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

Darrick J. Wong
2017-07-31T17:13:13Z

On Sat, Jul 29, 2017 at 12:43:46PM -0700, Dan Williams wrote:
> 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;

Can we set the inode flag in xfs_seal_file_space instead of plumbing
di_flags2 all over the place into the bmap routines?

Also, what does

xfs_alloc_file_space(..., XFS_BMAPI_ATTRFORK, XFS_DIFLAG2_REFLINK);

mean? :)

--D

> + }
> +
> 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;
> }
>
> /*
>
> --
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