summaryrefslogtreecommitdiff
path: root/fs/btrfs/volumes.c
AgeCommit message (Collapse)Author
2021-10-26btrfs: rename struct btrfs_io_bio to btrfs_bioQu Wenruo
Previously we had "struct btrfs_bio", which records IO context for mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra btrfs specific info for logical bytenr bio. With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename "btrfs_io_bio" to "btrfs_bio" which is a more suitable name now. The struct btrfs_bio changes meaning by this commit. There was a suggested name like btrfs_logical_bio but it's a bit long and we'd prefer to use a shorter name. This could be a concern for backports to older kernels where the different meaning could possibly cause confusion or bugs. Comparing the new and old structures, there's no overlap among the struct members so a build would break in case of incorrect backport. We haven't had many backports to bio code anyway so this is more of a theoretical cause of bugs and a matter of precaution but we'll need to keep the semantic change in mind. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: rename btrfs_bio to btrfs_io_contextQu Wenruo
The structure btrfs_bio is used by two different sites: - bio->bi_private for mirror based profiles For those profiles (SINGLE/DUP/RAID1*/RAID10), this structures records how many mirrors are still pending, and save the original endio function of the bio. - RAID56 code In that case, RAID56 only utilize the stripes info, and no long uses that to trace the pending mirrors. So btrfs_bio is not always bind to a bio, and contains more info for IO context, thus renaming it will make the naming less confusing. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: remove stale comment about the btrfs_show_devnameAnand Jain
There were few lockdep warnings because btrfs_show_devname() was using device_list_mutex as recorded in the commits: 0ccd05285e7f ("btrfs: fix a possible umount deadlock") 779bf3fefa83 ("btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex") And finally, commit 88c14590cdd6 ("btrfs: use RCU in btrfs_show_devname for device list traversal") removed the device_list_mutex from btrfs_show_devname for performance reasons. This patch removes a stale comment about the function btrfs_show_devname and device_list_mutex. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: update latest_dev when we create a sprout deviceAnand Jain
When we add a device to the seed filesystem (sprouting) it is a new filesystem (and fsid) on the device added. Update the latest_dev so that /proc/self/mounts shows the correct device. Example: $ btrfstune -S1 /dev/vg/seed $ mount /dev/vg/seed /btrfs mount: /btrfs: WARNING: device write-protected, mounted read-only. $ cat /proc/self/mounts | grep btrfs /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0 $ btrfs dev add -f /dev/vg/new /btrfs Before: $ cat /proc/self/mounts | grep btrfs /dev/mapper/vg-seed /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0 After: $ cat /proc/self/mounts | grep btrfs /dev/mapper/vg-new /btrfs btrfs ro,relatime,space_cache,subvolid=5,subvol=/ 0 0 Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: convert latest_bdev type to btrfs_device and renameAnand Jain
In preparation to fix a bug in btrfs_show_devname(). Convert fs_devices::latest_bdev type from struct block_device to struct btrfs_device and, rename the member to fs_devices::latest_dev. So that btrfs_show_devname() can use fs_devices::latest_dev::name. Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: rename and switch to bool btrfs_chunk_readonlyAnand Jain
btrfs_chunk_readonly() checks if the given chunk is writeable. It returns 1 for readonly, and 0 for writeable. So the return argument type bool shall suffice instead of the current type int. Also, rename btrfs_chunk_readonly() to btrfs_chunk_writeable() as we check if the bg is writeable, and helps to keep the logic at the parent function simpler to understand. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-25btrfs: update comment for fs_devices::seed_list in btrfs_rm_deviceSu Yue
Update it since commit 944d3f9fac61 ("btrfs: switch seed device to list api") did conversion from fs_devices::seed to fs_devices::seed_list. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Su Yue <l@damenly.su> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-25btrfs: rename btrfs_alloc_chunk to btrfs_create_chunkNikolay Borisov
The user facing function used to allocate new chunks is btrfs_chunk_alloc, unfortunately there is yet another similar sounding function - btrfs_alloc_chunk. This creates confusion, especially since the latter function can be considered "private" in the sense that it implements the first stage of chunk creation and as such is called by btrfs_chunk_alloc. To avoid the awkwardness that comes with having similarly named but distinctly different in their purpose function rename btrfs_alloc_chunk to btrfs_create_chunk, given that the main purpose of this function is to orchestrate the whole process of allocating a chunk - reserving space into devices, deciding on characteristics of the stripe size and creating the in-memory structures. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-22btrfs: use sync_blockdevChristoph Hellwig
Use sync_blockdev instead of opencoding it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Acked-by: David Sterba <dsterba@suse.com> Link: https://lore.kernel.org/r/20211019062530.2174626-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18btrfs: use bdev_nr_bytes instead of open coding itChristoph Hellwig
Use the proper helper to read the block device size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Acked-by: David Sterba <dsterba@suse.com> Link: https://lore.kernel.org/r/20211018101130.1838532-13-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-17btrfs: fix mount failure due to past and transient device flush errorFilipe Manana
When we get an error flushing one device, during a super block commit, we record the error in the device structure, in the field 'last_flush_error'. This is used to later check if we should error out the super block commit, depending on whether the number of flush errors is greater than or equals to the maximum tolerated device failures for a raid profile. However if we get a transient device flush error, unmount the filesystem and later try to mount it, we can fail the mount because we treat that past error as critical and consider the device is missing. Even if it's very likely that the error will happen again, as it's probably due to a hardware related problem, there may be cases where the error might not happen again. One example is during testing, and a test case like the new generic/648 from fstests always triggers this. The test cases generic/019 and generic/475 also trigger this scenario, but very sporadically. When this happens we get an error like this: $ mount /dev/sdc /mnt mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error. $ dmesg (...) [12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount [12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices [12918.890853] BTRFS error (device sdc): open_ctree failed The failure happens because when btrfs_check_rw_degradable() is called at mount time, or at remount from RO to RW time, is sees a non zero value in a device's ->last_flush_error attribute, and therefore considers that the device is 'missing'. Fix this by setting a device's ->last_flush_error to zero when we close a device, making sure the error is not seen on the next mount attempt. We only need to track flush errors during the current mount, so that we never commit a super block if such errors happened. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: fix lockdep warning while mounting sprout fsAnand Jain
Following test case reproduces lockdep warning. Test case: $ mkfs.btrfs -f <dev1> $ btrfstune -S 1 <dev1> $ mount <dev1> <mnt> $ btrfs device add <dev2> <mnt> -f $ umount <mnt> $ mount <dev2> <mnt> $ umount <mnt> The warning claims a possible ABBA deadlock between the threads initiated by [#1] btrfs device add and [#0] the mount. [ 540.743122] WARNING: possible circular locking dependency detected [ 540.743129] 5.11.0-rc7+ #5 Not tainted [ 540.743135] ------------------------------------------------------ [ 540.743142] mount/2515 is trying to acquire lock: [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs] [ 540.743458] but task is already holding lock: [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743541] which lock already depends on the new lock. [ 540.743543] the existing dependency chain (in reverse order) is: [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}: [ 540.743566] down_read_nested+0x48/0x2b0 [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs] [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs] [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs] [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs] [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs] [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs] [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs] [ 540.744166] __x64_sys_ioctl+0xe4/0x140 [ 540.744170] do_syscall_64+0x4b/0x80 [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}: [ 540.744184] __lock_acquire+0x155f/0x2360 [ 540.744188] lock_acquire+0x10b/0x5c0 [ 540.744190] __mutex_lock+0xb1/0xf80 [ 540.744193] mutex_lock_nested+0x27/0x30 [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs] [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs] [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs] [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs] [ 540.744472] legacy_get_tree+0x38/0x90 [ 540.744475] vfs_get_tree+0x30/0x140 [ 540.744478] fc_mount+0x16/0x60 [ 540.744482] vfs_kern_mount+0x91/0x100 [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs] [ 540.744536] legacy_get_tree+0x38/0x90 [ 540.744537] vfs_get_tree+0x30/0x140 [ 540.744539] path_mount+0x8d8/0x1070 [ 540.744541] do_mount+0x8d/0xc0 [ 540.744543] __x64_sys_mount+0x125/0x160 [ 540.744545] do_syscall_64+0x4b/0x80 [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744551] other info that might help us debug this: [ 540.744552] Possible unsafe locking scenario: [ 540.744553] CPU0 CPU1 [ 540.744554] ---- ---- [ 540.744555] lock(btrfs-chunk-00); [ 540.744557] lock(&fs_devs->device_list_mutex); [ 540.744560] lock(btrfs-chunk-00); [ 540.744562] lock(&fs_devs->device_list_mutex); [ 540.744564] *** DEADLOCK *** [ 540.744565] 3 locks held by mount/2515: [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450 [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs] [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.744708] stack backtrace: [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5 But the device_list_mutex in clone_fs_devices() is redundant, as explained below. Two threads [1] and [2] (below) could lead to clone_fs_device(). [1] open_ctree <== mount sprout fs btrfs_read_chunk_tree() mutex_lock(&uuid_mutex) <== global lock read_one_dev() open_seed_devices() clone_fs_devices() <== seed fs_devices mutex_lock(&orig->device_list_mutex) <== seed fs_devices [2] btrfs_init_new_device() <== sprouting mutex_lock(&uuid_mutex); <== global lock btrfs_prepare_sprout() lockdep_assert_held(&uuid_mutex) clone_fs_devices(seed_fs_device) <== seed fs_devices Both of these threads hold uuid_mutex which is sufficient to protect getting the seed device(s) freed while we are trying to clone it for sprouting [2] or mounting a sprout [1] (as above). A mounted seed device can not free/write/replace because it is read-only. An unmounted seed device can be freed by btrfs_free_stale_devices(), but it needs uuid_mutex. So this patch removes the unnecessary device_list_mutex in clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in clone_fs_devices(). Reported-by: Su Yue <l@damenly.su> Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: delay blkdev_put until after the device removeJosef Bacik
When removing the device we call blkdev_put() on the device once we've removed it, and because we have an EXCL open we need to take the ->open_mutex on the block device to clean it up. Unfortunately during device remove we are holding the sb writers lock, which results in the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #407 Not tainted ------------------------------------------------------ losetup/11595 is trying to acquire lock: ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_put+0x3a/0x220 btrfs_rm_device.cold+0x62/0xe5 btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11595: #0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc21255d4cb So instead save the bdev and do the put once we've dropped the sb writers lock in order to avoid the lockdep recursion. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: update the bdev time directly when closingJosef Bacik
We update the ctime/mtime of a block device when we remove it so that blkid knows the device changed. However we do this by re-opening the block device and calling filp_update_time. This is more correct because it'll call the inode->i_op->update_time if it exists, but the block dev inodes do not do this. Instead call generic_update_time() on the bd_inode in order to avoid the blkdev_open path and get rid of the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #406 Not tainted ------------------------------------------------------ losetup/11596 is trying to acquire lock: ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_get_by_dev.part.0+0x56/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 file_open_name+0xc7/0x170 filp_open+0x2c/0x50 btrfs_scratch_superblocks.part.0+0x10f/0x170 btrfs_rm_device.cold+0xe8/0xed btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11596: #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: reset replace target device to allocation state on closeDesmond Cheong Zhi Xi
This crash was observed with a failed assertion on device close: BTRFS: Transaction aborted (error -28) WARNING: CPU: 1 PID: 3902 at fs/btrfs/extent-tree.c:2150 btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] Modules linked in: btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop CPU: 1 PID: 3902 Comm: kworker/u8:4 Not tainted 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] RIP: 0010:btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] RSP: 0018:ffffb7a5452d7d80 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff97834176a378 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff97835195d388 R13: 0000000005b08000 R14: ffff978385484000 R15: 000000000000016c FS: 0000000000000000(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190d003fe8 CR3: 000000002a81e005 CR4: 0000000000170ea0 Call Trace: flush_space+0x197/0x2f0 [btrfs] btrfs_async_reclaim_metadata_space+0x139/0x300 [btrfs] process_one_work+0x262/0x5e0 worker_thread+0x4c/0x320 ? process_one_work+0x5e0/0x5e0 kthread+0x144/0x170 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 irq event stamp: 19334989 hardirqs last enabled at (19334997): [<ffffffffab0e0c87>] console_unlock+0x2b7/0x400 hardirqs last disabled at (19335006): [<ffffffffab0e0d0d>] console_unlock+0x33d/0x400 softirqs last enabled at (19334900): [<ffffffffaba0030d>] __do_softirq+0x30d/0x574 softirqs last disabled at (19334893): [<ffffffffab0721ec>] irq_exit_rcu+0x12c/0x140 ---[ end trace 45939e308e0dd3c7 ]--- BTRFS: error (device vdd) in btrfs_run_delayed_refs:2150: errno=-28 No space left BTRFS info (device vdd): forced readonly BTRFS warning (device vdd): failed setting block group ro: -30 BTRFS info (device vdd): suspending dev_replace for unmount assertion failed: !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state), in fs/btrfs/volumes.c:1150 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.h:3431! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 3982 Comm: umount Tainted: G W 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs] RSP: 0018:ffffb7a5454c7db8 EFLAGS: 00010246 RAX: 0000000000000068 RBX: ffff978364b91c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff9783523a4c00 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff9783523a4d18 R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000003 FS: 00007f61c8f42800(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190cffa810 CR3: 0000000030b96002 CR4: 0000000000170ea0 Call Trace: btrfs_close_one_device.cold+0x11/0x55 [btrfs] close_fs_devices+0x44/0xb0 [btrfs] btrfs_close_devices+0x48/0x160 [btrfs] generic_shutdown_super+0x69/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x2c/0xa0 cleanup_mnt+0x144/0x1b0 task_work_run+0x59/0xa0 exit_to_user_mode_loop+0xe7/0xf0 exit_to_user_mode_prepare+0xaf/0xf0 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x4a/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae This happens when close_ctree is called while a dev_replace hasn't completed. In close_ctree, we suspend the dev_replace, but keep the replace target around so that we can resume the dev_replace procedure when we mount the root again. This is the call trace: close_ctree(): btrfs_dev_replace_suspend_for_unmount(); btrfs_close_devices(): btrfs_close_fs_devices(): btrfs_close_one_device(): ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); However, since the replace target sticks around, there is a device with BTRFS_DEV_STATE_REPLACE_TGT set on close, and we fail the assertion in btrfs_close_one_device. To fix this, if we come across the replace target device when closing, we should properly reset it back to allocation state. This fix also ensures that if a non-target device has a corrupted state and has the BTRFS_DEV_STATE_REPLACE_TGT bit set, the assertion will still catch the error. Reported-by: David Sterba <dsterba@suse.com> Fixes: b2a616676839 ("btrfs: fix rw device counting in __btrfs_free_extra_devids") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: fix NULL pointer dereference when deleting device by invalid idQu Wenruo
[BUG] It's easy to trigger NULL pointer dereference, just by removing a non-existing device id: # mkfs.btrfs -f -m single -d single /dev/test/scratch1 \ /dev/test/scratch2 # mount /dev/test/scratch1 /mnt/btrfs # btrfs device remove 3 /mnt/btrfs Then we have the following kernel NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 9 PID: 649 Comm: btrfs Not tainted 5.14.0-rc3-custom+ #35 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:btrfs_rm_device+0x4de/0x6b0 [btrfs] btrfs_ioctl+0x18bb/0x3190 [btrfs] ? lock_is_held_type+0xa5/0x120 ? find_held_lock.constprop.0+0x2b/0x80 ? do_user_addr_fault+0x201/0x6a0 ? lock_release+0xd2/0x2d0 ? __x64_sys_ioctl+0x83/0xb0 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae [CAUSE] Commit a27a94c2b0c7 ("btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly") moves the "missing" device path check into btrfs_rm_device(). But btrfs_rm_device() itself can have case where it only receives @devid, with NULL as @device_path. In that case, calling strcmp() on NULL will trigger the NULL pointer dereference. Before that commit, we handle the "missing" case inside btrfs_find_device_by_devspec(), which will not check @device_path at all if @devid is provided, thus no way to trigger the bug. [FIX] Before calling strcmp(), also make sure @device_path is not NULL. Fixes: a27a94c2b0c7 ("btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly") CC: stable@vger.kernel.org # 5.4+ Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: introduce btrfs_search_backwards functionMarcos Paulo de Souza
It's a common practice to start a search using offset (u64)-1, which is the u64 maximum value, meaning that we want the search_slot function to be set in the last item with the same objectid and type. Once we are in this position, it's a matter to start a search backwards by calling btrfs_previous_item, which will check if we'll need to go to a previous leaf and other necessary checks, only to be sure that we are in last offset of the same object and type. The new btrfs_search_backwards function does the all these steps when necessary, and can be used to avoid code duplication. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: simplify return values in btrfs_check_raid_min_devicesAnand Jain
Function btrfs_check_raid_min_devices() returns error code from the enum btrfs_err_code and it starts from 1. So there is no need to check if ret is > 0. So drop this check and also drop the local variable ret. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: allow degenerate raid0/raid10David Sterba
The data on raid0 and raid10 are supposed to be spread over multiple devices, so the minimum constraints are set to 2 and 4 respectively. This is an artificial limit and there's some interest to remove it. Change this to allow raid0 on one device and raid10 on two devices. This works as expected eg. when converting or removing devices. The only difference is when raid0 on two devices gets one device removed. Unpatched would silently create a single profile, while newly it would be raid0. The motivation is to allow to preserve the profile type as long as it possible for some intermediate state (device removal, conversion), or when there are disks of different size, with raid0 the otherwise unusable space of the last device will be used too. Similarly for raid10, though the two largest devices would need to be the same. Unpatched kernel will mount and use the degenerate profiles just fine but won't allow any operation that would not satisfy the stricter device number constraints, eg. not allowing to go from 3 to 2 devices for raid10 or various profile conversions. Example output: # btrfs fi us -T . Overall: Device size: 10.00GiB Device allocated: 1.01GiB Device unallocated: 8.99GiB Device missing: 0.00B Used: 200.61MiB Free (estimated): 9.79GiB (min: 9.79GiB) Free (statfs, df): 9.79GiB Data ratio: 1.00 Metadata ratio: 1.00 Global reserve: 3.25MiB (used: 0.00B) Multiple profiles: no Data Metadata System Id Path RAID0 single single Unallocated -- ---------- --------- --------- -------- ----------- 1 /dev/sda10 1.00GiB 8.00MiB 1.00MiB 8.99GiB -- ---------- --------- --------- -------- ----------- Total 1.00GiB 8.00MiB 1.00MiB 8.99GiB Used 200.25MiB 352.00KiB 16.00KiB # btrfs dev us . /dev/sda10, ID: 1 Device size: 10.00GiB Device slack: 0.00B Data,RAID0/1: 1.00GiB Metadata,single: 8.00MiB System,single: 1.00MiB Unallocated: 8.99GiB Note "Data,RAID0/1", with btrfs-progs 5.13+ the number of devices per profile is printed. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: subpage: reject raid56 filesystem and profile conversionQu Wenruo
RAID56 is not only unsafe due to its write-hole problem, but also has tons of hardcoded PAGE_SIZE. Disable it for subpage support for now. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: constify and cleanup variables in comparatorsDavid Sterba
Comparators just read the data and thus get const parameters. This should be also preserved by the local variables, update all comparators passed to sort or bsearch. Cleanups: - unnecessary casts are dropped - btrfs_cmp_device_free_bytes is cleaned up to follow the common pattern and 'inline' is dropped as the function address is taken Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: simplify data stripe calculation helpersDavid Sterba
There are two helpers doing the same calculations based on nparity and ncopies. calc_data_stripes can be simplified into one expression, so far we don't have profile with both copies and parity, so there's no effective change. calc_stripe_length should reuse the helper and not repeat the same calculation. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: merge alloc_device helpersDavid Sterba
The device allocation is split to two functions, but one just calls the other and they're very far in the file. Merge them together. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: uninline btrfs_bg_flags_to_raid_indexDavid Sterba
The helper does a simple translation from block group flags to index to the btrfs_raid_array table. There's no apparent reason to inline the function, the translation happens usually once per function and is not called in a loop. Making it a proper function saves quite some binary code (x86_64, release config): text data bss dec hex filename 1164011 19253 14912 1198176 124860 pre/btrfs.ko 1161559 19253 14912 1195724 123ecc post/btrfs.ko DELTA: -2451 Also add the const attribute as there are no side effects, this could help compiler to optimize a few things without the function body. Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: use btrfs_next_leaf instead of btrfs_next_item when slots > nritemsMarcos Paulo de Souza
After calling btrfs_search_slot is a common practice to check if the slot found isn't bigger than number of slots in the current leaf, and if so, search for the same key in the next leaf by calling btrfs_next_leaf, which calls btrfs_next_old_leaf to do the job. Calling btrfs_next_item in the same situation would end up in the same code flow, since * btrfs_next_item * btrfs_next_old_item * if slot >= nritems(curr_leaf) btrfs_next_old_leaf Change btrfs_verify_dev_extents and calculate_emulated_zone_size functions to use btrfs_next_leaf in the same situation. Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23btrfs: make btrfs_finish_chunk_alloc private to block-group.cNikolay Borisov
One of the final things that must be done to add a new chunk is inserting its device extent items in the device tree. They describe the portion of allocated device physical space during phase 1 of chunk allocation. This is currently done in btrfs_finish_chunk_alloc whose name isn't very informative. What's more, this function is only used in block-group.c but is defined as public. There isn't anything special about it that would warrant it being defined in volumes.c. Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to block-group.c, make the former static and rename both functions to insert_dev_extents and insert_dev_extent respectively. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-07-30Merge tag 'for-5.14-rc3-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix -Warray-bounds warning, to help external patchset to make it default treewide - fix writeable device accounting (syzbot report) - fix fsync and log replay after a rename and inode eviction - fix potentially lost error code when submitting multiple bios for compressed range * tag 'for-5.14-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: calculate number of eb pages properly in csum_tree_block btrfs: fix rw device counting in __btrfs_free_extra_devids btrfs: fix lost inode on log replay after mix of fsync, rename and inode eviction btrfs: mark compressed range uptodate only if all bio succeed
2021-07-28btrfs: fix rw device counting in __btrfs_free_extra_devidsDesmond Cheong Zhi Xi
When removing a writeable device in __btrfs_free_extra_devids, the rw device count should be decremented. This error was caught by Syzbot which reported a warning in close_fs_devices: WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 Modules linked in: CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168 RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293 RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128 R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180 open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693 btrfs_fill_super fs/btrfs/super.c:1382 [inline] btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 fc_mount fs/namespace.c:993 [inline] vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023 btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Because fs_devices->rw_devices was not 0 after closing all devices. Here is the call trace that was observed: btrfs_mount_root(): btrfs_scan_one_device(): device_list_add(); <---------------- device added btrfs_open_devices(): open_fs_devices(): btrfs_open_one_device(); <-------- writable device opened, rw device count ++ btrfs_fill_super(): open_ctree(): btrfs_free_extra_devids(): __btrfs_free_extra_devids(); <--- writable device removed, rw device count not decremented fail_tree_roots: btrfs_close_devices(): close_fs_devices(); <------- rw device count off by 1 As a note, prior to commit cf89af146b7e ("btrfs: dev-replace: fail mount if we don't have replace item with target device"), rw_devices was decremented on removing a writable device in __btrfs_free_extra_devids only if the BTRFS_DEV_STATE_REPLACE_TGT bit was not set for the device. However, this check does not need to be reinstated as it is now redundant and incorrect. In __btrfs_free_extra_devids, we skip removing the device if it is the target for replacement. This is done by checking whether device->devid == BTRFS_DEV_REPLACE_DEVID. Since BTRFS_DEV_STATE_REPLACE_TGT is set only on the device with devid BTRFS_DEV_REPLACE_DEVID, no devices should have the BTRFS_DEV_STATE_REPLACE_TGT bit set after the check, and so it's redundant to test for that bit. Additionally, following commit 82372bc816d7 ("Btrfs: make the logic of source device removing more clear"), rw_devices is incremented whenever a writeable device is added to the alloc list (including the target device in btrfs_dev_replace_finishing), so all removals of writable devices from the alloc list should also be accompanied by a decrement to rw_devices. Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com Fixes: cf89af146b7e ("btrfs: dev-replace: fail mount if we don't have replace item with target device") CC: stable@vger.kernel.org # 5.10+ Tested-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-07-13Merge tag 'for-5.14-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs zoned mode fixes from David Sterba: - fix deadlock when allocating system chunk - fix wrong mutex unlock on an error path - fix extent map splitting for append operation - update and fix message reporting unusable chunk space - don't block when background zone reclaim runs with balance in parallel * tag 'for-5.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: zoned: fix wrong mutex unlock on failure to allocate log root tree btrfs: don't block if we can't acquire the reclaim lock btrfs: properly split extent_map for REQ_OP_ZONE_APPEND btrfs: rework chunk allocation to avoid exhaustion of the system chunk array btrfs: fix deadlock with concurrent chunk allocations involving system chunks btrfs: zoned: print unusable percentage when reclaiming block groups btrfs: zoned: fix types for u64 division in btrfs_reclaim_bgs_work
2021-07-07btrfs: rework chunk allocation to avoid exhaustion of the system chunk arrayFilipe Manana
Commit eafa4fd0ad0607 ("btrfs: fix exhaustion of the system chunk array due to concurrent allocations") fixed a problem that resulted in exhausting the system chunk array in the superblock when there are many tasks allocating chunks in parallel. Basically too many tasks enter the first phase of chunk allocation without previous tasks having finished their second phase of allocation, resulting in too many system chunks being allocated. That was originally observed when running the fallocate tests of stress-ng on a PowerPC machine, using a node size of 64K. However that commit also introduced a deadlock where a task in phase 1 of the chunk allocation waited for another task that had allocated a system chunk to finish its phase 2, but that other task was waiting on an extent buffer lock held by the first task, therefore resulting in both tasks not making any progress. That change was later reverted by a patch with the subject "btrfs: fix deadlock with concurrent chunk allocations involving system chunks", since there is no simple and short solution to address it and the deadlock is relatively easy to trigger on zoned filesystems, while the system chunk array exhaustion is not so common. This change reworks the chunk allocation to avoid the system chunk array exhaustion. It accomplishes that by making the first phase of chunk allocation do the updates of the device items in the chunk btree and the insertion of the new chunk item in the chunk btree. This is done while under the protection of the chunk mutex (fs_info->chunk_mutex), in the same critical section that checks for available system space, allocates a new system chunk if needed and reserves system chunk space. This way we do not have chunk space reserved until the second phase completes. The same logic is applied to chunk removal as well, since it keeps reserved system space long after it is done updating the chunk btree. For direct allocation of system chunks, the previous behaviour remains, because otherwise we would deadlock on extent buffers of the chunk btree. Changes to the chunk btree are by large done by chunk allocation and chunk removal, which first reserve chunk system space and then later do changes to the chunk btree. The other remaining cases are uncommon and correspond to adding a device, removing a device and resizing a device. All these other cases do not pre-reserve system space, they modify the chunk btree right away, so they don't hold reserved space for a long period like chunk allocation and chunk removal do. The diff of this change is huge, but more than half of it is just addition of comments describing both how things work regarding chunk allocation and removal, including both the new behavior and the parts of the old behavior that did not change. CC: stable@vger.kernel.org # 5.12+ Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Tested-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-30Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: - disk events cleanup (Christoph) - gendisk and request queue allocation simplifications (Christoph) - bdev_disk_changed cleanups (Christoph) - IO priority improvements (Bart) - Chained bio completion trace fix (Edward) - blk-wbt fixes (Jan) - blk-wbt enable/disable fix (Zhang) - Scheduler dispatch improvements (Jan, Ming) - Shared tagset scheduler improvements (John) - BFQ updates (Paolo, Luca, Pietro) - BFQ lock inversion fix (Jan) - Documentation improvements (Kir) - CLONE_IO block cgroup fix (Tejun) - Remove of ancient and deprecated block dump feature (zhangyi) - Discard merge fix (Ming) - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas, Yang) * tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits) block: fix discard request merge block/mq-deadline: Remove a WARN_ON_ONCE() call blk-mq: update hctx->dispatch_busy in case of real scheduler blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block: pass a gendisk to bdev_disk_changed block: move bdev_disk_changed block: add the events* attributes to disk_attrs block: move the disk events code to a separate file block: fix trace completion for chained bio block/partitions/msdos: Fix typo inidicator -> indicator block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising blk-wbt: make sure throttle is enabled properly blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() ...
2021-06-22btrfs: ensure relocation never runs while we have send operations runningFilipe Manana
Relocation and send do not play well together because while send is running a block group can be relocated, a transaction committed and the respective disk extents get re-allocated and written to or discarded while send is about to do something with the extents. This was explained in commit 9e967495e0e0ae ("Btrfs: prevent send failures and crashes due to concurrent relocation"), which prevented balance and send from running in parallel but it did not address one remaining case where chunk relocation can happen: shrinking a device (and device deletion which shrinks a device's size to 0 before deleting the device). We also have now one more case where relocation is triggered: on zoned filesystems partially used block groups get relocated by a background thread, introduced in commit 18bb8bbf13c183 ("btrfs: zoned: automatically reclaim zones"). So make sure that instead of preventing balance from running when there are ongoing send operations, we prevent relocation from happening. This uses the infrastructure recently added by a patch that has the subject: "btrfs: add cancellable chunk relocation support". Also it adds a spinlock used exclusively for the exclusivity between send and relocation, as before fs_info->balance_mutex was used, which would make an attempt to run send to block waiting for balance to finish, which can take a lot of time on large filesystems. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-22btrfs: fix typos in commentsDavid Sterba
Fix typos that have snuck in since the last round. Found by codespell. Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21btrfs: remove the unused parameter @len for btrfs_bio_fits_in_stripe()Qu Wenruo
The parameter @len is not really used in btrfs_bio_fits_in_stripe(), just remove it. It got removed in 420343131970 ("btrfs: let callers of btrfs_get_io_geometry pass the em"), before that btrfs_get_chunk_map utilized it. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21btrfs: remove stale comment for argument seed of btrfs_find_deviceSu Yue
Commit b2598edf8b36 ("btrfs: remove unused argument seed from btrfs_find_device") removed the argument seed from btrfs_find_device but forgot the comment, so remove it. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Su Yue <l@damenly.su> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-01block: move bd_mutex to struct gendiskChristoph Hellwig
Replace the per-block device bd_mutex with a per-gendisk open_mutex, thus simplifying locking wherever we deal with partitions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-17Merge tag 'for-5.13-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more fixes: - fix fiemap to print extents that could get misreported due to internal extent splitting and logical merging for fiemap output - fix RCU stalls during delayed iputs - fix removed dentries still existing after log is synced" * tag 'for-5.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix removed dentries still existing after log is synced btrfs: return whole extents in fiemap btrfs: avoid RCU stalls while running delayed iputs btrfs: return 0 for dev_extent_hole_check_zoned hole_start in case of error
2021-05-14btrfs: return 0 for dev_extent_hole_check_zoned hole_start in case of errorJohannes Thumshirn
Commit 7000babddac6 ("btrfs: assign proper values to a bool variable in dev_extent_hole_check_zoned") assigned false to the hole_start parameter of dev_extent_hole_check_zoned(). The hole_start parameter is not boolean and returns the start location of the found hole. Fixes: 7000babddac6 ("btrfs: assign proper values to a bool variable in dev_extent_hole_check_zoned") Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-27Merge tag 'cfi-v5.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull CFI on arm64 support from Kees Cook: "This builds on last cycle's LTO work, and allows the arm64 kernels to be built with Clang's Control Flow Integrity feature. This feature has happily lived in Android kernels for almost 3 years[1], so I'm excited to have it ready for upstream. The wide diffstat is mainly due to the treewide fixing of mismatched list_sort prototypes. Other things in core kernel are to address various CFI corner cases. The largest code portion is the CFI runtime implementation itself (which will be shared by all architectures implementing support for CFI). The arm64 pieces are Acked by arm64 maintainers rather than coming through the arm64 tree since carrying this tree over there was going to be awkward. CFI support for x86 is still under development, but is pretty close. There are a handful of corner cases on x86 that need some improvements to Clang and objtool, but otherwise works well. Summary: - Clean up list_sort prototypes (Sami Tolvanen) - Introduce CONFIG_CFI_CLANG for arm64 (Sami Tolvanen)" * tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: allow CONFIG_CFI_CLANG to be selected KVM: arm64: Disable CFI for nVHE arm64: ftrace: use function_nocfi for ftrace_call arm64: add __nocfi to __apply_alternatives arm64: add __nocfi to functions that jump to a physical address arm64: use function_nocfi with __pa_symbol arm64: implement function_nocfi psci: use function_nocfi for cpu_resume lkdtm: use function_nocfi treewide: Change list_sort to use const pointers bpf: disable CFI in dispatcher functions kallsyms: strip ThinLTO hashes from static functions kthread: use WARN_ON_FUNCTION_MISMATCH workqueue: use WARN_ON_FUNCTION_MISMATCH module: ensure __cfi_check alignment mm: add generic function_nocfi macro cfi: add __cficanonical add support for Clang CFI
2021-04-20btrfs: zoned: automatically reclaim zonesJohannes Thumshirn
When a file gets deleted on a zoned file system, the space freed is not returned back into the block group's free space, but is migrated to zone_unusable. As this zone_unusable space is behind the current write pointer it is not possible to use it for new allocations. In the current implementation a zone is reset once all of the block group's space is accounted as zone unusable. This behaviour can lead to premature ENOSPC errors on a busy file system. Instead of only reclaiming the zone once it is completely unusable, kick off a reclaim job once the amount of unusable bytes exceeds a user configurable threshold between 51% and 100%. It can be set per mounted filesystem via the sysfs tunable bg_reclaim_threshold which is set to 75% by default. Similar to reclaiming unused block groups, these dirty block groups are added to a to_reclaim list and then on a transaction commit, the reclaim process is triggered but after we deleted unused block groups, which will free space for the relocation process. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: rename delete_unused_bgs_mutex to reclaim_bgs_lockJohannes Thumshirn
As a preparation for extending the block group deletion use case, rename the unused_bgs_mutex to reclaim_bgs_lock. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: zoned: reset zones of relocated block groupsJohannes Thumshirn
When relocating a block group the freed up space is not discarded in one big block, but each extent is discarded on its own with -odisard=sync. For a zoned filesystem we need to discard the whole block group at once, so btrfs_discard_extent() will translate the discard into a REQ_OP_ZONE_RESET operation, which then resets the device's zone. Failure to reset the zone is not fatal error. Discussion about the approach and regarding transaction blocking: https://lore.kernel.org/linux-btrfs/CAL3q7H4SjS_d5rBepfTMhU8Th3bJzdmyYd0g4Z60yUgC_rC_ZA@mail.gmail.com/ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: more graceful errors/warnings on 32bit systems when reaching limitsQu Wenruo
Btrfs uses internally mapped u64 address space for all its metadata. Due to the page cache limit on 32bit systems, btrfs can't access metadata at or beyond (ULONG_MAX + 1) << PAGE_SHIFT. See how MAX_LFS_FILESIZE and page::index are defined. This is 16T for 4K page size while 256T for 64K page size. Users can have a filesystem which doesn't have metadata beyond the boundary at mount time, but later balance can cause it to create metadata beyond the boundary. And modification to MM layer is unrealistic just for such minor use case. We can't do more than to prevent mounting such filesystem or warn early when the numbers are still within the limits. To address such problem, this patch will introduce the following checks: - Mount time rejection This will reject any fs which has metadata chunk at or beyond the boundary. - Mount time early warning If there is any metadata chunk beyond 5/8th of the boundary, we do an early warning and hope the end user will see it. - Runtime extent buffer rejection If we're going to allocate an extent buffer at or beyond the boundary, reject such request with EOVERFLOW. This is definitely going to cause problems like transaction abort, but we have no better ways. - Runtime extent buffer early warning If an extent buffer beyond 5/8th of the max file size is allocated, do an early warning. Above error/warning message will only be printed once for each fs to reduce dmesg flood. If the mount is rejected, the filesystem will be mountable only on a 64bit host. Link: https://lore.kernel.org/linux-btrfs/1783f16d-7a28-80e6-4c32-fdf19b705ed0@gmx.com/ Reported-by: Erik Jensen <erikjensen@rkjnsn.net> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: zoned: bail out in btrfs_alloc_chunk for bad inputArnd Bergmann
gcc complains that the ctl->max_chunk_size member might be used uninitialized when none of the three conditions for initializing it in init_alloc_chunk_ctl_policy_zoned() are true: In function ‘init_alloc_chunk_ctl_policy_zoned’, inlined from ‘init_alloc_chunk_ctl’ at fs/btrfs/volumes.c:5023:3, inlined from ‘btrfs_alloc_chunk’ at fs/btrfs/volumes.c:5340:2: include/linux/compiler-gcc.h:48:45: error: ‘ctl.max_chunk_size’ may be used uninitialized [-Werror=maybe-uninitialized] 4998 | ctl->max_chunk_size = min(limit, ctl->max_chunk_size); | ^~~ fs/btrfs/volumes.c: In function ‘btrfs_alloc_chunk’: fs/btrfs/volumes.c:5316:32: note: ‘ctl’ declared here 5316 | struct alloc_chunk_ctl ctl; | ^~~ If we ever get into this condition, something is seriously wrong, as validity is checked in the callers btrfs_alloc_chunk init_alloc_chunk_ctl init_alloc_chunk_ctl_policy_zoned so the same logic as in init_alloc_chunk_ctl_policy_regular() and a few other places should be applied. This avoids both further data corruption, and the compile-time warning. Fixes: 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: assign proper values to a bool variable in dev_extent_hole_check_zonedJiapeng Chong
Fix the following coccicheck warnings: ./fs/btrfs/volumes.c:1462:10-11: WARNING: return of 0/1 in function 'dev_extent_hole_check_zoned' with return type bool. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-08treewide: Change list_sort to use const pointersSami Tolvanen
list_sort() internally casts the comparison function passed to it to a different type with constant struct list_head pointers, and uses this pointer to call the functions, which trips indirect call Control-Flow Integrity (CFI) checking. Instead of removing the consts, this change defines the list_cmp_func_t type and changes the comparison function types of all list_sort() callers to use const pointers, thus avoiding type mismatches. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
2021-03-25Merge tag 'for-5.12-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Fixes for issues that have some user visibility and are simple enough for this time of development cycle: - a few fixes for rescue= mount option, adding more checks for missing trees - fix sleeping in atomic context on qgroup deletion - fix subvolume deletion on mount - fix build with M= syntax - fix checksum mismatch error message for direct io" * tag 'for-5.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix check_data_csum() error message for direct I/O btrfs: fix sleep while in non-sleep context during qgroup removal btrfs: fix subvolume/snapshot deletion not triggered on mount btrfs: fix build when using M=fs/btrfs btrfs: do not initialize dev replace for bad dev root btrfs: initialize device::fs_info always btrfs: do not initialize dev stats if we have no dev_root btrfs: zoned: remove outdated WARN_ON in direct IO
2021-03-17btrfs: do not initialize dev stats if we have no dev_rootJosef Bacik
Neal reported a panic trying to use -o rescue=all BUG: kernel NULL pointer dereference, address: 0000000000000030 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 4095 Comm: mount Not tainted 5.11.0-0.rc7.149.fc34.x86_64 #1 RIP: 0010:btrfs_device_init_dev_stats+0x4c/0x1f0 RSP: 0018:ffffa60285fbfb68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88b88f806498 RCX: ffff88b82e7a2a10 RDX: ffffa60285fbfb97 RSI: ffff88b82e7a2a10 RDI: 0000000000000000 RBP: ffff88b88f806b3c R08: 0000000000000000 R09: 0000000000000000 R10: ffff88b82e7a2a10 R11: 0000000000000000 R12: ffff88b88f806a00 R13: ffff88b88f806478 R14: ffff88b88f806a00 R15: ffff88b82e7a2a10 FS: 00007f698be1ec40(0000) GS:ffff88b937e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000092c9c006 CR4: 00000000003706f0 Call Trace: ? btrfs_init_dev_stats+0x1f/0xf0 btrfs_init_dev_stats+0x62/0xf0 open_ctree+0x1019/0x15ff btrfs_mount_root.cold+0x13/0xfa legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x131/0x3d0 ? legacy_get_tree+0x27/0x40 ? btrfs_show_options+0x640/0x640 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x441/0xa80 __x64_sys_mount+0xf4/0x130 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f698c04e52e This happens because we unconditionally attempt to initialize device stats on mount, but we may not have been able to read the device root. Fix this by skipping initializing the device stats if we do not have a device root. Reported-by: Neal Gompa <ngompa13@gmail.com> CC: stable@vger.kernel.org # 5.11+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-21Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "Another nice round of removing more code than what is added, mostly due to Christoph's relentless pursuit of tech debt removal/cleanups. This pull request contains: - Two series of BFQ improvements (Paolo, Jan, Jia) - Block iov_iter improvements (Pavel) - bsg error path fix (Pan) - blk-mq scheduler improvements (Jan) - -EBUSY discard fix (Jan) - bvec allocation improvements (Ming, Christoph) - bio allocation and init improvements (Christoph) - Store bdev pointer in bio instead of gendisk + partno (Christoph) - Block trace point cleanups (Christoph) - hard read-only vs read-only split (Christoph) - Block based swap cleanups (Christoph) - Zoned write granularity support (Damien) - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)" * tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits) mm: simplify swapdev_block sd_zbc: clear zone resources for non-zoned case block: introduce blk_queue_clear_zone_settings() zonefs: use zone write granularity as block size block: introduce zone_write_granularity limit block: use blk_queue_set_zoned in add_partition() nullb: use blk_queue_set_zoned() to setup zoned devices nvme: cleanup zone information initialization block: document zone_append_max_bytes attribute block: use bi_max_vecs to find the bvec pool md/raid10: remove dead code in reshape_request block: mark the bio as cloned in bio_iov_bvec_set block: set BIO_NO_PAGE_REF in bio_iov_bvec_set block: remove a layer of indentation in bio_iov_iter_get_pages block: turn the nr_iovecs argument to bio_alloc* into an unsigned short block: remove the 1 and 4 vec bvec_slabs entries block: streamline bvec_alloc block: factor out a bvec_alloc_gfp helper block: move struct biovec_slab to bio.c block: reuse BIO_INLINE_VECS for integrity bvecs ...
2021-02-09btrfs: zoned: relocate block group to repair IO failure in zoned filesystemsNaohiro Aota
When a bad checksum is found and if the filesystem has a mirror of the damaged data, we read the correct data from the mirror and writes it to damaged blocks. This however, violates the sequential write constraints of a zoned block device. We can consider three methods to repair an IO failure in zoned filesystems: (1) Reset and rewrite the damaged zone (2) Allocate new device extent and replace the damaged device extent to the new extent (3) Relocate the corresponding block group Method (1) is most similar to a behavior done with regular devices. However, it also wipes non-damaged data in the same device extent, and so it unnecessary degrades non-damaged data. Method (2) is much like device replacing but done in the same device. It is safe because it keeps the device extent until the replacing finish. However, extending device replacing is non-trivial. It assumes "src_dev->physical == dst_dev->physical". Also, the extent mapping replacing function should be extended to support replacing device extent position in one device. Method (3) invokes relocation of the damaged block group and is straightforward to implement. It relocates all the mirrored device extents, so it potentially is a more costly operation than method (1) or (2). But it relocates only used extents which reduce the total IO size. Let's apply method (3) for now. In the future, we can extend device-replace and apply method (2). For protecting a block group gets relocated multiple time with multiple IO errors, this commit introduces "relocating_repair" bit to show it's now relocating to repair IO failures. Also it uses a new kthread "btrfs-relocating-repair", not to block IO path with relocating process. This commit also supports repairing in the scrub process. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>