linux/fs/xfs
Brian Foster c2b3164320 xfs: use the latest extent at writeback delalloc conversion time
The writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping outside of the current
page. This is because the ilock is cycled between the time the
caller originally looked up the mapping and across each real
allocation of the provided file range. This code has collected
various hacks over the years to help combat the symptoms of these
races (i.e., truncate race detection, allocation into hole
detection, etc.), but none address the fundamental problem that the
imap may not be valid at allocation time.

Rather than continue to use race detection hacks, update writeback
delalloc conversion to a model that explicitly converts the delalloc
extent backing the current file offset being processed. The current
file offset is the only block we can trust to remain once the ilock
is dropped because any operation that can remove the block
(truncate, hole punch, etc.) must flush and discard pagecache pages
first.

Modify xfs_iomap_write_allocate() to use the xfs_bmapi_delalloc()
mechanism to request allocation of the entire delalloc extent
backing the current offset instead of assuming the extent passed by
the caller is unchanged. Record the range specified by the caller
and apply it to the resulting allocated extent so previous checks by
the caller for COW fork overlap are not lost. Finally, overload the
bmapi delalloc flag with the range reval flag behavior since this is
the only use case for both.

This ensures that writeback always picks up the correct
and current extent associated with the page, regardless of races
with other extent modifying operations. If operating on a data fork
and the COW overlap state has changed since the ilock was cycled,
the caller revalidates against the COW fork sequence number before
using the imap for the next block.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-11 16:07:01 -08:00
..
libxfs xfs: use the latest extent at writeback delalloc conversion time 2019-02-11 16:07:01 -08:00
scrub xfs: check attribute name validity 2019-02-11 16:06:40 -08:00
Kconfig xfs: implement the metadata repair ioctl flag 2018-05-15 18:12:50 -07:00
kmem.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
kmem.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
Makefile xfs: move the repair extent list into its own file 2018-07-29 22:37:09 -07:00
mrlock.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_acl.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_acl.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_aops.c xfs: remove superfluous writeback mapping eof trimming 2019-02-11 16:07:01 -08:00
xfs_aops.h xfs: fix symbolic enum printing in ftrace output 2018-12-19 14:02:01 -08:00
xfs_attr_inactive.c xfs: remove all boilerplate defer init/finish code 2018-07-26 10:15:15 -07:00
xfs_attr_list.c xfs: substitute spaces with tabs 2018-08-02 23:05:14 -07:00
xfs_bmap_item.c xfs: pass transaction to xfs_defer_add() 2018-08-02 23:05:14 -07:00
xfs_bmap_item.h xfs: use transaction for intent recovery instead of raw dfops 2018-08-02 23:05:13 -07:00
xfs_bmap_util.c xfs: fix PAGE_MASK usage in xfs_free_file_space 2018-12-04 08:50:49 -08:00
xfs_bmap_util.h xfs: flush removing page cache in xfs_reflink_remap_prep 2018-11-21 10:10:53 -08:00
xfs_buf_item.c xfs: fix transient reference count error in xfs_buf_resubmit_failed_buffers 2018-11-20 10:36:01 -08:00
xfs_buf_item.h xfs: refactor xfs_buf_log_item reference count handling 2018-09-29 13:45:26 +10:00
xfs_buf.c xfs: set buffer ops when repair probes for btree type 2019-02-03 14:03:59 -08:00
xfs_buf.h xfs: always assign buffer verifiers when one is provided 2018-10-18 17:20:30 +11:00
xfs_dir2_readdir.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_discard.c xfs: trivial xfs_btree_del_cursor cleanups 2018-07-23 09:08:00 -07:00
xfs_discard.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_dquot_item.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_dquot_item.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_dquot.c xfs: remove dead error handling code in xfs_dquot_disk_alloc() 2018-08-07 10:57:13 -07:00
xfs_dquot.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_error.c xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask 2019-02-11 16:07:00 -08:00
xfs_error.h xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask 2019-02-11 16:07:00 -08:00
xfs_export.c xfs: clean up IRELE/iput callsites 2018-07-26 10:15:16 -07:00
xfs_export.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_extent_busy.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_extent_busy.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_extfree_item.c xfs: remove xfs_rmap_ag_owner and friends 2018-12-12 08:47:16 -08:00
xfs_extfree_item.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_file.c xfs: make xfs_file_remap_range() static 2018-11-19 13:30:38 -08:00
xfs_filestream.c xfs: replace dop_low with transaction flag 2018-08-02 23:05:13 -07:00
xfs_filestream.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_fsmap.c xfs: trivial xfs_btree_del_cursor cleanups 2018-07-23 09:08:00 -07:00
xfs_fsmap.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_fsops.c xfs: xfs_fsops: drop useless LIST_HEAD 2018-12-29 10:47:58 -08:00
xfs_fsops.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_globals.c xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask 2019-02-11 16:07:00 -08:00
xfs_icache.c xfs: introduce a new xfs_inode_has_cow_data helper 2018-07-30 07:57:48 -07:00
xfs_icache.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_icreate_item.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_icreate_item.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_inode_item.c xfs: remove if_real_bytes 2018-07-30 07:57:48 -07:00
xfs_inode_item.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_inode.c xfs: precalculate inodes and blocks per inode cluster 2018-12-12 08:47:17 -08:00
xfs_inode.h xfs: fold dfops into the transaction 2018-08-02 23:05:14 -07:00
xfs_ioctl32.c xfs: Fix x32 ioctls when cmd numbers differ from ia32. 2018-12-18 10:55:21 -08:00
xfs_ioctl32.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_ioctl.c xfs: Fix error code in 'xfs_ioc_getbmap()' 2018-11-06 07:50:50 -08:00
xfs_ioctl.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_iomap.c xfs: use the latest extent at writeback delalloc conversion time 2019-02-11 16:07:01 -08:00
xfs_iomap.h xfs: avoid COW fork extent lookups in writeback if the fork didn't change 2018-07-31 13:18:09 -07:00
xfs_iops.c xfs: don't crash the vfs on a garbage inline symlink 2018-09-29 13:40:40 +10:00
xfs_iops.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_itable.c xfs: precalculate inodes and blocks per inode cluster 2018-12-12 08:47:17 -08:00
xfs_itable.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_linux.h xfs: replace do_mod with native operations 2018-06-08 10:07:52 -07:00
xfs_log_cil.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_log_priv.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_log_recover.c xfs: precalculate inodes and blocks per inode cluster 2018-12-12 08:47:17 -08:00
xfs_log.c xfs: fix a comment in xfs_log_reserve 2018-08-03 08:17:54 -07:00
xfs_log.h xfs: refactor log recovery check 2018-08-01 07:40:48 -07:00
xfs_message.c xfs: print buffer offsets when dumping corrupt buffers 2018-11-06 07:50:50 -08:00
xfs_message.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_mount.c xfs: precalculate cluster alignment in inodes and blocks 2018-12-12 08:47:17 -08:00
xfs_mount.h xfs: cache minimum realtime summary level 2018-12-12 08:47:17 -08:00
xfs_mru_cache.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_mru_cache.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_ondisk.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_pnfs.c xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_pnfs.h xfs: prepare xfs_break_layouts() for another layout type 2018-05-22 07:19:08 -07:00
xfs_qm_bhv.c fs/xfs: fix f_ffree value for statfs when project quota is set 2018-11-26 15:01:37 -08:00
xfs_qm_syscalls.c xfs: clean up IRELE/iput callsites 2018-07-26 10:15:16 -07:00
xfs_qm.c xfs: clean up IRELE/iput callsites 2018-07-26 10:15:16 -07:00
xfs_qm.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_quota.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_quotaops.c xfs: clean up IRELE/iput callsites 2018-07-26 10:15:16 -07:00
xfs_refcount_item.c xfs: pass transaction to xfs_defer_add() 2018-08-02 23:05:14 -07:00
xfs_refcount_item.h xfs: use transaction for intent recovery instead of raw dfops 2018-08-02 23:05:13 -07:00
xfs_reflink.c xfs: split up the xfs_reflink_end_cow work into smaller transactions 2018-12-12 08:46:19 -08:00
xfs_reflink.h vfs: rework data cloning infrastructure 2018-11-02 09:33:08 -07:00
xfs_rmap_item.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_rmap_item.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_rtalloc.c xfs: reallocate realtime summary cache on growfs 2018-12-21 18:45:18 -08:00
xfs_rtalloc.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_stats.c xfs: use offsetof() in place of offset macros for __xfsstats 2018-10-18 17:21:39 +11:00
xfs_stats.h xfs: use offsetof() in place of offset macros for __xfsstats 2018-10-18 17:21:39 +11:00
xfs_super.c xfs: add a block to inode count converter 2018-12-12 08:47:16 -08:00
xfs_super.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_symlink.c xfs: zero length symlinks are not valid 2018-12-12 08:47:15 -08:00
xfs_symlink.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_sysctl.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_sysctl.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_sysfs.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_sysfs.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_trace.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_trace.h xfs: stringify btree cursor types in ftrace output 2018-12-19 14:02:01 -08:00
xfs_trans_ail.c xfs: clear ail delwri queued bufs on unmount of shutdown fs 2018-10-18 17:21:49 +11:00
xfs_trans_bmap.c xfs: remove duplicated xfs_defer.h 2019-02-11 16:07:00 -08:00
xfs_trans_buf.c xfs: fix buffer state management in xrep_findroot_block 2018-10-18 17:20:35 +11:00
xfs_trans_dquot.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_trans_extfree.c xfs: remove duplicated xfs_defer.h 2019-02-11 16:07:00 -08:00
xfs_trans_inode.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
xfs_trans_priv.h xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs_trans_refcount.c xfs: remove duplicated xfs_defer.h 2019-02-11 16:07:00 -08:00
xfs_trans_rmap.c xfs: remove duplicated xfs_defer.h 2019-02-11 16:07:00 -08:00
xfs_trans.c xfs: avoid lockdep false positives in xfs_trans_alloc 2018-09-29 13:46:21 +10:00
xfs_trans.h xfs: const-ify xfs_owner_info arguments 2018-12-12 08:47:16 -08:00
xfs_xattr.c xfs: convert to SPDX license tags 2018-06-06 14:17:53 -07:00
xfs.h xfs: remove b_last_holder & associated macros 2018-08-12 08:37:31 -07:00