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| author |   Darrick J. Wong <darrick.wong@oracle.com> | 2018-10-30 10:42:10 +1100 |
|---|---|---|
| committer |   Dave Chinner <david@fromorbit.com> | 2018-10-30 10:42:10 +1100 |
| commit | eca3654e3cc7d93e9734d0fa96cfb15c7f356244 (patch) | |
| tree | 00e5f8bd5de34435872d8cb222daaec79ede3961 /Documentation/filesystems | |
| parent | vfs: plumb remap flags through the vfs dedupe functions (diff) | |
| download | linux-dev-eca3654e3cc7d93e9734d0fa96cfb15c7f356244.tar.xz linux-dev-eca3654e3cc7d93e9734d0fa96cfb15c7f356244.zip | |
vfs: enable remap callers that can handle short operations
Plumb in a remap flag that enables the filesystem remap handler to
shorten remapping requests for callers that can handle it. Now
copy_file_range can report partial success (in case we run up against
alignment problems, resource limits, etc.).
We also enable CAN_SHORTEN for fideduperange to maintain existing
userspace-visible behavior where xfs/btrfs shorten the dedupe range to
avoid stale post-eof data exposure.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 1bd2919deaca..5f71a252e2e0 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -970,7 +970,9 @@ otherwise noted. negative error code if errors occurred before any bytes were remapped. The remap_flags parameter accepts REMAP_FILE_* flags. If REMAP_FILE_DEDUP is set then the implementation must only remap if the - requested file ranges have identical contents. + requested file ranges have identical contents. If REMAP_CAN_SHORTEN is + set, the caller is ok with the implementation shortening the request + length to satisfy alignment or EOF requirements (or any other reason). fadvise: possibly called by the fadvise64() system call. |