linux/include
Amir Goldstein c553ea4fdf fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback
23d0127096 ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE
writeback") claims that sync_file_range(2) syscall was "created for
userspace to be able to issue background writeout and so waiting for
in-flight IO is undesirable there" and changes the writeback (back) to
WB_SYNC_NONE.

This claim is only partially true.  It is true for users that use the flag
SYNC_FILE_RANGE_WRITE by itself, as does PostgreSQL, the user that was the
reason for changing to WB_SYNC_NONE writeback.

However, that claim is not true for users that use that flag combination
SYNC_FILE_RANGE_{WAIT_BEFORE|WRITE|_WAIT_AFTER}.  Those users explicitly
requested to wait for in-flight IO as well as to writeback of dirty pages.

Re-brand that flag combination as SYNC_FILE_RANGE_WRITE_AND_WAIT and use
WB_SYNC_ALL writeback to perform the full range sync request.

Link: http://lkml.kernel.org/r/20190409114922.30095-1-amir73il@gmail.com
Link: http://lkml.kernel.org/r/20190419072938.31320-1-amir73il@gmail.com
Fixes: 23d0127096 ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Jan Kara <jack@suse.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:50 -07:00
..
acpi Driver core/kobject patches for 5.2-rc1 2019-05-07 13:01:40 -07:00
asm-generic hugetlb: allow to free gigantic pages regardless of the configuration 2019-05-14 09:47:47 -07:00
clocksource
crypto crypto: shash - remove shash_desc::flags 2019-04-25 15:38:12 +08:00
drm drm pull request for 5.2 2019-05-08 21:35:19 -07:00
dt-bindings We have a couple new features and changes in the core clk framework this time 2019-05-09 14:50:09 -07:00
keys
kvm
linux mm: introduce new vm_map_pages() and vm_map_pages_zero() API 2019-05-14 09:47:50 -07:00
math-emu
media drm pull request for 5.2 2019-05-08 21:35:19 -07:00
memory
misc ocxl: Provide global MMIO accessors for external drivers 2019-05-03 02:55:02 +10:00
net net/tcp: use deferred jump label for TCP acked data hook 2019-05-09 11:13:57 -07:00
pcmcia
ras
rdma RDMA: Add EFA related definitions 2019-05-06 13:47:50 -03:00
scsi scsi: libsas: Inject revalidate event for root port event 2019-04-15 18:55:00 -04:00
soc This pull request contains the following changes for MTD: 2019-05-12 17:57:52 -04:00
sound sound updates for 5.2-rc1 2019-05-09 08:26:55 -07:00
target scsi: target/iscsi: Handle too large immediate data buffers correctly 2019-04-12 20:20:06 -04:00
trace mm/vmscan: drop may_writepage and classzone_idx from direct reclaim begin template 2019-05-14 09:47:48 -07:00
uapi fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback 2019-05-14 09:47:50 -07:00
video
xen