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* btrfs: use rbio->nr_pages to reduce calculationZhao Lei2016-01-201-12/+7
| | | | | | | | 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>
* btrfs: Use unified stripe_page's index calculationZhao Lei2016-01-201-22/+21
| | | | | | | | | | | | | | | | 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>
* btrfs: Fix calculation of rbio->dbitmap's size calculationZhao Lei2016-01-202-3/+3
| | | | | | | | | | | 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>
* btrfs: Fix no_space in write and rm loopZhao Lei2016-01-201-1/+3
| | | | | | | | | | | | | | | | | | | | | 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 bdced438acd8 ("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>
* btrfs: merge functions for wait snapshot creationZhao Lei2016-01-203-21/+22
| | | | | | | | | | | | 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>
* btrfs: delete unused argument in btrfs_copy_from_userZhao Lei2016-01-201-4/+2
| | | | | | | | 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>
* btrfs: Use direct way to determine raid56 write/recover modeZhao Lei2016-01-191-1/+2
| | | | | | | | | | | 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>
* btrfs: Small cleanup for get index_srcdev loopZhao Lei2016-01-191-22/+20
| | | | | | | | 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>
* btrfs: Enhance chunk validation checkQu Wenruo2016-01-191-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* btrfs: Enhance super validation checkQu Wenruo2016-01-191-49/+48
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Btrfs: fix deadlock running delayed iputs at transaction commit timeFilipe Manana2016-01-194-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: d7c151717a1e (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>
* Btrfs: fix typo in log message when starting a balanceFilipe Manana2016-01-191-1/+1
| | | | | | | | | 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>
* Merge branch 'misc-for-4.5' of ↵Chris Mason2016-01-196-15/+56
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
| * btrfs: initialize the seq counter in struct btrfs_deviceSebastian Andrzej Siewior2016-01-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 7cc8e58d53cd ("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>
| * Btrfs: fix output of compression message in btrfs_parse_options()Tsutomu Itoh2016-01-151-7/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and ↵Chandan Rajendra2016-01-154-8/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'misc-cleanups-4.5' of ↵Chris Mason2016-01-197-24/+32
|\ \ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
| * | btrfs: remove duplicate const specifierColin Ian King2016-01-191-1/+1
| | | | | | | | | | | | | | | | | | | | | 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>
| * | Btrfs: clean up an error code in btrfs_init_space_info()Dan Carpenter2016-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 1aba86d67f34 ('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>
| * | btrfs: fix iterator with update error in backref.cGeliang Tang2016-01-151-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: cleanup, stop casting for extent_map->lookup everywhereJeff Mahoney2016-01-156-17/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | Merge branch 'for-chris-4.5' of ↵Chris Mason2016-01-114-18/+58
|\ \ \ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.5 Signed-off-by: Chris Mason <clm@fb.com>
| * | | Btrfs: fix fitrim discarding device area reserved for boot loader's useFilipe Manana2016-01-071-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 499f377f49f0 (btrfs: iterate over unused chunk space in FITRIM) Cc: stable@vger.kernel.org # 4.3+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | Btrfs: fix transaction handle leak on failure to create hard linkFilipe Manana2016-01-061-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we failed to create a hard link we were not always releasing the the transaction handle we got before, resulting in a memory leak and preventing any other tasks from being able to commit the current transaction. Fix this by always releasing our transaction handle. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
| * | | Btrfs: fix number of transaction units required to create symlinkFilipe Manana2015-12-311-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We weren't accounting for the insertion of an inline extent item for the symlink inode nor that we need to update the parent inode item (through the call to btrfs_add_nondir()). So fix this by including two more transaction units. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | Btrfs: don't leave dangling dentry if symlink creation failedFilipe Manana2015-12-311-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we are creating a symlink we might fail with an error after we created its inode and added the corresponding directory indexes to its parent inode. In this case we end up never removing the directory indexes because the inode eviction handler, called for our symlink inode on the final iput(), only removes items associated with the symlink inode and not with the parent inode. Example: $ mkfs.btrfs -f /dev/sdi $ mount /dev/sdi /mnt $ touch /mnt/foo $ ln -s /mnt/foo /mnt/bar ln: failed to create symbolic link ‘bar’: Cannot allocate memory $ umount /mnt $ btrfsck /dev/sdi Checking filesystem on /dev/sdi UUID: d5acb5ba-31bd-42da-b456-89dca2e716e1 checking extents checking free space cache checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 256 index 3 namelen 3 name bar filetype 7 errors 4, no inode ref found 131073 bytes used err is 1 total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 124305 file data blocks allocated: 262144 referenced 262144 btrfs-progs v4.2.3 So fix this by adding the directory index entries as the very last step of symlink creation. Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | Btrfs: send, don't BUG_ON() when an empty symlink is foundFilipe Manana2015-12-311-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a symlink is successfully created it always has an inline extent containing the source path. However if an error happens when creating the symlink, we can leave in the subvolume's tree a symlink inode without any such inline extent item - this happens if after btrfs_symlink() calls btrfs_end_transaction() and before it calls the inode eviction handler (through the final iput() call), the transaction gets committed and a crash happens before the eviction handler gets called, or if a snapshot of the subvolume is made before the eviction handler gets called. Sadly we can't just avoid this by making btrfs_symlink() call btrfs_end_transaction() after it calls the eviction handler, because the later can commit the current transaction before it removes any items from the subvolume tree (if it encounters ENOSPC errors while reserving space for removing all the items). So make send fail more gracefully, with an -EIO error, and print a message to dmesg/syslog informing that there's an empty symlink inode, so that the user can delete the empty symlink or do something else about it. Reported-by: Stephen R. van den Berg <srb@cuci.nl> Signed-off-by: Filipe Manana <fdmanana@suse.com>
| * | | Btrfs: fix race between free space endio workers and space cache writeoutFilipe Manana2015-12-301-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running a stress test I ran into the following trace/transaction abort: [471626.672243] ------------[ cut here ]------------ [471626.673322] WARNING: CPU: 9 PID: 19107 at fs/btrfs/extent-tree.c:3740 btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs]() [471626.675492] BTRFS: Transaction aborted (error -2) [471626.676748] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop fuse parport_pc i2c_piix [471626.688802] CPU: 14 PID: 19107 Comm: fsstress Tainted: G W 4.3.0-rc5-btrfs-next-17+ #1 [471626.690148] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014 [471626.691901] 0000000000000000 ffff880016037cf0 ffffffff812566f4 ffff880016037d38 [471626.695009] ffff880016037d28 ffffffff8104d0a6 ffffffffa040c84e 00000000fffffffe [471626.697490] ffff88011fe855f8 ffff88000c484cb0 ffff88000d195000 ffff880016037d90 [471626.699201] Call Trace: [471626.699804] [<ffffffff812566f4>] dump_stack+0x4e/0x79 [471626.701049] [<ffffffff8104d0a6>] warn_slowpath_common+0x9f/0xb8 [471626.702542] [<ffffffffa040c84e>] ? btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [471626.704326] [<ffffffff8104d107>] warn_slowpath_fmt+0x48/0x50 [471626.705636] [<ffffffffa0403717>] ? write_one_cache_group.isra.32+0x77/0x82 [btrfs] [471626.707048] [<ffffffffa040c84e>] btrfs_write_dirty_block_groups+0x17c/0x214 [btrfs] [471626.708616] [<ffffffffa048a50a>] commit_cowonly_roots+0x1d7/0x25a [btrfs] [471626.709950] [<ffffffffa041e34a>] btrfs_commit_transaction+0x4c4/0x991 [btrfs] [471626.711286] [<ffffffff81081c61>] ? signal_pending_state+0x31/0x31 [471626.712611] [<ffffffffa03f6df4>] btrfs_sync_fs+0x145/0x1ad [btrfs] [471626.715610] [<ffffffff811962a2>] ? SyS_tee+0x226/0x226 [471626.716718] [<ffffffff811962c2>] sync_fs_one_sb+0x20/0x22 [471626.717672] [<ffffffff8116fc01>] iterate_supers+0x75/0xc2 [471626.718800] [<ffffffff8119669a>] sys_sync+0x52/0x80 [471626.719990] [<ffffffff8147cd97>] entry_SYSCALL_64_fastpath+0x12/0x6f [471626.721835] ---[ end trace baf57f43d76693f4 ]--- [471626.722954] BTRFS: error (device sdc) in btrfs_write_dirty_block_groups:3740: errno=-2 No such entry This is a very rare situation and it happened due to a race between a free space endio worker and writing the space caches for dirty block groups at a transaction's commit critical section. The steps leading to this are: 1) A task calls btrfs_commit_transaction() and starts the writeout of the space caches for all currently dirty block groups (i.e. it calls btrfs_start_dirty_block_groups()); 2) The previous step starts writeback for space caches; 3) When the writeback finishes it queues jobs for free space endio work queue (fs_info->endio_freespace_worker) that execute btrfs_finish_ordered_io(); 4) The task committing the transaction sets the transaction's state to TRANS_STATE_COMMIT_DOING and shortly after calls btrfs_write_dirty_block_groups(); 5) A free space endio job joins the transaction, through btrfs_join_transaction_nolock(), and updates a free space inode item in the root tree through btrfs_update_inode_fallback(); 6) Updating the free space inode item resulted in COWing one or more nodes/leaves of the root tree, and that resulted in creating a new metadata block group, which gets added to the transaction's list of dirty block groups (this is a very rare case); 7) The free space endio job has not released yet its transaction handle at this point, so the new metadata block group was not yet fully created (didn't go through btrfs_create_pending_block_groups() yet); 8) The transaction commit task sees the new metadata block group in the transaction's list of dirty block groups and processes it. When it attempts to update the block group's block group item in the extent tree, through write_one_cache_group(), it isn't able to find it and aborts the transaction with error -ENOENT - this is because the free space endio job hasn't yet released its transaction handle (which calls btrfs_create_pending_block_groups()) and therefore the block group item was not yet added to the extent tree. Fix this waiting for free space endio jobs if we fail to find a block group item in the extent tree and then retry once updating the block group item. Signed-off-by: Filipe Manana <fdmanana@suse.com>
* | | | Merge branch 'misc-cleanups-4.5' of ↵Chris Mason2016-01-1124-305/+195
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 Signed-off-by: Chris Mason <clm@fb.com>
| * | | btrfs: use list_for_each_entry* in backref.cGeliang Tang2016-01-071-17/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | btrfs: use list_for_each_entry_safe in free-space-cache.cGeliang Tang2016-01-071-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | btrfs: use list_for_each_entry* in check-integrity.cGeliang Tang2016-01-071-79/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use list_for_each_entry*() instead of list_for_each*() 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>
| * | | Btrfs: use linux/sizes.h to represent constantsByongho Lee2016-01-0717-177/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use many constants to represent size and offset value. And to make code readable we use '256 * 1024 * 1024' instead of '268435456' to represent '256MB'. However we can make far more readable with 'SZ_256MB' which is defined in the 'linux/sizes.h'. So this patch replaces 'xxx * 1024 * 1024' kind of expression with single 'SZ_xxxMB' if 'xxx' is a power of 2 then 'xxx * SZ_1M' if 'xxx' is not a power of 2. And I haven't touched to '4096' & '8192' because it's more intuitive than 'SZ_4KB' & 'SZ_8KB'. Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | btrfs: cleanup, remove stray return statementsDavid Sterba2016-01-076-9/+0
| | | | | | | | | | | | | | | | Signed-off-by: David Sterba <dsterba@suse.com>
| * | | btrfs: zero out delayed node upon allocationAlexandru Moise2016-01-071-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's slightly cleaner to zero-out the delayed node upon allocation than to do it by hand in btrfs_init_delayed_node() for a few members Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | btrfs: pass proper enum type to start_transaction()Alexandru Moise2016-01-071-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | btrfs: switch __btrfs_fs_incompat return type from int to boolAlexandru Moise2016-01-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conform to __btrfs_fs_incompat() cast-to-bool (!!) by explicitly returning boolean not int. Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | btrfs: remove unused inode argument from uncompress_inline()Byongho Lee2016-01-071-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The inode argument is never used from the beginning, so remove it. Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | | | Merge branch 'misc-for-4.5' of ↵Chris Mason2016-01-1122-144/+186
|\ \ \ \ | |_|/ / |/| | / | | |/ | |/| git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
| * | Btrfs: Check metadata redundancy on balanceSam Tygier2016-01-071-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: statfs: report zero available if metadata are exhaustedDavid Sterba2016-01-071-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: preallocate path for snapshot creation at ioctl timeDavid Sterba2016-01-073-6/+8
| | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: allocate root item at snapshot ioctl timeDavid Sterba2016-01-073-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: do an allocation earlier during snapshot creationDavid Sterba2016-01-071-11/+9
| | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: use smaller type for btrfs_path locksDavid Sterba2016-01-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: use smaller type for btrfs_path lowest_levelDavid Sterba2016-01-071-1/+1
| | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: use smaller type for btrfs_path readaDavid Sterba2016-01-071-1/+1
| | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: cleanup, use enum values for btrfs_path readaDavid Sterba2016-01-0711-30/+30
| | | | | | | | | | | | | | | | | | | | | | | | Replace the integers by enums for better readability. The value 2 does not have any meaning since a717531942f488209dded30f6bc648167bcefa72 "Btrfs: do less aggressive btree readahead" (2009-01-22). Signed-off-by: David Sterba <dsterba@suse.com>
| * | btrfs: constify static arraysDavid Sterba2016-01-074-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | btrfs: constify remaining structs with function pointersDavid Sterba2016-01-075-8/+8
| | | | | | | | | | | | | | | | | | | | | * struct extent_io_ops * struct btrfs_free_space_op Signed-off-by: David Sterba <dsterba@suse.com>
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