xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate
This patch implements fallocate's FALLOC_FL_INSERT_RANGE for XFS.
1) Make sure that both offset and len are block size aligned.
2) Update the i_size of inode by len bytes.
3) Compute the file's logical block number against offset. If the computed
block number is not the starting block of the extent, split the extent
such that the block number is the starting block of the extent.
4) Shift all the extents which are lying bewteen [offset, last allocated extent]
towards right by len bytes. This step will make a hole of len bytes
at offset.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ce615d1..edeaccc 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -816,6 +816,11 @@
return ret;
}
+#define XFS_FALLOC_FL_SUPPORTED \
+ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
+ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
+ FALLOC_FL_INSERT_RANGE)
+
STATIC long
xfs_file_fallocate(
struct file *file,
@@ -829,11 +834,11 @@
enum xfs_prealloc_flags flags = 0;
uint iolock = XFS_IOLOCK_EXCL;
loff_t new_size = 0;
+ bool do_file_insert = 0;
if (!S_ISREG(inode->i_mode))
return -EINVAL;
- if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
- FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+ if (mode & ~XFS_FALLOC_FL_SUPPORTED)
return -EOPNOTSUPP;
xfs_ilock(ip, iolock);
@@ -867,6 +872,27 @@
error = xfs_collapse_file_space(ip, offset, len);
if (error)
goto out_unlock;
+ } else if (mode & FALLOC_FL_INSERT_RANGE) {
+ unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
+
+ new_size = i_size_read(inode) + len;
+ if (offset & blksize_mask || len & blksize_mask) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* check the new inode size does not wrap through zero */
+ if (new_size > inode->i_sb->s_maxbytes) {
+ error = -EFBIG;
+ goto out_unlock;
+ }
+
+ /* Offset should be less than i_size */
+ if (offset >= i_size_read(inode)) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+ do_file_insert = 1;
} else {
flags |= XFS_PREALLOC_SET;
@@ -901,8 +927,19 @@
iattr.ia_valid = ATTR_SIZE;
iattr.ia_size = new_size;
error = xfs_setattr_size(ip, &iattr);
+ if (error)
+ goto out_unlock;
}
+ /*
+ * Perform hole insertion now that the file size has been
+ * updated so that if we crash during the operation we don't
+ * leave shifted extents past EOF and hence losing access to
+ * the data that is contained within them.
+ */
+ if (do_file_insert)
+ error = xfs_insert_file_space(ip, offset, len);
+
out_unlock:
xfs_iunlock(ip, iolock);
return error;