[PATCH 3/3] xfs: persist S_IOMAP_IMMUTABLE in di_flags2

Dan Williams
2017-07-29T19:48:04Z

Record the immutable state in the on-disk inode so that on the next boot
the protections against reflink and hole punch etc are automatically
restored.

This deliberately does not add a FS_XFLAG_IOMAP_IMMUTABLE since
fallocate(2) is the path to toggle this flag.

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>
Suggested-by: Dave Chinner <david@fromorbit.com>
Suggested-by: "Darrick J. Wong" <darrick.wong@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
fs/xfs/libxfs/xfs_format.h | 5 ++++-
fs/xfs/xfs_bmap_util.c | 14 +++++++++++---
fs/xfs/xfs_bmap_util.h | 2 +-
fs/xfs/xfs_file.c | 4 ++--
fs/xfs/xfs_ioctl.c | 4 ++--
fs/xfs/xfs_iops.c | 8 +++++---
6 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index d4d9bef20c3a..9e720e55776b 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -1063,12 +1063,15 @@ static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
#define XFS_DIFLAG2_DAX_BIT 0 /* use DAX for this inode */
#define XFS_DIFLAG2_REFLINK_BIT 1 /* file's blocks may be shared */
#define XFS_DIFLAG2_COWEXTSIZE_BIT 2 /* copy on write extent size hint */
+#define XFS_DIFLAG2_IOMAP_IMMUTABLE_BIT 3 /* set S_IOMAP_IMMUTABLE for this inode */
#define XFS_DIFLAG2_DAX (1 << XFS_DIFLAG2_DAX_BIT)
#define XFS_DIFLAG2_REFLINK (1 << XFS_DIFLAG2_REFLINK_BIT)
#define XFS_DIFLAG2_COWEXTSIZE (1 << XFS_DIFLAG2_COWEXTSIZE_BIT)
+#define XFS_DIFLAG2_IOMAP_IMMUTABLE (1 << XFS_DIFLAG2_IOMAP_IMMUTABLE_BIT)

#define XFS_DIFLAG2_ANY \
- (XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE)
+ (XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
+ XFS_DIFLAG2_IOMAP_IMMUTABLE)

/*
* Inode number format:
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index c4fc79a0704f..1dcb521da456 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1021,7 +1021,8 @@ xfs_alloc_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len,
- int alloc_type)
+ int alloc_type,
+ uint64_t di_flags2)
{
xfs_mount_t *mp = ip->i_mount;
xfs_off_t count;
@@ -1119,6 +1120,12 @@ xfs_alloc_file_space(
break;
}
xfs_ilock(ip, XFS_ILOCK_EXCL);
+ if (di_flags2) {
+ /* fold inode attributes for this allocation */
+ ip->i_d.di_flags2 |= di_flags2;
+ di_flags2 = 0;
+ }
+
error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks,
0, quota_flag);
if (error)
@@ -1381,7 +1388,7 @@ xfs_zero_file_space(
error = xfs_alloc_file_space(ip, round_down(offset, blksize),
round_up(offset + len, blksize) -
round_down(offset, blksize),
- XFS_BMAPI_PREALLOC);
+ XFS_BMAPI_PREALLOC, 0);
out:
return error;

@@ -1461,7 +1468,8 @@ xfs_seal_file_space(
goto err;

error = xfs_alloc_file_space(ip, offset, len,
- XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO);
+ XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO,
+ XFS_DIFLAG2_IOMAP_IMMUTABLE);
if (error)
goto err;

diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index 5115a32a2483..1698e0c58b78 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -51,7 +51,7 @@ int xfs_bmap_last_extent(struct xfs_trans *tp, struct xfs_inode *ip,

/* preallocation and hole punch interface */
int xfs_alloc_file_space(struct xfs_inode *ip, xfs_off_t offset,
- xfs_off_t len, int alloc_type);
+ xfs_off_t len, int alloc_type, uint64_t di_flags2);
int xfs_free_file_space(struct xfs_inode *ip, xfs_off_t offset,
xfs_off_t len);
int xfs_zero_file_space(struct xfs_inode *ip, xfs_off_t offset,
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index e21121530a90..2d9ffa1773bd 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -837,12 +837,12 @@ xfs_file_fallocate(
goto out_unlock;

error = xfs_alloc_file_space(ip, offset, len,
- XFS_BMAPI_PREALLOC);
+ XFS_BMAPI_PREALLOC, 0);
} else if (mode & FALLOC_FL_SEAL_BLOCK_MAP) {
error = xfs_seal_file_space(ip, offset, len);
} else
error = xfs_alloc_file_space(ip, offset, len,
- XFS_BMAPI_PREALLOC);
+ XFS_BMAPI_PREALLOC, 0);
}
if (error)
goto out_unlock;
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 2e64488bc4de..c829f85bed99 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -703,7 +703,7 @@ xfs_ioc_space(
case XFS_IOC_RESVSP64:
flags |= XFS_PREALLOC_SET;
error = xfs_alloc_file_space(ip, bf->l_start, bf->l_len,
- XFS_BMAPI_PREALLOC);
+ XFS_BMAPI_PREALLOC, 0);
break;
case XFS_IOC_UNRESVSP:
case XFS_IOC_UNRESVSP64:
@@ -716,7 +716,7 @@ xfs_ioc_space(
flags |= XFS_PREALLOC_CLEAR;
if (bf->l_start > XFS_ISIZE(ip)) {
error = xfs_alloc_file_space(ip, XFS_ISIZE(ip),
- bf->l_start - XFS_ISIZE(ip), 0);
+ bf->l_start - XFS_ISIZE(ip), 0, 0);
if (error)
goto out_unlock;
}
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 469c9fa4c178..174ef95453f5 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1186,9 +1186,10 @@ xfs_diflags_to_iflags(
struct xfs_inode *ip)
{
uint16_t flags = ip->i_d.di_flags;
+ uint64_t flags2 = ip->i_d.di_flags2;

inode->i_flags &= ~(S_IMMUTABLE | S_APPEND | S_SYNC |
- S_NOATIME | S_DAX);
+ S_NOATIME | S_DAX | S_IOMAP_IMMUTABLE);

if (flags & XFS_DIFLAG_IMMUTABLE)
inode->i_flags |= S_IMMUTABLE;
@@ -1201,9 +1202,10 @@ xfs_diflags_to_iflags(
if (S_ISREG(inode->i_mode) &&
ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
!xfs_is_reflink_inode(ip) &&
- (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
- ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
+ (ip->i_mount->m_flags & XFS_MOUNT_DAX || flags2 & XFS_DIFLAG2_DAX))
inode->i_flags |= S_DAX;
+ if (flags2 & XFS_DIFLAG2_IOMAP_IMMUTABLE)
+ inode->i_flags |= S_IOMAP_IMMUTABLE;
}

/*