- 24 Feb, 2017 1 commit
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Robbie Ko authored
Under certain situations, an incremental send operation can fail due to a premature attempt to create a new top level inode (a direct child of the subvolume/snapshot root) whose name collides with another inode that was removed from the send snapshot. Consider the following example scenario. Parent snapshot: . (ino 256, gen 8) |---- a1/ (ino 257, gen 9) |---- a2/ (ino 258, gen 9) Send snapshot: . (ino 256, gen 3) |---- a2/ (ino 257, gen 7) In this scenario, when receiving the incremental send stream, the btrfs receive command fails like this (ran in verbose mode, -vv argument): rmdir a1 mkfile o257-7-0 rename o257-7-0 -> a2 ERROR: rename o257-7-0 -> a2 failed: Is a directory What happens when computing the incremental send stream is: 1) An operation to remove the directory with inode number 257 and generation 9 is issued. 2) An operation to create the inode with number 257 and generation 7 is issued. This creates the inode with an orphanized name of "o257-7-0". 3) An operation rename the new inode 257 to its final name, "a2", is issued. This is incorrect because inode 258, which has the same name and it's a child of the same parent (root inode 256), was not yet processed and therefore no rmdir operation for it was yet issued. The rename operation is issued because we fail to detect that the name of the new inode 257 collides with inode 258, because their parent, a subvolume/snapshot root (inode 256) has a different generation in both snapshots. So fix this by ignoring the generation value of a parent directory that matches a root inode (number 256) when we are checking if the name of the inode currently being processed collides with the name of some other inode that was not yet processed. We can achieve this scenario of different inodes with the same number but different generation values either by mounting a filesystem with the inode cache option (-o inode_cache) or by creating and sending snapshots across different filesystems, like in the following example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a1 $ mkdir /mnt/a2 $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/1.snap $ umount /mnt $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ touch /mnt/a2 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs receive /mnt -f /tmp/1.snap # Take note that once the filesystem is created, its current # generation has value 7 so the inode from the second snapshot has # a generation value of 7. And after receiving the first snapshot # the filesystem is at a generation value of 10, because the call to # create the second snapshot bumps the generation to 8 (the snapshot # creation ioctl does a transaction commit), the receive command calls # the snapshot creation ioctl to create the first snapshot, which bumps # the filesystem's generation to 9, and finally when the receive # operation finishes it calls an ioctl to transition the first snapshot # (snap1) from RW mode to RO mode, which does another transaction commit # and bumps the filesystem's generation to 10. $ rm -f /tmp/1.snap $ btrfs send /mnt/snap1 -f /tmp/1.snap $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap $ umount /mnt $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ btrfs receive /mnt /tmp/1.snap # Receive of snapshot snap2 used to fail. $ btrfs receive /mnt /tmp/2.snap Signed-off-by:
Robbie Ko <robbieko@synology.com> Reviewed-by:
Filipe Manana <fdmanana@suse.com> [Rewrote changelog to be more precise and clear] Signed-off-by:
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- 22 Feb, 2017 2 commits
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Liu Bo authored
'BTRFS_ORDERED_REGULAR' was introduced for the cow case in patch 'Btrfs: specify a new ordered extent type for create_io_em', but it missed the directIO cow case. Signed-off-by:
Liu Bo <bo.li.liu@oracle.com> Signed-off-by:
Chris Mason <clm@fb.com>
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Filipe Manana authored
If we are deduping two ranges of the same file we need to make sure that we lock all pages in ascending order, that is, lock first the pages from the range with lower offset and then the pages from the other range, as otherwise we can deadlock with a concurrent task that is starting delalloc (writeback). Example trace: [74073.052218] INFO: task kworker/u32:10:17997 blocked for more than 120 seconds. [74073.053889] Tainted: G W 4.9.0-rc7-btrfs-next-36+ #1 [74073.055071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [74073.056696] kworker/u32:10 D 0 17997 2 0x00000000 [74073.058606] Workqueue: writeback wb_workfn (flush-btrfs-53176) [74073.061370] ffff880031e79858 ffff8802159d2580 ffff880237004580 ffff880031e79240 [74073.064784] ffff88023f4978c0 ffffc9000817b638 ffffffff814c15e1 0000000000000000 [74073.068386] ffff88023f4978d8 ffff88023f4978c0 000000000017b620 ffff880031e79240 [74073.071712] Call Trace: [74073.072884] [<ffffffff814c15e1>] ? __schedule+0x48f/0x6f4 [74073.075395] [<ffffffff814c1c8b>] ? bit_wait+0x2f/0x2f [74073.077511] [<ffffffff814c18d2>] schedule+0x8c/0xa0 [74073.079440] [<ffffffff814c4b36>] schedule_timeout+0x43/0xff [74073.081637] [<ffffffff8110953e>] ? time_hardirqs_on+0x9/0x14 [74073.083809] [<ffffffff81095c67>] ? trace_hardirqs_on_caller+0x16/0x197 [74073.086314] [<ffffffff810bde98>] ? timekeeping_get_ns+0x1e/0x32 [74073.100654] [<ffffffff810be048>] ? ktime_get+0x41/0x52 [74073.102619] [<ffffffff814c10f0>] io_schedule_timeout+0xa0/0x102 [74073.104771] [<ffffffff814c10f0>] ? io_schedule_timeout+0xa0/0x102 [74073.106969] [<ffffffff814c1ca6>] bit_wait_io+0x1b/0x39 [74073.108954] [<ffffffff814c1fb8>] __wait_on_bit_lock+0x4f/0x99 [74073.110981] [<ffffffff8112b692>] __lock_page+0x6b/0x6d [74073.112833] [<ffffffff8108ceb4>] ? autoremove_wake_function+0x3a/0x3a [74073.115010] [<ffffffffa031178b>] lock_page+0x2f/0x32 [btrfs] [74073.116999] [<ffffffffa0311d9f>] lock_delalloc_pages+0xc7/0x1a0 [btrfs] [74073.119243] [<ffffffffa0313d15>] find_lock_delalloc_range+0xc3/0x1a4 [btrfs] [74073.121636] [<ffffffffa0313e81>] writepage_delalloc.isra.31+0x8b/0x134 [btrfs] [74073.124229] [<ffffffffa0315d69>] __extent_writepage+0x1c1/0x2bf [btrfs] [74073.126372] [<ffffffffa03160f2>] extent_write_cache_pages.isra.30.constprop.49+0x28b/0x36c [btrfs] [74073.129371] [<ffffffffa03165b9>] extent_writepages+0x4b/0x5c [btrfs] [74073.131440] [<ffffffffa02fcb59>] ? insert_reserved_file_extent.constprop.42+0x261/0x261 [btrfs] [74073.134303] [<ffffffff811b4ce4>] ? writeback_sb_inodes+0xe0/0x4a1 [74073.136298] [<ffffffffa02fab7f>] btrfs_writepages+0x28/0x2a [btrfs] [74073.138248] [<ffffffff81138200>] do_writepages+0x23/0x2c [74073.139910] [<ffffffff811b3cab>] __writeback_single_inode+0x105/0x6d2 [74073.142003] [<ffffffff811b4e96>] writeback_sb_inodes+0x292/0x4a1 [74073.136298] [<ffffffffa02fab7f>] btrfs_writepages+0x28/0x2a [btrfs] [74073.138248] [<ffffffff81138200>] do_writepages+0x23/0x2c [74073.139910] [<ffffffff811b3cab>] __writeback_single_inode+0x105/0x6d2 [74073.142003] [<ffffffff811b4e96>] writeback_sb_inodes+0x292/0x4a1 [74073.143911] [<ffffffff811b511b>] __writeback_inodes_wb+0x76/0xae [74073.145787] [<ffffffff811b53ca>] wb_writeback+0x1cc/0x4d7 [74073.147452] [<ffffffff811b60cd>] wb_workfn+0x194/0x37d [74073.149084] [<ffffffff811b60cd>] ? wb_workfn+0x194/0x37d [74073.150726] [<ffffffff8106ce77>] ? process_one_work+0x154/0x4e4 [74073.152694] [<ffffffff8106cf96>] process_one_work+0x273/0x4e4 [74073.154452] [<ffffffff8106d6db>] worker_thread+0x1eb/0x2ca [74073.156138] [<ffffffff8106d4f0>] ? rescuer_thread+0x2b6/0x2b6 [74073.157837] [<ffffffff81072a81>] kthread+0xd5/0xdd [74073.159339] [<ffffffff810729ac>] ? __kthread_unpark+0x5a/0x5a [74073.161088] [<ffffffff814c6257>] ret_from_fork+0x27/0x40 [74073.162680] INFO: lockdep is turned off. [74073.163855] INFO: task do-dedup:30264 blocked for more than 120 seconds. [74073.181180] Tainted: G W 4.9.0-rc7-btrfs-next-36+ #1 [74073.181180] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [74073.185296] fdm-stress D 0 30264 29974 0x00000000 [74073.186810] ffff880089595118 ffff880211b8eac0 ffff880237030380 ffff880089594b00 [74073.188998] ffff88023f2978c0 ffffc900063abb68 ffffffff814c15e1 0000000000000000 [74073.191070] ffff88023f2978d8 ffff88023f2978c0 00000000003abb50 ffff880089594b00 [74073.193286] Call Trace: [74073.193990] [<ffffffff814c15e1>] ? __schedule+0x48f/0x6f4 [74073.195418] [<ffffffff814c1c8b>] ? bit_wait+0x2f/0x2f [74073.196796] [<ffffffff814c18d2>] schedule+0x8c/0xa0 [74073.198163] [<ffffffff814c4b36>] schedule_timeout+0x43/0xff [74073.199621] [<ffffffff81095df5>] ? trace_hardirqs_on+0xd/0xf [74073.201100] [<ffffffff810bde98>] ? timekeeping_get_ns+0x1e/0x32 [74073.202686] [<ffffffff810be048>] ? ktime_get+0x41/0x52 [74073.204051] [<ffffffff814c10f0>] io_schedule_timeout+0xa0/0x102 [74073.205585] [<ffffffff814c10f0>] ? io_schedule_timeout+0xa0/0x102 [74073.207123] [<ffffffff814c1ca6>] bit_wait_io+0x1b/0x39 [74073.208238] [<ffffffff814c1fb8>] __wait_on_bit_lock+0x4f/0x99 [74073.208871] [<ffffffff8112b692>] __lock_page+0x6b/0x6d [74073.209430] [<ffffffff8108ceb4>] ? autoremove_wake_function+0x3a/0x3a [74073.210101] [<ffffffff8112b800>] lock_page+0x2f/0x32 [74073.210636] [<ffffffff8112c502>] pagecache_get_page+0x5e/0x153 [74073.211270] [<ffffffffa03257eb>] gather_extent_pages+0x4e/0x109 [btrfs] [74073.212166] [<ffffffffa032a04c>] btrfs_dedupe_file_range+0x1e1/0x4dd [btrfs] [74073.213257] [<ffffffff8118d9b5>] vfs_dedupe_file_range+0x1c1/0x221 [74073.214086] [<ffffffff8119e0c4>] do_vfs_ioctl+0x442/0x600 [74073.214767] [<ffffffff811a7874>] ? rcu_read_unlock+0x5b/0x5d [74073.215619] [<ffffffff811a7953>] ? __fget+0x6b/0x77 [74073.216338] [<ffffffff8119e2d9>] SyS_ioctl+0x57/0x79 [74073.217149] [<ffffffff814c5fea>] entry_SYSCALL_64_fastpath+0x18/0xad [74073.218102] [<ffffffff81109552>] ? time_hardirqs_off+0x9/0x14 [74073.218968] [<ffffffff810938ce>] ? trace_hardirqs_off_caller+0x1f/0xaa [74073.219938] INFO: lockdep is turned off. What happened was the following: CPU 1 CPU 2 btrfs_dedupe_file_range() --> using same inode as source and target --> src range is [768K, 1Mb[ --> dst range is [0, 256K[ btrfs_cmp_data_prepare() --> calls gather_extent_pages() for range [768K, 1Mb[ and locks all pages in that range do_writepages() btrfs_writepages() extent_writepages() extent_write_cache_pages() __extent_writepage() writepage_delalloc() find_lock_delalloc_range() --> finds range [0, 1Mb[ lock_delalloc_pages() --> locks all pages in the range [0, 768K[ --> tries to lock page at offset 768K --> deadlock --> calls gather_extent_pages() to lock pages in the range [0, 256K[ --> deadlock, task at CPU 1 already locked that range and it's trying to lock the range we locked previously So fix this by making sure that during a dedup we always lock first the pages from the range with lower offset. Signed-off-by:
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- 17 Feb, 2017 37 commits
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Jeff Mahoney authored
Commit e5d6b12f (Btrfs: don't WARN() in btrfs_transaction_abort() for IO errors) added a pr_debug call to be printed when a transaction is aborted with -EIO instead of WARN. btrfs_debug prints which file system the message is associated with so let's use that instead. Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Jeff Mahoney authored
btrfs_truncate_free_space_cache always allocates a btrfs_path structure but only uses it when the caller passes a block group. Let's move the allocation and free into the conditional. Signed-off-by:
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Jeff Mahoney authored
The free space cache APIs accept a root but always use the tree root. Also, btrfs_truncate_free_space_cache accepts a root AND an inode but the inode always points to the root anyway, so let's just pass the inode. Signed-off-by:
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Jeff Mahoney authored
btrfs_inc_block_group_ro is either passed the extent root or the dev root, but it doesn't do anything with the dev tree. Let's convert to passing an fs_info and using the extent root. Signed-off-by:
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Jeff Mahoney authored
We don't need to pass a root to flush_space since it always uses the fs_root. Signed-off-by:
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Jeff Mahoney authored
Outside of interactions with qgroups, the roots passed in extent-tree.c are usually passed to ensure that we don't do refcounts on log trees or to get the allocation profile for an allocation request. Otherwise, it operates on the extent root. This patch converts some more routines in extent-tree.c that are always called with the extent root to accept an fs_info instead. Signed-off-by:
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Qu Wenruo authored
Just as Filipe pointed out, the most time consuming parts of qgroup are btrfs_qgroup_account_extents() and btrfs_qgroup_prepare_account_extents(). Which both call btrfs_find_all_roots() to get old_roots and new_roots ulist. What makes things worse is, we're calling that expensive btrfs_find_all_roots() at transaction committing time with TRANS_STATE_COMMIT_DOING, which will blocks all incoming transaction. Such behavior is necessary for @new_roots search as current btrfs_find_all_roots() can't do it correctly so we do call it just before switch commit roots. However for @old_roots search, it's not necessary as such search is based on commit_root, so it will always be correct and we can move it out of transaction committing. This patch moves the @old_roots search part out of commit_transaction(), so in theory we can half the time qgroup time consumption at commit_transaction(). But please note that, this won't speedup qgroup overall, the total time consumption is still the same, just reduce the performance stall. Cc: Filipe Manana <fdmanana@suse.com> Signed-off-by:
Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
Both unused after the call to update_cache_item has been moved to __btrfs_wait_cache_io. Reviewed-by:
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David Sterba authored
bitmap_list is unused since the io_ctl framework. Reviewed-by:
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David Sterba authored
Unused since the helper has been split, eb used in the caller. Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
After the page locking has been reworked, we get all pages prepared via cmp_pages. Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
The name parameters have never been used, as the name is passed via the dentry. Reviewed-by:
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David Sterba authored
The 'device' used to be added in that function, but now it's done by the caller. Reviewed-by:
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David Sterba authored
We grab fs_info from other parameters. Reviewed-by:
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David Sterba authored
Never used for anything meaningful since we have our own superblock filler. Reviewed-by:
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David Sterba authored
The 'tree' was used to call locking hook that does not exist anymore. Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
The logic has been updated in "Btrfs: make mapping->writeback_index point to the last written page" (a9132667) and page is not needed anymore. Reviewed-by:
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David Sterba authored
This used to hold number of maximum pages to allocate, but this is now limited by BIO_MAX_PAGES. The local are now unused and removed as well. Reviewed-by:
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David Sterba authored
Not needed. Reviewed-by:
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David Sterba authored
Never needed. Reviewed-by:
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David Sterba authored
None of the checks need to know the ro/rw status as they're all not changing the superblock. Moreover, we can access the sb flags directly if we'd need to decide by the ro/rw status. Reviewed-by:
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David Sterba authored
Added but never used. Reviewed-by:
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David Sterba authored
Unused since qgroup refactoring that split data and metadata accounting, the btrfs_qgroup_free helper. Reviewed-by:
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David Sterba authored
Unused since long ago. Reviewed-by:
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David Sterba authored
Unused since long ago. Reviewed-by:
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David Sterba authored
write_all_supers and write_ctree_super are almost equal, the parameter 'trans' is unused so we can drop it and have just one helper. Reviewed-by:
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David Sterba authored
The barriers are handled by the caller. Reviewed-by:
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David Sterba authored
Never used. Reviewed-by:
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David Sterba authored
Added but never needed. Reviewed-by:
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David Sterba authored
Added but never used. Reviewed-by:
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David Sterba authored
Never used in that function. Reviewed-by:
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David Sterba authored
Change the name so it matches the naming we already use eg. for btrfs_path. Suggested-by:
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