_fs_root_no_name()
    Finds the btrfs_root instance corresponding to the old subvol with ID 257
    in btrfs_fs_info->fs_roots_radix.
    Returns error since btrfs_root_item->refs has the value of 0.

To fix the issue the commit initializes tree root's and subvolume root's
highest_objectid when loading the roots from disk.

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:25:02 +01:00
Jeff Mahoney 95617d6932 btrfs: cleanup, stop casting for extent_map->lookup everywhere
Overloading extent_map->bdev to struct map_lookup * might have started out
as a means to an end, but it's a pattern that's used all over the place
now. Let's get rid of the casting and just add a union instead.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-15 19:22:28 +01:00
Vladimir Davydov 5d097056c9 kmemcg: account certain kmem allocations to memcg
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Linus Torvalds 33caf82acf Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...
2016-01-12 17:11:47 -08:00
Linus Torvalds fce205e9da Merge branch 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs copy_file_range updates from Al Viro:
 "Several series around copy_file_range/CLONE"

* 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  btrfs: use new dedupe data function pointer
  vfs: hoist the btrfs deduplication ioctl to the vfs
  vfs: wire up compat ioctl for CLONE/CLONE_RANGE
  cifs: avoid unused variable and label
  nfsd: implement the NFSv4.2 CLONE operation
  nfsd: Pass filehandle to nfs4_preprocess_stateid_op()
  vfs: pull btrfs clone API to vfs layer
  locks: new locks_mandatory_area calling convention
  vfs: Add vfs_copy_file_range() support for pagecache copies
  btrfs: add .copy_file_range file operation
  x86: add sys_copy_file_range to syscall tables
  vfs: add copy_file_range syscall and vfs helper
2016-01-12 16:30:34 -08:00
Linus Torvalds 67c707e451 Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
 "The main changes in this cycle were:

   - code patching and cpu_has cleanups (Borislav Petkov)

   - paravirt cleanups (Juergen Gross)

   - TSC cleanup (Thomas Gleixner)

   - ptrace cleanup (Chen Gang)"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch/x86/kernel/ptrace.c: Remove unused arg_offs_table
  x86/mm: Align macro defines
  x86/cpu: Provide a config option to disable static_cpu_has
  x86/cpufeature: Remove unused and seldomly used cpu_has_xx macros
  x86/cpufeature: Cleanup get_cpu_cap()
  x86/cpufeature: Move some of the scattered feature bits to x86_capability
  x86/paravirt: Remove paravirt ops pmd_update[_defer] and pte_update_defer
  x86/paravirt: Remove unused pv_apic_ops structure
  x86/tsc: Remove unused tsc_pre_init() hook
  x86: Remove unused function cpu_has_ht_siblings()
  x86/paravirt: Kill some unused patching functions
2016-01-11 16:26:03 -08:00
Linus Torvalds ddf1d6238d Merge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs xattr updates from Al Viro:
 "Andreas' xattr cleanup series.

  It's a followup to his xattr work that went in last cycle; -0.5KLoC"

* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  xattr handlers: Simplify list operation
  ocfs2: Replace list xattr handler operations
  nfs: Move call to security_inode_listsecurity into nfs_listxattr
  xfs: Change how listxattr generates synthetic attributes
  tmpfs: listxattr should include POSIX ACL xattrs
  tmpfs: Use xattr handler infrastructure
  btrfs: Use xattr handler infrastructure
  vfs: Distinguish between full xattr names and proper prefixes
  posix acls: Remove duplicate xattr name definitions
  gfs2: Remove gfs2_xattr_acl_chmod
  vfs: Remove vfs_xattr_cmp
2016-01-11 13:32:10 -08:00
Linus Torvalds 32fb378437 Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs RCU symlink updates from Al Viro:
 "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode
  even if the symlink is not an embedded one.

  No changes since the mailbomb on Jan 1"

* 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->get_link() to delayed_call, kill ->put_link()
  kill free_page_put_link()
  teach nfs_get_link() to work in RCU mode
  teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode
  teach shmem_get_link() to work in RCU mode
  teach page_get_link() to work in RCU mode
  replace ->follow_link() with new method that could stay in RCU mode
  don't put symlink bodies in pagecache into highmem
  namei: page_getlink() and page_follow_link_light() are the same thing
  ufs: get rid of ->setattr() for symlinks
  udf: don't duplicate page_symlink_inode_operations
  logfs: don't duplicate page_symlink_inode_operations
  switch befs long symlinks to page_symlink_operations
2016-01-11 13:13:23 -08:00
Chris Mason 988f1f576d Merge branch 'for-chris-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.5
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-11 08:39:28 -08:00
Chris Mason b28cf57246 Merge branch 'misc-cleanups-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
Signed-off-by: Chris Mason <clm@fb.com>
2016-01-11 06:08:37 -08:00
Chris Mason a3058101c1 Merge branch 'misc-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 2016-01-11 05:59:32 -08:00
Filipe Manana 8cdc7c5b00 Btrfs: fix fitrim discarding device area reserved for boot loader's use
As of the 4.3 kernel release, the fitrim ioctl can now discard any region
of a disk that is not allocated to any chunk/block group, including the
first megabyte which is used for our primary superblock and by the boot
loader (grub for example).

Fix this by not allowing to trim/discard any region in the device starting
with an offset not greater than min(alloc_start_mount_option, 1Mb), just
as it was not possible before 4.3.

A reproducer test case for xfstests follows.

  seq=`basename $0`
  seqres=$RESULT_DIR/$seq
  echo "QA output created by $seq"
  tmp=/tmp/$$
  status=1	# failure is the default!
  trap "_cleanup; exit \$status" 0 1 2 3 15

  _cleanup()
  {
      cd /
      rm -f $tmp.*
  }

  # get standard environment, filters and checks
  . ./common/rc
  . ./common/filter

  # real QA test starts here
  _need_to_be_root
  _supported_fs btrfs
  _supported_os Linux
  _require_scratch

  rm -f $seqres.full

  _scratch_mkfs >>$seqres.full 2>&1

  # Write to the [0, 64Kb[ and [68Kb, 1Mb[ ranges of the device. These ranges are
  # reserved for a boot loader to use (GRUB for example) and btrfs should never
  # use them - neither for allocating metadata/data nor should trim/discard them.
  # The range [64Kb, 68Kb[ is used for the primary superblock of the filesystem.
  $XFS_IO_PROG -c "pwrite -S 0xfd 0 64K" $SCRATCH_DEV | _filter_xfs_io
  $XFS_IO_PROG -c "pwrite -S 0xfd 68K 956K" $SCRATCH_DEV | _filter_xfs_io

  # Now mount the filesystem and perform a fitrim against it.
  _scratch_mount
  _require_batched_discard $SCRATCH_MNT
  $FSTRIM_PROG $SCRATCH_MNT

  # Now unmount the filesystem and verify the content of the ranges was not
  # modified (no trim/discard happened on them).
  _scratch_unmount
  echo "Content of the ranges [0, 64Kb] and [68Kb, 1Mb[ after fitrim:"
  od -t x1 -N $((64 * 1024)) $SCRATCH_DEV
  od -t x1 -j $((68 * 1024)) -N $((956 * 1024)) $SCRATCH_DEV

  status=0
  exit

Reported-by: Vincent Petry  <PVince81@yahoo.fr>
Reported-by: Andrei Borzenkov <arvidjaar@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109341
Fixes: 499f377f49 (btrfs: iterate over unused chunk space in FITRIM)
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-01-07 21:16:03 +00:00
Sam Tygier ee592d0771 Btrfs: Check metadata redundancy on balance
When converting a filesystem via balance check that metadata mode
is at least as redundant as the data mode. For example give warning
when:
-dconvert=raid1 -mconvert=single

Signed-off-by: Sam Tygier <samtygier@yahoo.co.uk>
[ minor message reformatting ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:20:56 +01:00
David Sterba ca8a51b3a9 btrfs: statfs: report zero available if metadata are exhausted
There is one ENOSPC case that's very confusing. There's Available
greater than zero but no file operation succeds (besides removing
files). This happens when the metadata are exhausted and there's no
possibility to allocate another chunk.

In this scenario it's normal that there's still some space in the data
chunk and the calculation in df reflects that in the Avail value.

To at least give some clue about the ENOSPC situation, let statfs report
zero value in Avail, even if there's still data space available.

Current:
  /dev/sdb1             4.0G  3.3G  719M  83% /mnt/test

New:
  /dev/sdb1             4.0G  3.3G     0 100% /mnt/test

We calculate the remaining metadata space minus global reserve. If this
is (supposedly) smaller than zero, there's no space. But this does not
hold in practice, the exhausted state happens where's still some
positive delta. So we apply some guesswork and compare the delta to a 4M
threshold. (Practically observed delta was 2M.)

We probably cannot calculate the exact threshold value because this
depends on the internal reservations requested by various operations, so
some operations that consume a few metadata will succeed even if the
Avail is zero. But this is better than the other way around.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:20:55 +01:00
David Sterba 8546b57051 btrfs: preallocate path for snapshot creation at ioctl time
We can also preallocate btrfs_path that's used during pending snapshot
creation and avoid another late ENOMEM failure.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:20:55 +01:00
David Sterba b0c0ea6338 btrfs: allocate root item at snapshot ioctl time
The actual snapshot creation is delayed until transaction commit. If we
cannot get enough memory for the root item there, we have to fail the
whole transaction commit which is bad. So we'll allocate the memory at
the ioctl call and pass it along with the pending_snapshot struct. The
potential ENOMEM will be returned to the caller of snapshot ioctl.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:20:54 +01:00
David Sterba a1ee736268 btrfs: do an allocation earlier during snapshot creation
We can allocate pending_snapshot earlier and do not have to do cleanup
in case of failure.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:20:54 +01:00
David Sterba 4fb72bf2e9 btrfs: use smaller type for btrfs_path locks
The values of btrfs_path::locks are 0 to 4, fit into a u8. Let's see:

* overall size of btrfs_path drops down from 136 to 112 (-24 bytes),
* better packing in a slab page +6 objects
* the whole structure now fits to 2 cachelines
* slight decrease in code size:

   text    data     bss     dec     hex filename
 938731   43670   23144 1005545   f57e9 fs/btrfs/btrfs.ko.before
 938203   43670   23144 1005017   f55d9 fs/btrfs/btrfs.ko.after

(and the generated assembly does not change much)

The main purpose is to decrease the size of the structure without
affecting performance. The byte access is usually well behaving accross
arches, the locks are not accessed frequently and sometimes just
compared to zero.

Note for further size reduction attempts: the slots could be made u16
but this might generate worse code on some arches (non-byte and non-int
access). Also the range of operations on slots is wider compared to
locks and the potential performance drop should be evaluated first.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:17 +01:00
David Sterba 7853f15b2a btrfs: use smaller type for btrfs_path lowest_level
The level is 0..7, we can use smaller type. The size of btrfs_path is now
136 bytes from 144, which is +2 objects that fit into a 4k slab.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:17 +01:00
David Sterba dccabfad20 btrfs: use smaller type for btrfs_path reada
The possible values for reada are all positive and bounded, we can later
save some bytes by storing it in u8.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:16 +01:00
David Sterba e4058b54d1 btrfs: cleanup, use enum values for btrfs_path reada
Replace the integers by enums for better readability. The value 2 does
not have any meaning since a717531942
"Btrfs: do less aggressive btree readahead" (2009-01-22).

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:15 +01:00
David Sterba 4d4ab6d6bc btrfs: constify static arrays
There are a few statically initialized arrays that can be made const.
The remaining (like file_system_type, sysfs attributes or prop handlers)
do not allow that due to type mismatch when passed to the APIs or
because the structures are modified through other members.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:15 +01:00
David Sterba 20e5506baf btrfs: constify remaining structs with function pointers
* struct extent_io_ops
* struct btrfs_free_space_op

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:14 +01:00
David Sterba 28f0779a3f btrfs tests: replace whole ops structure for free space tests
Preparatory work for making btrfs_free_space_op constant. In
test_steal_space_from_bitmap_to_extent, we substitute use_bitmap with
own version thus preventing constification. We can rework it so we
replace the whole structure with the correct function pointers.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 15:01:14 +01:00
Geliang Tang a7ca42256d btrfs: use list_for_each_entry* in backref.c
Use list_for_each_entry*() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 14:42:46 +01:00
Geliang Tang 7ae1681e12 btrfs: use list_for_each_entry_safe in free-space-cache.c
Use list_for_each_entry_safe() instead of list_for_each_safe() to
simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-07 14:39:09 +01:00