Filipe Manana 6b0a4f603d btrfs: fix race when defragmenting leads to unnecessary IO ... [ Upstream commit 7f458a3873 ] When defragmenting we skip ranges that have holes or inline extents, so that we don't do unnecessary IO and waste space. We do this check when calling should_defrag_range() at btrfs_defrag_file(). However we do it without holding the inode's lock. The reason we do it like this is to avoid blocking other tasks for too long, that possibly want to operate on other file ranges, since after the call to should_defrag_range() and before locking the inode, we trigger a synchronous page cache readahead. However before we were able to lock the inode, some other task might have punched a hole in our range, or we may now have an inline extent there, in which case we should not set the range for defrag anymore since that would cause unnecessary IO and make us waste space (i.e. allocating extents to contain zeros for a hole). So after we locked the inode and the range in the iotree, check again if we have holes or an inline extent, and if we do, just skip the range. I hit this while testing my next patch that fixes races when updating an inode's number of bytes (subject "btrfs: update the number of bytes used by an inode atomically"), and it depends on this change in order to work correctly. Alternatively I could rework that other patch to detect holes and flag their range with the 'new delalloc' bit, but this itself fixes an efficiency problem due a race that from a functional point of view is not harmful (it could be triggered with btrfs/062 from fstests). CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-01-06 14:48:36 +01:00
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tests	btrfs: Correctly handle empty trees in find_first_clear_extent_bit	2020-02-11 04:35:34 -08:00
Kconfig	btrfs: Fix build error while LIBCRC32C is module	2019-07-17 17:03:30 +02:00
Makefile	btrfs: migrate the block group lookup code	2019-09-09 14:59:04 +02:00
acl.c	btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter	2019-04-29 19:02:44 +02:00
async-thread.c	Btrfs: fix crash during unmount due to race with delayed inode workers	2020-04-17 10:50:15 +02:00
async-thread.h	Btrfs: fix crash during unmount due to race with delayed inode workers	2020-04-17 10:50:15 +02:00
backref.c	btrfs: fix double free on ulist after backref resolution failure	2020-07-29 10:18:30 +02:00
backref.h	btrfs: fiemap: preallocate ulists for btrfs_check_shared	2019-07-01 13:34:53 +02:00
block-group.c	btrfs: take overcommit into account in inc_block_group_ro	2020-10-17 10:11:21 +02:00
block-group.h	btrfs: move struct io_ctl to free-space-cache.h	2019-09-09 14:59:15 +02:00
block-rsv.c	btrfs: force chunk allocation if our global rsv is larger than metadata	2020-06-22 09:31:13 +02:00
block-rsv.h	btrfs: migrate the global_block_rsv helpers to block-rsv.c	2019-07-02 12:30:55 +02:00
btrfs_inode.h	btrfs: remove assumption about csum type form btrfs_print_data_csum_error()	2019-07-01 13:35:02 +02:00
check-integrity.c	btrfs: fix possible NULL-pointer dereference in integrity checks	2020-02-24 08:36:53 +01:00
check-integrity.h	btrfs: replace GPL boilerplate by SPDX -- headers	2018-04-12 16:29:46 +02:00
compression.c	btrfs: move cond_wake_up functions out of ctree	2019-09-09 14:59:15 +02:00
compression.h	btrfs: compression: replace set_level callbacks by a common helper	2019-09-09 14:59:11 +02:00
ctree.c	btrfs: cleanup cow block on error	2020-11-05 11:43:27 +01:00
ctree.h	btrfs: fix readahead hang and use-after-free after removing a device	2020-11-05 11:43:27 +01:00
delalloc-space.c	Btrfs: fix qgroup double free after failure to reserve metadata for delalloc	2019-10-17 20:13:44 +02:00
delalloc-space.h	btrfs: migrate the delalloc space stuff to it's own home	2019-07-04 17:26:17 +02:00
delayed-inode.c	btrfs: qgroup: fix wrong qgroup metadata reserve for delayed inode	2020-11-05 11:43:26 +01:00
delayed-inode.h	Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root	2018-10-15 17:23:33 +02:00
delayed-ref.c	Btrfs: fix race between adding and putting tree mod seq elements and nodes	2020-02-11 04:35:34 -08:00
delayed-ref.h	btrfs: migrate the delayed refs rsv code	2019-07-04 17:26:17 +02:00
dev-replace.c	btrfs: dev-replace: fail mount if we don't have replace item with target device	2020-11-18 19:20:29 +01:00
dev-replace.h	btrfs: get fs_info from trans in btrfs_run_dev_replace	2019-04-29 19:02:43 +02:00
dir-item.c	btrfs: remove unused parameter fs_info from btrfs_extend_item	2019-04-29 19:02:50 +02:00
disk-io.c	btrfs: fix overflow when copying corrupt csums for a message	2020-10-01 13:18:24 +02:00
disk-io.h	btrfs: Make reada_tree_block_flagged private	2019-09-09 14:59:11 +02:00
export.c	btrfs: export helpers for subvolume name/id resolution	2020-08-26 10:40:49 +02:00
export.h	btrfs: export helpers for subvolume name/id resolution	2020-08-26 10:40:49 +02:00
extent-tree.c	btrfs: trim: fix underflow in trim length to prevent access beyond device boundary	2020-12-30 11:51:37 +01:00
extent_io.c	btrfs: fix potential deadlock in the search ioctl	2020-09-09 19:12:31 +02:00
extent_io.h	btrfs: trim: fix underflow in trim length to prevent access beyond device boundary	2020-12-30 11:51:37 +01:00
extent_map.c	Btrfs: fix race between using extent maps and merging them	2020-02-19 19:53:00 +01:00
extent_map.h	btrfs: Remove impossible condition from mergable_maps	2019-02-25 14:13:21 +01:00
file-item.c	btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums	2020-06-22 09:30:55 +02:00
file.c	btrfs: allow btrfs_truncate_block() to fallback to nocow for data space reservation	2020-10-14 10:33:00 +02:00
free-space-cache.c	btrfs: fix space cache memory leak after transaction abort	2020-09-03 11:27:02 +02:00
free-space-cache.h	btrfs: move struct io_ctl to free-space-cache.h	2019-09-09 14:59:15 +02:00
free-space-tree.c	btrfs: move basic block_group definitions to their own header	2019-09-09 14:59:03 +02:00
free-space-tree.h	btrfs: move basic block_group definitions to their own header	2019-09-09 14:59:03 +02:00
inode-item.c	btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref	2019-09-09 14:59:16 +02:00
inode-map.c	btrfs: qgroup: Always free PREALLOC META reserve in btrfs_delalloc_release_extents()	2019-10-15 18:50:07 +02:00
inode-map.h	btrfs: replace GPL boilerplate by SPDX -- headers	2018-04-12 16:29:46 +02:00
inode.c	btrfs: allow btrfs_truncate_block() to fallback to nocow for data space reservation	2020-10-14 10:33:00 +02:00
ioctl.c	btrfs: fix race when defragmenting leads to unnecessary IO	2021-01-06 14:48:36 +01:00
locking.c	btrfs: move cond_wake_up functions out of ctree	2019-09-09 14:59:15 +02:00
locking.h	btrfs: Remove unused locking functions	2019-09-09 14:58:59 +02:00
lzo.c	btrfs: compression: replace set_level callbacks by a common helper	2019-09-09 14:59:11 +02:00
misc.h	btrfs: move math functions to misc.h	2019-09-09 14:59:15 +02:00
ordered-data.c	Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents	2020-02-28 17:22:24 +01:00
ordered-data.h	btrfs: don't assume ordered sums to be 4 bytes	2019-07-01 13:35:00 +02:00
orphan.c	btrfs: replace GPL boilerplate by SPDX -- sources	2018-04-12 16:29:51 +02:00
print-tree.c	btrfs: require only sector size alignment for parent eb bytenr	2020-09-17 13:47:51 +02:00
print-tree.h	btrfs: print-tree: debugging output enhancement	2018-04-20 19:18:16 +02:00
props.c	btrfs: rename the btrfs_calc_*_metadata_size helpers	2019-09-09 14:59:13 +02:00
props.h	btrfs: delete unused function btrfs_set_prop_trans	2019-04-29 19:02:54 +02:00
qgroup.c	btrfs: fix lockdep splat when reading qgroup config on mount	2020-12-02 08:49:45 +01:00
qgroup.h	btrfs: make btrfs_qgroup_check_reserved_leak take btrfs_inode	2020-09-03 11:26:47 +02:00
raid56.c	btrfs: get rid of unique workqueue helper functions	2020-01-09 10:20:06 +01:00
raid56.h	btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes	2019-07-01 13:34:58 +02:00
rcu-string.h	btrfs: replace GPL boilerplate by SPDX -- headers	2018-04-12 16:29:46 +02:00
reada.c	btrfs: fix readahead hang and use-after-free after removing a device	2020-11-05 11:43:27 +01:00
ref-verify.c	btrfs: ref-verify: fix memory leak in btrfs_ref_tree_mod	2020-11-18 19:20:28 +01:00
ref-verify.h	btrfs: ref-verify: Use btrfs_ref to refactor btrfs_ref_tree_mod()	2019-04-29 19:02:49 +02:00
relocation.c	btrfs: fix min reserved size calculation in merge_reloc_root	2020-11-18 19:20:28 +01:00
root-tree.c	btrfs: do not delete mismatched root refs	2020-01-23 08:22:40 +01:00
scrub.c	btrfs: allocate scrub workqueues outside of locks	2020-09-09 19:12:31 +02:00
send.c	btrfs: use kvzalloc() to allocate clone_roots in btrfs_ioctl_send()	2020-11-05 11:43:26 +01:00
send.h	btrfs: replace GPL boilerplate by SPDX -- headers	2018-04-12 16:29:46 +02:00
space-info.c	btrfs: take overcommit into account in inc_block_group_ro	2020-10-17 10:11:21 +02:00
space-info.h	btrfs: take overcommit into account in inc_block_group_ro	2020-10-17 10:11:21 +02:00
struct-funcs.c	btrfs: tie extent buffer and it's token together	2019-09-09 14:59:16 +02:00
super.c	btrfs: reset compression level for lzo on remount	2020-09-03 11:27:02 +02:00
sysfs.c	btrfs: sysfs: use NOFS for device creation	2020-08-21 13:05:22 +02:00
sysfs.h	btrfs: sysfs: move helper macros to sysfs.c	2019-09-09 14:59:08 +02:00
transaction.c	btrfs: add wrapper for transaction abort predicate	2020-08-26 10:40:49 +02:00
transaction.h	btrfs: add wrapper for transaction abort predicate	2020-08-26 10:40:49 +02:00
tree-checker.c	btrfs: tree-checker: add missing returns after data_ref alignment checks	2020-12-02 08:49:45 +01:00
tree-checker.h	btrfs: get fs_info from eb in btrfs_check_chunk_valid	2019-04-29 19:02:39 +02:00
tree-defrag.c	btrfs: open code now trivial btrfs_set_lock_blocking	2019-02-25 14:13:27 +01:00
tree-log.c	btrfs: reschedule if necessary when logging directory items	2020-11-05 11:43:26 +01:00
tree-log.h	btrfs: get fs_info from trans in btrfs_set_log_full_commit	2019-04-29 19:02:41 +02:00
ulist.c	btrfs: replace GPL boilerplate by SPDX -- sources	2018-04-12 16:29:51 +02:00
ulist.h	btrfs: replace GPL boilerplate by SPDX -- headers	2018-04-12 16:29:46 +02:00
uuid-tree.c	btrfs: handle ENOENT in btrfs_uuid_tree_iterate	2019-12-31 16:42:05 +01:00
volumes.c	btrfs: trim: fix underflow in trim length to prevent access beyond device boundary	2020-12-30 11:51:37 +01:00
volumes.h	btrfs: fix readahead hang and use-after-free after removing a device	2020-11-05 11:43:27 +01:00
xattr.c	Btrfs: fix failure to persist compression property xattr deletion on fsync	2019-06-17 16:37:17 +02:00
xattr.h	btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter	2019-04-29 19:02:44 +02:00
zlib.c	btrfs: compression: replace set_level callbacks by a common helper	2019-09-09 14:59:11 +02:00
zstd.c	btrfs: move cond_wake_up functions out of ctree	2019-09-09 14:59:15 +02:00