- 27 Feb, 2019 2 commits
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Filipe Manana authored
Reflinking (clone/dedupe) and rename are operations that operate on two inodes and therefore need to lock them in the same order to avoid ABBA deadlocks. It happens that Btrfs' reflink implementation always locked them in a different order from VFS's lock_two_nondirectories() helper, which is used by the rename code in VFS, resulting in ABBA type deadlocks. Btrfs' locking order: static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2) { if (inode1 < inode2) swap(inode1, inode2); inode_lock_nested(inode1, I_MUTEX_PARENT); inode_lock_nested(inode2, I_MUTEX_CHILD); } VFS's locking order: void lock_two_nondirectories(struct inode *inode1, struct inode *inode2) { if (inode1 > inode2) swap(inode1, inode2); if (inode1 && !S_ISDIR(inode1->i_mode)) inode_lock(inode1); if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1) inode_lock_nested(inode2, I_MUTEX_NONDIR2); } Fix this by killing the btrfs helper function that does the double inode locking and replace it with VFS's helper lock_two_nondirectories(). Reported-by:Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Fixes: 416161db ("btrfs: offline dedupe") CC: stable@vger.kernel.org # 4.4+ Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Filipe Manana authored
In the past we had data corruption when reading compressed extents that are shared within the same file and they are consecutive, this got fixed by commit 005efedf ("Btrfs: fix read corruption of compressed and shared extents") and by commit 808f80b4 ("Btrfs: update fix for read corruption of compressed and shared extents"). However there was a case that was missing in those fixes, which is when the shared and compressed extents are referenced with a non-zero offset. The following shell script creates a reproducer for this issue: #!/bin/bash mkfs.btrfs -f /dev/sdc &> /dev/null mount -o compress /dev/sdc /mnt/sdc # Create a file with 3 consecutive compressed extents, each has an # uncompressed size of 128Kb and a compressed size of 4Kb. for ((i = 1; i <= 3; i++)); do head -c 4096 /dev/zero for ((j = 1; j <= 31; j++)); do head -c 4096 /dev/zero | tr '\0' "\377" done done > /mnt/sdc/foobar sync echo "Digest after file creation: $(md5sum /mnt/sdc/foobar)" # Clone the first extent into offsets 128K and 256K. xfs_io -c "reflink /mnt/sdc/foobar 0 128K 128K" /mnt/sdc/foobar xfs_io -c "reflink /mnt/sdc/foobar 0 256K 128K" /mnt/sdc/foobar sync echo "Digest after cloning: $(md5sum /mnt/sdc/foobar)" # Punch holes into the regions that are already full of zeroes. xfs_io -c "fpunch 0 4K" /mnt/sdc/foobar xfs_io -c "fpunch 128K 4K" /mnt/sdc/foobar xfs_io -c "fpunch 256K 4K" /mnt/sdc/foobar sync echo "Digest after hole punching: $(md5sum /mnt/sdc/foobar)" echo "Dropping page cache..." sysctl -q vm.drop_caches=1 echo "Digest after hole punching: $(md5sum /mnt/sdc/foobar)" umount /dev/sdc When running the script we get the following output: Digest after file creation: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar linked 131072/131072 bytes at offset 131072 128 KiB, 1 ops; 0.0033 sec (36.960 MiB/sec and 295.6830 ops/sec) linked 131072/131072 bytes at offset 262144 128 KiB, 1 ops; 0.0015 sec (78.567 MiB/sec and 628.5355 ops/sec) Digest after cloning: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar Digest after hole punching: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar Dropping page cache... Digest after hole punching: fba694ae8664ed0c2e9ff8937e7f1484 /mnt/sdc/foobar This happens because after reading all the pages of the extent in the range from 128K to 256K for example, we read the hole at offset 256K and then when reading the page at offset 260K we don't submit the existing bio, which is responsible for filling all the page in the range 128K to 256K only, therefore adding the pages from range 260K to 384K to the existing bio and submitting it after iterating over the entire range. Once the bio completes, the uncompressed data fills only the pages in the range 128K to 256K because there's no more data read from disk, leaving the pages in the range 260K to 384K unfilled. It is just a slightly different variant of what was solved by commit 005efedf ("Btrfs: fix read corruption of compressed and shared extents"). Fix this by forcing a bio submit, during readpages(), whenever we find a compressed extent map for a page that is different from the extent map for the previous page or has a different starting offset (in case it's the same compressed extent), instead of the extent map's original start offset. A test case for fstests follows soon. Reported-by:
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- 25 Feb, 2019 38 commits
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YueHaibing authored
There is a messy cast here: min_t(int, len, (int)sizeof(*item))); min_t() should normally cast to unsigned. It's not possible for "len" to be negative, but if it were then we definitely wouldn't want to pass negatives to read_extent_buffer(). Also there is an extra cast. This patch shouldn't affect runtime, it's just a clean up. Reviewed-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
YueHaibing <yuehaibing@huawei.com> Signed-off-by:
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Filipe Manana authored
At ctree.c:key_search(), the assertion that verifies the first key on a child extent buffer corresponds to the key at a specific slot in the parent has a disadvantage: we effectively hit a BUG_ON() which requires rebooting the machine later. It also does not tell any information about which extent buffer is affected, from which root, the expected and found keys, etc. However as of commit 581c1760 ("btrfs: Validate child tree block's level and first key"), that assertion is not needed since at the time we read an extent buffer from disk we validate that its first key matches the key, at the respective slot, in the parent extent buffer. Therefore just remove the assertion at key_search(). Reviewed-by:
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Filipe Manana authored
The function map_private_extent_buffer() can return an -EINVAL error, and it is called by generic_bin_search() which will return back the error. The btrfs_bin_search() function in turn calls generic_bin_search() and the key_search() function calls btrfs_bin_search(), so both can return the -EINVAL error coming from the map_private_extent_buffer() function. Some callers of these functions were ignoring that these functions can return an error, so fix them to deal with error return values. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
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Dan Carpenter authored
We should drop the lock on this error path. This has been found by a static tool. The lock needs to be released, it's there to protect access to the dev_replace members and is not supposed to be left locked. The value of state that's being switched would need to be artifically changed to an invalid value so the default: branch is taken. Fixes: d189dd70 ("btrfs: fix use-after-free due to race between replace start and cancel") CC: stable@vger.kernel.org # 5.0+ Reviewed-by:
Anand Jain <anand.jain@oracle.com> Signed-off-by:
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Johannes Thumshirn authored
We recently had a customer issue with a corrupted filesystem. When trying to mount this image btrfs panicked with a division by zero in calc_stripe_length(). The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length() takes this value and divides it by the number of copies the RAID profile is expected to have to calculate the amount of data stripes. As a DUP profile is expected to have 2 copies this division resulted in 1/2 = 0. Later then the 'data_stripes' variable is used as a divisor in the stripe length calculation which results in a division by 0 and thus a kernel panic. When encountering a filesystem with a DUP block group and a 'num_stripes' value unequal to 2, refuse mounting as the image is corrupted and will lead to unexpected behaviour. Code inspection showed a RAID1 block group has the same issues. Fixes: e06cd3dd ("Btrfs: add validadtion checks for chunk loading") CC: stable@vger.kernel.org # 4.4+ Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by:
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Dan Robertson authored
The scrub_ctx csum_list member must be initialized before scrub_free_ctx is called. If the csum_list is not initialized beforehand, the list_empty call in scrub_free_csums will result in a null deref if the allocation fails in the for loop. Fixes: a2de733c ("btrfs: scrub") CC: stable@vger.kernel.org # 3.0+ Reviewed-by:
Dan Robertson <dan@dlrobertson.com> Reviewed-by:
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Filipe Manana authored
Comparing the content of the pages in the range to deduplicate is now done in generic_remap_checks called by the generic helper generic_remap_file_range_prep(), which takes care of ensuring we do not compare/deduplicate undefined data beyond a file's EOF (range from EOF to the next block boundary). So remove these checks which are now redundant. Reviewed-by:
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Filipe Manana authored
After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by:
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Filipe Manana authored
After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by:
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Josef Bacik authored
Qgroups will do the old roots lookup at delayed ref time, which could be while walking down the extent root while running a delayed ref. This should be fine, except we specifically lock eb's in the backref walking code irrespective of path->skip_locking, which deadlocks the system. Fix up the backref code to honor path->skip_locking, nobody will be modifying the commit_root when we're searching so it's completely safe to do. This happens since fb235dc0 ("btrfs: qgroup: Move half of the qgroup accounting time out of commit trans"), kernel may lockup with quota enabled. There is one backref trace triggered by snapshot dropping along with write operation in the source subvolume. The example can be reliably reproduced: btrfs-cleaner D 0 4062 2 0x80000000 Call Trace: schedule+0x32/0x90 btrfs_tree_read_lock+0x93/0x130 [btrfs] find_parent_nodes+0x29b/0x1170 [btrfs] btrfs_find_all_roots_safe+0xa8/0x120 [btrfs] btrfs_find_all_roots+0x57/0x70 [btrfs] btrfs_qgroup_trace_extent_post+0x37/0x70 [btrfs] btrfs_qgroup_trace_leaf_items+0x10b/0x140 [btrfs] btrfs_qgroup_trace_subtree+0xc8/0xe0 [btrfs] do_walk_down+0x541/0x5e3 [btrfs] walk_down_tree+0xab/0xe7 [btrfs] btrfs_drop_snapshot+0x356/0x71a [btrfs] btrfs_clean_one_deleted_snapshot+0xb8/0xf0 [btrfs] cleaner_kthread+0x12b/0x160 [btrfs] kthread+0x112/0x130 ret_from_fork+0x27/0x50 When dropping snapshots with qgroup enabled, we will trigger backref walk. However such backref walk at that timing is pretty dangerous, as if one of the parent nodes get WRITE locked by other thread, we could cause a dead lock. For example: FS 260 FS 261 (Dropped) node A node B / \ / \ node C node D node E / \ / \ / \ leaf F|leaf G|leaf H|leaf I|leaf J|leaf K The lock sequence would be: Thread A (cleaner) | Thread B (other writer) ----------------------------------------------------------------------- write_lock(B) | write_lock(D) | ^^^ called by walk_down_tree() | | write_lock(A) | write_lock(D) << Stall read_lock(H) << for backref walk | read_lock(D) << lock owner is | the same thread A | so read lock is OK | read_lock(A) << Stall | So thread A hold write lock D, and needs read lock A to unlock. While thread B holds write lock A, while needs lock D to unlock. This will cause a deadlock. This is not only limited to snapshot dropping case. As the backref walk, even only happens on commit trees, is breaking the normal top-down locking order, makes it deadlock prone. Fixes: fb235dc0 ("btrfs: qgroup: Move half of the qgroup accounting time out of commit trans") CC: stable@vger.kernel.org # 4.14+ Reported-and-tested-by:
Josef Bacik <josef@toxicpanda.com> Reviewed-by:
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Qu Wenruo authored
[BUG] Btrfs qgroup will still hit EDQUOT under the following case: $ dev=/dev/test/test $ mnt=/mnt/btrfs $ umount $mnt &> /dev/null $ umount $dev &> /dev/null $ mkfs.btrfs -f $dev $ mount $dev $mnt -o nospace_cache $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ fallocate -l 900M $mnt/subv/padding $ sync $ rm $mnt/subv/padding # Hit EDQUOT $ xfs_io -f -c "pwrite 0 512M" $mnt/subv/real_file [CAUSE] Since commit a514d638 ("btrfs: qgroup: Commit transaction in advance to reduce early EDQUOT"), btrfs is not forced to commit transaction to reclaim more quota space. Instead, we just check pertrans metadata reservation against some threshold and try to do asynchronously transaction commit. However in above case, the pertrans metadata reservation is pretty small thus it will never trigger asynchronous transaction commit. [FIX] Instead of only accounting pertrans metadata reservation, we calculate how much free space we have, and if there isn't much free space left, commit transaction asynchronously to try to free some space. This may slow down the fs when we have less than 32M free qgroup space, but should reduce a lot of false EDQUOT, so the cost should be acceptable. Signed-off-by:
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Qu Wenruo authored
btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record [BUG] Btrfs/139 will fail with a high probability if the testing machine (VM) has only 2G RAM. Resulting the final write success while it should fail due to EDQUOT, and the fs will have quota exceeding the limit by 16K. The simplified reproducer will be: (needs a 2G ram VM) $ mkfs.btrfs -f $dev $ mount $dev $mnt $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ for i in $(seq -w 1 8); do xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null echo "file $i written" > /dev/kmsg done $ sync $ btrfs qgroup show -pcre --raw $mnt The last pwrite will not trigger EDQUOT and final 'qgroup show' will show something like: qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16384 16384 none none --- --- 0/256 1073758208 1073758208 none 1073741824 --- --- And 1073758208 is larger than > 1073741824. [CAUSE] It's a bug in btrfs qgroup data reserved space management. For quota limit, we must ensure that: reserved (data + metadata) + rfer/excl <= limit Since rfer/excl is only updated at transaction commmit time, reserved space needs to be taken special care. One important part of reserved space is data, and for a new data extent written to disk, we still need to take the reserved space until rfer/excl numbers get updated. Originally when an ordered extent finishes, we migrate the reserved qgroup data space from extent_io tree to delayed ref head of the data extent, expecting delayed ref will only be cleaned up at commit transaction time. However for small RAM machine, due to memory pressure dirty pages can be flushed back to disk without committing a transaction. The related events will be something like: file 1 written btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840 btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096 btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344 btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192 btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344 cleanup_ref_head: num_bytes=54947840 cleanup_ref_head: num_bytes=5636096 cleanup_ref_head: num_bytes=569344 cleanup_ref_head: num_bytes=57344 cleanup_ref_head: num_bytes=8192 ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space file 2 written ... file 8 written cleanup_ref_head: num_bytes=8192 ... btrfs_commit_transaction <<< the only transaction committed during the test When file 2 is written, we have already freed 128M reserved qgroup data space for ino 258. Thus later write won't trigger EDQUOT. This allows us to write more data beyond qgroup limit. In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT. [FIX] By moving reserved qgroup data space from btrfs_delayed_ref_head to btrfs_qgroup_extent_record, we can ensure that reserved qgroup data space won't be freed half way before commit transaction, thus fix the problem. Fixes: f64d5ca8 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref") Signed-off-by: -
David Sterba authored
The member btrfs_fs_info::scrub_nocow_workers is unused since the nocow optimization was removed from scrub in 9bebe665 ("btrfs: scrub: Remove unused copy_nocow_pages and its callchain"). Reviewed-by:
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David Sterba authored
The scrub worker pointers are not NULL iff the scrub is running, so reset them back once the last reference is dropped. Add assertions to the initial phase of scrub to verify that. Reviewed-by:
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Anand Jain authored
Use the refcount_t for fs_info::scrub_workers_refcnt instead of int so we get the extra checks. All reference changes are still done under scrub_lock. Signed-off-by:
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Anand Jain authored
scrub_workers_refcnt is protected by scrub_lock, add lockdep_assert_held() in scrub_workers_get(). Signed-off-by:
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Anand Jain authored
This fixes a longstanding lockdep warning triggered by fstests/btrfs/011. Circular locking dependency check reports warning[1], that's because the btrfs_scrub_dev() calls the stack #0 below with, the fs_info::scrub_lock held. The test case leading to this warning: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /btrfs $ btrfs scrub start -B /btrfs In fact we have fs_info::scrub_workers_refcnt to track if the init and destroy of the scrub workers are needed. So once we have incremented and decremented the fs_info::scrub_workers_refcnt value in the thread, its ok to drop the scrub_lock, and then actually do the btrfs_destroy_workqueue() part. So this patch drops the scrub_lock before calling btrfs_destroy_workqueue(). [359.258534] ====================================================== [359.260305] WARNING: possible circular locking dependency detected [359.261938] 5.0.0-rc6-default #461 Not tainted [359.263135] ------------------------------------------------------ [359.264672] btrfs/20975 is trying to acquire lock: [359.265927] 00000000d4d32bea ((wq_completion)"%s-%s""btrfs", name){+.+.}, at: flush_workqueue+0x87/0x540 [359.268416] [359.268416] but task is already holding lock: [359.270061] 0000000053ea26a6 (&fs_info->scrub_lock){+.+.}, at: btrfs_scrub_dev+0x322/0x590 [btrfs] [359.272418] [359.272418] which lock already depends on the new lock. [359.272418] [359.274692] [359.274692] the existing dependency chain (in reverse order) is: [359.276671] [359.276671] -> #3 (&fs_info->scrub_lock){+.+.}: [359.278187] __mutex_lock+0x86/0x9c0 [359.279086] btrfs_scrub_pause+0x31/0x100 [btrfs] [359.280421] btrfs_commit_transaction+0x1e4/0x9e0 [btrfs] [359.281931] close_ctree+0x30b/0x350 [btrfs] [359.283208] generic_shutdown_super+0x64/0x100 [359.284516] kill_anon_super+0x14/0x30 [359.285658] btrfs_kill_super+0x12/0xa0 [btrfs] [359.286964] deactivate_locked_super+0x29/0x60 [359.288242] cleanup_mnt+0x3b/0x70 [359.289310] task_work_run+0x98/0xc0 [359.290428] exit_to_usermode_loop+0x83/0x90 [359.291445] do_syscall_64+0x15b/0x180 [359.292598] entry_SYSCALL_64_after_hwframe+0x49/0xbe [359.294011] [359.294011] -> #2 (sb_internal#2){.+.+}: [359.295432] __sb_start_write+0x113/0x1d0 [359.296394] start_transaction+0x369/0x500 [btrfs] [359.297471] btrfs_finish_ordered_io+0x2aa/0x7c0 [btrfs] [359.298629] normal_work_helper+0xcd/0x530 [btrfs] [359.299698] process_one_work+0x246/0x610 [359.300898] worker_thread+0x3c/0x390 [359.302020] kthread+0x116/0x130 [359.303053] ret_from_fork+0x24/0x30 [359.304152] [359.304152] -> #1 ((work_completion)(&work->normal_work)){+.+.}: [359.306100] process_one_work+0x21f/0x610 [359.307302] worker_thread+0x3c/0x390 [359.308465] kthread+0x116/0x130 [359.309357] ret_from_fork+0x24/0x30 [359.310229] [359.310229] -> #0 ((wq_completion)"%s-%s""btrfs", name){+.+.}: [359.311812] lock_acquire+0x90/0x180 [359.312929] flush_workqueue+0xaa/0x540 [359.313845] drain_workqueue+0xa1/0x180 [359.314761] destroy_workqueue+0x17/0x240 [359.315754] btrfs_destroy_workqueue+0x57/0x200 [btrfs] [359.317245] scrub_workers_put+0x2c/0x60 [btrfs] [359.318585] btrfs_scrub_dev+0x336/0x590 [btrfs] [359.319944] btrfs_dev_replace_by_ioctl.cold.19+0x179/0x1bb [btrfs] [359.321622] btrfs_ioctl+0x28a4/0x2e40 [btrfs] [359.322908] do_vfs_ioctl+0xa2/0x6d0 [359.324021] ksys_ioctl+0x3a/0x70 [359.325066] __x64_sys_ioctl+0x16/0x20 [359.326236] do_syscall_64+0x54/0x180 [359.327379] entry_SYSCALL_64_after_hwframe+0x49/0xbe [359.328772] [359.328772] other info that might help us debug this: [359.328772] [359.330990] Chain exists of: [359.330990] (wq_completion)"%s-%s""btrfs", name --> sb_internal#2 --> &fs_info->scrub_lock [359.330990] [359.334376] Possible unsafe locking scenario: [359.334376] [359.336020] CPU0 CPU1 [359.337070] ---- ---- [359.337821] lock(&fs_info->scrub_lock); [359.338506] lock(sb_internal#2); [359.339506] lock(&fs_info->scrub_lock); [359.341461] lock((wq_completion)"%s-%s""btrfs", name); [359.342437] [359.342437] *** DEADLOCK *** [359.342437] [359.343745] 1 lock held by btrfs/20975: [359.344788] #0: 0000000053ea26a6 (&fs_info->scrub_lock){+.+.}, at: btrfs_scrub_dev+0x322/0x590 [btrfs] [359.346778] [359.346778] stack backtrace: [359.347897] CPU: 0 PID: 20975 Comm: btrfs Not tainted 5.0.0-rc6-default #461 [359.348983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [359.350501] Call Trace: [359.350931] dump_stack+0x67/0x90 [359.351676] print_circular_bug.isra.37.cold.56+0x15c/0x195 [359.353569] check_prev_add.constprop.44+0x4f9/0x750 [359.354849] ? check_prev_add.constprop.44+0x286/0x750 [359.356505] __lock_acquire+0xb84/0xf10 [359.357505] lock_acquire+0x90/0x180 [359.358271] ? flush_workqueue+0x87/0x540 [359.359098] flush_workqueue+0xaa/0x540 [359.359912] ? flush_workqueue+0x87/0x540 [359.360740] ? drain_workqueue+0x1e/0x180 [359.361565] ? drain_workqueue+0xa1/0x180 [359.362391] drain_workqueue+0xa1/0x180 [359.363193] destroy_workqueue+0x17/0x240 [359.364539] btrfs_destroy_workqueue+0x57/0x200 [btrfs] [359.365673] scrub_workers_put+0x2c/0x60 [btrfs] [359.366618] btrfs_scrub_dev+0x336/0x590 [btrfs] [359.367594] ? start_transaction+0xa1/0x500 [btrfs] [359.368679] btrfs_dev_replace_by_ioctl.cold.19+0x179/0x1bb [btrfs] [359.369545] btrfs_ioctl+0x28a4/0x2e40 [btrfs] [359.370186] ? __lock_acquire+0x263/0xf10 [359.370777] ? kvm_clock_read+0x14/0x30 [359.371392] ? kvm_sched_clock_read+0x5/0x10 [359.372248] ? sched_clock+0x5/0x10 [359.372786] ? sched_clock_cpu+0xc/0xc0 [359.373662] ? do_vfs_ioctl+0xa2/0x6d0 [359.374552] do_vfs_ioctl+0xa2/0x6d0 [359.375378] ? do_sigaction+0xff/0x250 [359.376233] ksys_ioctl+0x3a/0x70 [359.376954] __x64_sys_ioctl+0x16/0x20 [359.377772] do_syscall_64+0x54/0x180 [359.378841] entry_SYSCALL_64_after_hwframe+0x49/0xbe [359.380422] RIP: 0033:0x7f5429296a97 Backporting to older kernels: scrub_nocow_workers must be freed the same way as the others. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: -
Anand Jain authored
We have killed volume mutex (commit: dccdb07b btrfs: kill btrfs_fs_info::volume_mutex). This a trival one seems to have escaped. Signed-off-by:
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Qu Wenruo authored
There is no need to forward declare flush_write_bio(), as it only depends on submit_one_bio(). Both of them are pretty small, just move them to kill the forward declaration. Reviewed-by:
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Nikolay Borisov authored
The variables and function parameters of __etree_search which pertain to prev/next are grossly misnamed. Namely, prev_ret holds the next state and not the previous. Similarly, next_ret actually holds the previous extent state relating to the offset we are interested in. Fix this by renaming the variables as well as switching the arguments order. No functional changes. Signed-off-by:
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Nikolay Borisov authored
With the refactoring introduced in 8b62f87b ("Btrfs: reworki outstanding_extents") this flag became unused. Remove it and renumber the following flags accordingly. No functional changes. Reviewed-by:
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Nikolay Borisov authored
There is no point in using a construct like 'if (!condition) WARN_ON(1)'. Use WARN_ON(!condition) directly. No functional changes. Reviewed-by:
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Josef Bacik authored
We could generate a lot of delayed refs in evict but never have any left over space from our block rsv to make up for that fact. So reserve some extra space and give it to the transaction so it can be used to refill the delayed refs rsv every loop through the truncate path. Signed-off-by:
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Josef Bacik authored
For FLUSH_LIMIT flushers we really can only allocate chunks and flush delayed inode items, everything else is problematic. I added a bunch of new states and it lead to weirdness in the FLUSH_LIMIT case because I forgot about how it worked. So instead explicitly declare the states that are ok for flushing with FLUSH_LIMIT and use that for our state machine. Then as we add new things that are safe we can just add them to this list. Reviewed-by:
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Josef Bacik authored
With severe fragmentation we can end up with our inode rsv size being huge during writeout, which would cause us to need to make very large metadata reservations. However we may not actually need that much once writeout is complete, because of the over-reservation for the worst case. So instead try to make our reservation, and if we couldn't make it re-calculate our new reservation size and try again. If our reservation size doesn't change between tries then we know we are actually out of space and can error. Flushing that could have been running in parallel did not make any space. Signed-off-by:
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Josef Bacik authored
With the introduction of the per-inode block_rsv it became possible to have really really large reservation requests made because of data fragmentation. Since the ticket stuff assumed that we'd always have relatively small reservation requests it just killed all tickets if we were unable to satisfy the current request. However, this is generally not the case anymore. So fix this logic to instead see if we had a ticket that we were able to give some reservation to, and if we were continue the flushing loop again. Likewise we make the tickets use the space_info_add_old_bytes() method of returning what reservation they did receive in hopes that it could satisfy reservations down the line. Reviewed-by:
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Josef Bacik authored
We've done this forever because of the voodoo around knowing how much space we have. However, we have better ways of doing this now, and on normal file systems we'll easily have a global reserve of 512MiB, and since metadata chunks are usually 1GiB that means we'll allocate metadata chunks more readily. Instead use the actual used amount when determining if we need to allocate a chunk or not. This has a side effect for mixed block group fs'es where we are no longer allocating enough chunks for the data/metadata requirements. To deal with this add a ALLOC_CHUNK_FORCE step to the flushing state machine. This will only get used if we've already made a full loop through the flushing machinery and tried committing the transaction. If we have then we can try and force a chunk allocation since we likely need it to make progress. This resolves issues I was seeing with the mixed bg tests in xfstests without the new flushing state. Reviewed-by:
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Josef Bacik authored
For enospc_debug having the block rsvs is super helpful to see if we've done something wrong. Reviewed-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
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Josef Bacik authored
may_commit_transaction will skip committing the transaction if we don't have enough pinned space or if we're trying to find space for a SYSTEM chunk. However, if we have pending free block groups in this transaction we still want to commit as we may be able to allocate a chunk to make our reservation. So instead of just returning ENOSPC, check if we have free block groups pending, and if so commit the transaction to allow us to use that free space. Reviewed-by:
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Dennis Zhou authored
Zstd compression requires different amounts of memory for each level of compression. The prior patches implemented indirection to allow for each compression type to manage their workspaces independently. This patch uses this indirection to implement compression level support for zstd. To manage the additional memory require, each compression level has its own queue of workspaces. A global LRU is used to help with reclaim. Reclaim is done via a timer which provides a mechanism to decrease memory utilization by keeping only workspaces around that are sized appropriately. Forward progress is guaranteed by a preallocated max workspace hidden from the LRU. When getting a workspace, it uses a bitmap to identify the levels that are populated and scans up. If it finds a workspace that is greater than it, it uses it, but does not update the last_used time and the corresponding place in the LRU. If we hit memory pressure, we sleep on the max level workspace. We continue to rescan in case we can use a smaller workspace, but eventually should be able to obtain the max level workspace or allocate one again should memory pressure subside. The memory requirement for decompression is the same as level 1, and therefore can use any of available workspace. The number of workspaces is bound by an upper limit of the workqueue's limit which currently is 2 (percpu limit). The reclaim timer is used to free inactive/improperly sized workspaces and is set to 307s to avoid colliding with transaction commit (every 30s). Repeating the experiment from v2 [1], the Silesia corpus was copied to a btrfs filesystem 10 times and then read back after dropping the caches. The btrfs filesystem was on an SSD. Level Ratio Compression (MB/s) Decompression (MB/s) Memory (KB) 1 2.658 438.47 910.51 780 2 2.744 364.86 886.55 1004 3 2.801 336.33 828.41 1260 4 2.858 286.71 886.55 1260 5 2.916 212.77 556.84 1388 6 2.363 119.82 990.85 1516 7 3.000 154.06 849.30 1516 8 3.011 159.54 875.03 1772 9 3.025 100.51 940.15 1772 10 3.033 118.97 616.26 1772 11 3.036 94.19 802.11 1772 12 3.037 73.45 931.49 1772 13 3.041 55.17 835.26 2284 14 3.087 44.70 716.78 2547 15 3.126 37.30 878.84 2547 [1] https://lore.kernel.org/linux-btrfs/20181031181108.289340-1-terrelln@fb.com/ Cc: Nick Terrell <terrelln@fb.com> Cc: Omar Sandoval <osandov@osandov.com> Signed-off-by:
Dennis Zhou <dennis@kernel.org> Reviewed-by:
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Dennis Zhou authored
It is possible based on the level configurations that a higher level workspace uses less memory than a lower level workspace. In order to reuse workspaces, this must be made a monotonic relationship. This precomputes the required memory for each level and enforces the monotonicity between level and memory required. This is also done in upstream zstd in [1]. [1] https://github.com/facebook/zstd/commit/a68b76afefec6876f8e8a538155109a5aeac0143 Cc: Nick Terrell <terrelln@fb.com> Signed-off-by:
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Dennis Zhou authored
Zstd currently only supports the default level of compression. This patch switches to using the level passed in for btrfs zstd configuration. Zstd workspaces now keep track of the requested level as this can differ from the size of the workspace. Reviewed-by:
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Dennis Zhou authored
Currently, the only user of set_level() is zlib which sets an internal workspace parameter. As level is now plumbed into get_workspace(), this can be handled there rather than separately. This repurposes set_level() to bound the level passed in so it can be used when setting the mounts compression level and as well as verifying the level before getting a workspace. The other benefit is this divides the meaning of compress(0) and get_workspace(0). The former means we want to use the default compression level of the compression type. The latter means we can use any workspace available. Signed-off-by:
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Dennis Zhou authored
Zlib compression supports multiple levels, but doesn't require changing in how a workspace itself is created and managed. Zstd introduces a different memory requirement such that higher levels of compression require more memory. This requires changes in how the alloc()/get() methods work for zstd. This pach plumbs compression level through the interface as a parameter in preparation for zstd compression levels. This gives the compression types opportunity to create/manage based on the compression level. Reviewed-by:
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Dennis Zhou authored
The previous patch added generic helpers for get_workspace() and put_workspace(). Now, we can migrate ownership of the workspace_manager to be in the compression type code as the compression code itself doesn't care beyond being able to get a workspace. The init/cleanup and get/put methods are abstracted so each compression algorithm can decide how they want to manage their workspaces. Reviewed-by:
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Dennis Zhou authored
There are two levels of workspace management. First, alloc()/free() which are responsible for actually creating and destroy workspaces. Second, at a higher level, get()/put() which is the compression code asking for a workspace from a workspace_manager. The compression code shouldn't really care how it gets a workspace, but that it got a workspace. This adds get_workspace() and put_workspace() to be the higher level interface which is responsible for indexing into the appropriate compression type. It also introduces btrfs_put_workspace() and btrfs_get_workspace() to be the generic implementations of the higher interface. Reviewed-by:
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Dennis Zhou authored
Workspace manager init and cleanup code is open coded inside a for loop over the compression types. This forces each compression type to rely on the same workspace manager implementation. This patch creates helper methods that will be the generic implementation for btrfs workspace management. Reviewed-by:
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Dennis Zhou authored
Make the workspace_manager own the interface operations rather than managing index-paired arrays for the workspace_manager and compression operations. Reviewed-by:
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