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| author | Anna Schumaker <Anna.Schumaker@netapp.com> | 2015-11-10 22:53:33 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-12-01 20:00:55 +0100 |
| commit | eac70053a141998c40907747d6cea1d53a9414be (patch) | |
| tree | 67b51897837e7e031727afd38596e9d5eb10e196 /fs/read_write.c | |
| parent | btrfs: add .copy_file_range file operation (diff) | |
| download | linux-eac70053a141998c40907747d6cea1d53a9414be.tar.xz linux-eac70053a141998c40907747d6cea1d53a9414be.zip | |
vfs: Add vfs_copy_file_range() support for pagecache copies
This allows us to have an in-kernel copy mechanism that avoids frequent
switches between kernel and user space. This is especially useful so
NFSD can support server-side copies.
The default (flags=0) means to first attempt copy acceleration, but use
the pagecache if that fails.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Padraig Brady <P@draigBrady.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 173140029a7a..c81ef394a3d4 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1354,8 +1354,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (!(file_in->f_mode & FMODE_READ) || !(file_out->f_mode & FMODE_WRITE) || - (file_out->f_flags & O_APPEND) || - !file_out->f_op->copy_file_range) + (file_out->f_flags & O_APPEND)) return -EBADF; /* this could be relaxed once a method supports cross-fs copies */ @@ -1369,8 +1368,14 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (ret) return ret; - ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, - len, flags); + ret = -EOPNOTSUPP; + if (file_out->f_op->copy_file_range) + ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, + pos_out, len, flags); + if (ret == -EOPNOTSUPP) + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, + len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + if (ret > 0) { fsnotify_access(file_in); add_rchar(current, ret); |