linux/fs/xfs
Darrick J. Wong 6d8a45ce29 xfs: don't screw up direct writes when freesp is fragmented
xfs_bmap_btalloc is given a range of file offset blocks that must be
allocated to some data/attr/cow fork.  If the fork has an extent size
hint associated with it, the request will be enlarged on both ends to
try to satisfy the alignment hint.  If free space is fragmentated,
sometimes we can allocate some blocks but not enough to fulfill any of
the requested range.  Since bmapi_allocate always trims the new extent
mapping to match the originally requested range, this results in
bmapi_write returning zero and no mapping.

The consequences of this vary -- buffered writes will simply re-call
bmapi_write until it can satisfy at least one block from the original
request.  Direct IO overwrites notice nmaps == 0 and return -ENOSPC
through the dio mechanism out to userspace with the weird result that
writes fail even when we have enough space because the ENOSPC return
overrides any partial write status.  For direct CoW writes the situation
was disastrous because nobody notices us returning an invalid zero-length
wrong-offset mapping to iomap and the write goes off into space.

Therefore, if free space is so fragmented that we managed to allocate
some space but not enough to map into even a single block of the
original allocation request range, we should break the alignment hint in
order to guarantee at least some forward progress for the direct write.
If we return a short allocation to iomap_apply it'll call back about the
remaining blocks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-01-29 07:27:24 -08:00
..
libxfs xfs: don't screw up direct writes when freesp is fragmented 2018-01-29 07:27:24 -08:00
scrub xfs: don't clobber inobt/finobt cursors when xref with rmap 2018-01-29 07:27:23 -08:00
Kconfig xfs: create an ioctl to scrub AG metadata 2017-10-26 15:38:23 -07:00
kmem.c mm, vmalloc: use __GFP_HIGHMEM implicitly 2017-05-08 17:15:13 -07:00
kmem.h slab, slub, slob: add slab_flags_t 2017-11-15 18:21:01 -08:00
Makefile xfs: use a b+tree for the in-core extent list 2017-11-06 11:53:41 -08:00
mrlock.h
xfs_acl.c xfs: don't change inode mode if ACL update fails 2017-10-11 10:21:06 -07:00
xfs_acl.h xfs: Don't clear SGID when inheriting ACLs 2017-06-27 18:23:21 -07:00
xfs_aops.c xfs: skip CoW writes past EOF when writeback races with truncate 2018-01-29 07:27:23 -08:00
xfs_aops.h xfs: perform dax_device lookup at mount 2017-08-31 09:31:47 -07:00
xfs_attr_inactive.c xfs: fail if xattr inactivation hits a hole 2017-10-26 15:38:22 -07:00
xfs_attr_list.c xfs: remove u_int* type usage 2017-11-09 15:50:29 -08:00
xfs_attr.h xfs: scrub extended attributes 2017-10-26 15:38:26 -07:00
xfs_bmap_item.c xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_bmap_item.h xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_bmap_util.c xfs: allow xfs_lock_two_inodes to take different EXCL/SHARED modes 2018-01-29 07:27:23 -08:00
xfs_bmap_util.h xfs: simplify the xfs_getbmap interface 2017-10-26 15:38:20 -07:00
xfs_buf_item.c Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_buf_item.h Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_buf.c Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_buf.h Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_dir2_readdir.c xfs: directory scrubber must walk through data block to offset 2018-01-17 21:00:46 -08:00
xfs_discard.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -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 Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_dquot_item.h
xfs_dquot.c xfs: standardize quota verification function outputs 2018-01-08 10:54:47 -08:00
xfs_dquot.h
xfs_error.c xfs: refactor inode verifier corruption error printing 2018-01-29 07:27:22 -08:00
xfs_error.h xfs: refactor inode verifier corruption error printing 2018-01-29 07:27:22 -08:00
xfs_export.c
xfs_export.h
xfs_extent_busy.c xfs: fix len comparison in xfs_extent_busy_trim 2017-02-16 17:20:12 -08:00
xfs_extent_busy.h xfs: improve handling of busy extents in the low-level allocator 2017-02-09 10:50:25 -08:00
xfs_extfree_item.c xfs: always honor OWN_UNKNOWN rmap removal requests 2017-12-21 08:48:38 -08:00
xfs_extfree_item.h
xfs_file.c libnvdimm for 4.15 2017-11-17 09:51:57 -08:00
xfs_filestream.c
xfs_filestream.h
xfs_fsmap.c xfs: move two more RT specific functions into CONFIG_XFS_RT 2017-10-16 12:26:50 -07:00
xfs_fsmap.h xfs: implement the GETFSMAP ioctl 2017-04-03 15:18:17 -07:00
xfs_fsops.c xfs: use %px for data pointers when debugging 2018-01-12 14:09:08 -08:00
xfs_fsops.h xfs: hoist xfs_fs_geometry to libxfs 2018-01-08 10:54:48 -08:00
xfs_globals.c xfs: define fatal assert build time tunable 2017-06-19 08:59:10 -07:00
xfs_icache.c xfs: preserve i_rdev when recycling a reclaimable inode 2018-01-29 07:27:23 -08:00
xfs_icache.h xfs: remove leftover CoW reservations when remounting ro 2017-12-21 08:47:32 -08:00
xfs_icreate_item.c fs: xfs: xfs_icreate_item: constify xfs_item_ops structure 2016-11-28 14:57:42 +11:00
xfs_icreate_item.h
xfs_inode_item.c Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_inode_item.h xfs: remove inode log format typedef 2017-11-01 15:03:16 -07:00
xfs_inode.c xfs: allow xfs_lock_two_inodes to take different EXCL/SHARED modes 2018-01-29 07:27:23 -08:00
xfs_inode.h xfs: allow xfs_lock_two_inodes to take different EXCL/SHARED modes 2018-01-29 07:27:23 -08:00
xfs_ioctl32.c xfs: refactor the geometry structure filling function 2018-01-08 10:54:48 -08:00
xfs_ioctl32.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_ioctl.c xfs: refactor the geometry structure filling function 2018-01-08 10:54:48 -08:00
xfs_ioctl.h xfs: remove u_int* type usage 2017-11-09 15:50:29 -08:00
xfs_iomap.c xfs: fix s_maxbytes overflow problems 2018-01-02 10:16:32 -08:00
xfs_iomap.h xfs: update i_size after unwritten conversion in dio completion 2017-09-26 10:55:19 -07:00
xfs_iops.c xfs: truncate pagecache before writeback in xfs_setattr_size() 2017-11-03 09:45:56 -07:00
xfs_iops.h
xfs_itable.c xfs: remove if_rdev 2017-10-26 15:38:27 -07:00
xfs_itable.h xfs: create inode pointer verifiers 2017-10-26 15:38:23 -07:00
xfs_linux.h xfs: use %px for data pointers when debugging 2018-01-12 14:09:08 -08:00
xfs_log_cil.c xfs: Fix leak of discard bio 2017-08-04 13:43:36 -07:00
xfs_log_priv.h locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
xfs_log_recover.c Split buffer's b_fspriv field 2018-01-29 07:27:22 -08:00
xfs_log.c Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_log.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_message.c xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
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: destroy mutex pag_ici_reclaim_lock before free 2018-01-12 14:09:08 -08:00
xfs_mount.h xfs: convert drop_writes to use the errortag mechanism 2017-06-27 18:23:20 -07:00
xfs_mru_cache.c
xfs_mru_cache.h
xfs_ondisk.h xfs: Don't log uninitialised fields in inode structures 2017-10-11 10:21:06 -07:00
xfs_pnfs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_pnfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs_qm_bhv.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_qm_syscalls.c xfs: wait on new inodes during quotaoff dquot release 2017-04-28 08:11:08 -07:00
xfs_qm.c xfs: use %px for data pointers when debugging 2018-01-12 14:09:08 -08:00
xfs_qm.h
xfs_quota.h
xfs_quotaops.c VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) 2017-07-17 08:45:34 +01:00
xfs_refcount_item.c xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_refcount_item.h xfs: log recovery should replay deferred ops in order 2017-11-27 09:34:08 -08:00
xfs_reflink.c xfs: check reflink allocation mappings 2018-01-29 07:27:24 -08:00
xfs_reflink.h xfs: separate function to check if inode shares extents 2017-06-19 14:11:35 -07:00
xfs_rmap_item.c xfs: better log intent item refcount checking 2017-04-25 09:40:42 -07:00
xfs_rmap_item.h
xfs_rtalloc.c xfs: remove the ip argument to xfs_defer_finish 2017-09-01 10:55:30 -07:00
xfs_rtalloc.h xfs: cross-reference the realtime bitmap 2018-01-17 21:00:46 -08:00
xfs_stats.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_stats.h xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_super.c xfs: Show realtime device stats on statfs calls if realtime flags set 2018-01-08 10:41:33 -08:00
xfs_super.h Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
xfs_symlink.c xfs: remove "no-allocation" reservations for file creations 2017-12-08 17:51:05 -08:00
xfs_symlink.h xfs: allow reading of already-locked remote symbolic link 2017-06-20 10:45:22 -07:00
xfs_sysctl.c xfs: garbage collect old cowextsz reservations 2016-10-05 16:26:28 -07:00
xfs_sysctl.h xfs: define bug_on_assert debug mode sysfs tunable 2017-06-19 08:59:10 -07:00
xfs_sysfs.c xfs: replace log_badcrc_factor knob with error injection tag 2017-06-27 18:23:21 -07:00
xfs_sysfs.h
xfs_trace.c fs: xfs: remove duplicate includes 2017-12-08 17:51:05 -08:00
xfs_trace.h xfs: use %pS printk format for direct instruction addresses 2018-01-12 14:09:08 -08:00
xfs_trans_ail.c xfs: move error injection tags into their own file 2017-11-01 15:03:16 -07:00
xfs_trans_bmap.c xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent 2017-06-19 08:59:10 -07:00
xfs_trans_buf.c Split buffer's b_fspriv field 2018-01-29 07:27:22 -08:00
xfs_trans_dquot.c
xfs_trans_extfree.c
xfs_trans_inode.c xfs: refactor xfs_trans_roll 2017-09-01 10:55:30 -07:00
xfs_trans_priv.h xfs: Properly retry failed inode items in case of error during buffer writeback 2017-08-22 09:22:23 -07:00
xfs_trans_refcount.c xfs: connect refcount adjust functions to upper layers 2016-10-03 09:11:22 -07:00
xfs_trans_rmap.c xfs: remove double-underscore integer types 2017-06-19 14:11:33 -07:00
xfs_trans.c xfs: trace log reservations at mount time 2018-01-08 10:54:47 -08:00
xfs_trans.h Use list_head infra-structure for buffer's log items list 2018-01-29 07:27:22 -08:00
xfs_xattr.c xfs: several xattr functions can be void 2016-12-05 12:32:14 +11:00
xfs.h xfs: always define STATIC to static noinline 2017-11-06 11:53:58 -08:00