xfs: Add support FALLOC_FL_COLLAPSE_RANGE for fallocate

This patch implements fallocate's FALLOC_FL_COLLAPSE_RANGE for XFS.

The semantics of this flag are following:
1) It collapses the range lying between offset and length by removing any data
   blocks which are present in this range and than updates all the logical
   offsets of extents beyond "offset + len" to nullify the hole created by
   removing blocks. In short, it does not leave a hole.
2) It should be used exclusively. No other fallocate flag in combination.
3) Offset and length supplied to fallocate should be fs block size aligned
   in case of xfs and ext4.
4) Collaspe range does not work beyond i_size.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Namjae Jeon
2014-02-24 10:58:19 +11:00
committed by Dave Chinner
parent 00f5e61998
commit e1d8fb88a6
6 changed files with 324 additions and 3 deletions

View File

@@ -603,6 +603,7 @@ DEFINE_INODE_EVENT(xfs_readlink);
DEFINE_INODE_EVENT(xfs_inactive_symlink);
DEFINE_INODE_EVENT(xfs_alloc_file_space);
DEFINE_INODE_EVENT(xfs_free_file_space);
DEFINE_INODE_EVENT(xfs_collapse_file_space);
DEFINE_INODE_EVENT(xfs_readdir);
#ifdef CONFIG_XFS_POSIX_ACL
DEFINE_INODE_EVENT(xfs_get_acl);