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| author | Nikolay Borisov | 2017-08-01 17:25:56 +0200 |
|---|---|---|
| committer | David Sterba | 2017-08-21 18:49:21 +0200 |
| commit | dc59215d4f42084ee13654bafe3e5130b146aeb7 (patch) | |
| tree | 3a94053e30f88d9064f79a3afe5ffdcc937ab309 /drivers/usb/dwc3/dwc3-omap.c | |
| parent | btrfs: remove superfluous chunk_tree argument from btrfs_alloc_dev_extent (diff) | |
| download | kernel-qcow2-linux-dc59215d4f42084ee13654bafe3e5130b146aeb7.tar.gz kernel-qcow2-linux-dc59215d4f42084ee13654bafe3e5130b146aeb7.tar.xz kernel-qcow2-linux-dc59215d4f42084ee13654bafe3e5130b146aeb7.zip | |
btrfs: remove unnecessary memory barrier in btrfs_direct_IO
Commit 38851cc19adb ("Btrfs: implement unlocked dio write") implemented
unlocked dio write, allowing multiple dio writers to write to
non-overlapping, and non-eof-extending regions. In doing so it also
introduced a broken memory barrier. It is broken due to 2 things:
1. Memory barriers _MUST_ always be paired, this is clearly not the case
here
2. Checkpatch actually produces a warning if a memory barrier is
introduced that doesn't have a comment explaining how it's being
paired.
Specifically for inode::i_dio_count that's wrapped inside
inode_dio_begin, there is no explicit barrier semantics attached, so
removing is fine as the atomic is used in common the waiter/wakeup
pattern.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'drivers/usb/dwc3/dwc3-omap.c')
0 files changed, 0 insertions, 0 deletions