@@ -274,13 +274,17 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
return -EINVAL;
/*
- * Seal block map operation should only be used exclusively, and
- * with the IMMUTABLE capability.
+ * Seal/unseal block map operations should only be used
+ * exclusively, and with the IMMUTABLE capability.
*/
- if (mode & FALLOC_FL_SEAL_BLOCK_MAP) {
+ if (mode & (FALLOC_FL_SEAL_BLOCK_MAP | FALLOC_FL_UNSEAL_BLOCK_MAP)) {
if (!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
- if (mode & ~FALLOC_FL_SEAL_BLOCK_MAP)
+ if (mode == (FALLOC_FL_SEAL_BLOCK_MAP
+ | FALLOC_FL_UNSEAL_BLOCK_MAP))
+ return -EINVAL;
+ if (mode & ~(FALLOC_FL_SEAL_BLOCK_MAP
+ | FALLOC_FL_UNSEAL_BLOCK_MAP))
return -EINVAL;
}
@@ -303,10 +307,12 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
return -ETXTBSY;
/*
- * We cannot allow any allocation changes on an iomap immutable file,
- * but we can allow the fs to validate if this request is redundant.
+ * We cannot allow any allocation changes on an iomap immutable
+ * file, but we can allow the fs to validate if this request is
+ * redundant, or unseal the block map.
*/
- if (IS_IOMAP_IMMUTABLE(inode) && !(mode & FALLOC_FL_SEAL_BLOCK_MAP))
+ if (IS_IOMAP_IMMUTABLE(inode) && !(mode & (FALLOC_FL_SEAL_BLOCK_MAP
+ | FALLOC_FL_UNSEAL_BLOCK_MAP)))
return -ETXTBSY;
/*
@@ -1462,6 +1462,53 @@ xfs_seal_file_space(
return error;
}
+int
+xfs_unseal_file_space(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ xfs_off_t len)
+{
+ struct inode *inode = VFS_I(ip);
+ struct address_space *mapping = inode->i_mapping;
+ int error;
+
+ ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL));
+
+ if (offset)
+ return -EINVAL;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ /*
+ * It does not make sense to unseal less than the full range of
+ * the file.
+ */
+ error = -EINVAL;
+ if (len != i_size_read(inode))
+ goto out_unlock;
+
+ /* Are we already unsealed? */
+ error = 0;
+ if (!IS_IOMAP_IMMUTABLE(inode))
+ goto out_unlock;
+
+ /*
+ * Provide safety against one thread changing the policy of not
+ * requiring fsync/msync (for block allocations) behind another
+ * thread's back.
+ */
+ error = -EBUSY;
+ if (mapping_mapped(mapping))
+ goto out_unlock;
+
+ error = 0;
+ inode->i_flags &= ~S_IOMAP_IMMUTABLE;
+
+out_unlock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
+ return error;
+}
+
/*
* @next_fsb will keep track of the extent currently undergoing shift.
* @stop_fsb will keep track of the extent at which we have to stop.
@@ -62,6 +62,9 @@ int xfs_insert_file_space(struct xfs_inode *, xfs_off_t offset,
xfs_off_t len);
int xfs_seal_file_space(struct xfs_inode *, xfs_off_t offset,
xfs_off_t len);
+int xfs_unseal_file_space(struct xfs_inode *, xfs_off_t offset,
+ xfs_off_t len);
+
/* EOF block manipulation functions */
bool xfs_can_free_eofblocks(struct xfs_inode *ip, bool force);
@@ -740,7 +740,7 @@ xfs_file_write_iter(
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE | \
- FALLOC_FL_SEAL_BLOCK_MAP)
+ FALLOC_FL_SEAL_BLOCK_MAP | FALLOC_FL_UNSEAL_BLOCK_MAP)
STATIC long
xfs_file_fallocate(
@@ -840,6 +840,8 @@ xfs_file_fallocate(
XFS_BMAPI_PREALLOC);
} else if (mode & FALLOC_FL_SEAL_BLOCK_MAP) {
error = xfs_seal_file_space(ip, offset, len);
+ } else if (mode & FALLOC_FL_UNSEAL_BLOCK_MAP) {
+ error = xfs_unseal_file_space(ip, offset, len);
} else
error = xfs_alloc_file_space(ip, offset, len,
XFS_BMAPI_PREALLOC);
@@ -27,6 +27,7 @@ struct space_resv {
FALLOC_FL_ZERO_RANGE | \
FALLOC_FL_INSERT_RANGE | \
FALLOC_FL_UNSHARE_RANGE | \
- FALLOC_FL_SEAL_BLOCK_MAP)
+ FALLOC_FL_SEAL_BLOCK_MAP | \
+ FALLOC_FL_UNSEAL_BLOCK_MAP)
#endif /* _FALLOC_H_ */
@@ -93,4 +93,5 @@
* with the punch, zero, collapse, or insert range modes.
*/
#define FALLOC_FL_SEAL_BLOCK_MAP 0x080
+#define FALLOC_FL_UNSEAL_BLOCK_MAP 0x100
#endif /* _UAPI_FALLOC_H_ */
Provide an explicit fallocate operation type for clearing the S_IOMAP_IMMUTABLE flag. Like the enable case it requires CAP_IMMUTABLE and it can only be performed while no process has the file mapped. Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- fs/open.c | 20 ++++++++++++------ fs/xfs/xfs_bmap_util.c | 47 +++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_bmap_util.h | 3 +++ fs/xfs/xfs_file.c | 4 +++- include/linux/falloc.h | 3 ++- include/uapi/linux/falloc.h | 1 + 6 files changed, 69 insertions(+), 9 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html