On Saturday 10 October 2020 11:04:34 PM IST Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> In commit fe341eb151ec, I forgot that xfs_free_file_space isn't strictly
> a "remove mapped blocks" function. It is actually a function to zero
> file space by punching out the middle and writing zeroes to the
> unaligned ends of the specified range. Therefore, putting a rtextsize
> alignment check in that function is wrong because that breaks unaligned
> ZERO_RANGE on the realtime volume.
>
> Furthermore, xfs_file_fallocate already has alignment checks for the
> functions require the file range to be aligned to the size of a
> fundamental allocation unit (which is 1 FSB on the data volume and 1 rt
> extent on the realtime volume). Create a new helper to return the
> desired allocation unit size, fix the fallocate frontend to use it,
> fix free_file_space to delete the correct range, and remove a now
> redundant check from insert_file_space.
>
The changes look good to me.
Reviewed-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
> Fixes: fe341eb151ec ("xfs: ensure that fpunch, fcollapse, and finsert operations are aligned to rt extent size")
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/xfs_bmap_util.c | 17 ++++-------------
> fs/xfs/xfs_file.c | 10 ++++------
> fs/xfs/xfs_inode.c | 13 +++++++++++++
> fs/xfs/xfs_inode.h | 1 +
> 4 files changed, 22 insertions(+), 19 deletions(-)
>
>
> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
> index f2a8a0e75e1f..52cddcfee8a1 100644
> --- a/fs/xfs/xfs_bmap_util.c
> +++ b/fs/xfs/xfs_bmap_util.c
> @@ -947,11 +947,10 @@ xfs_free_file_space(
> endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
>
> /* We can only free complete realtime extents. */
> - if (XFS_IS_REALTIME_INODE(ip)) {
> - xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
> -
> - if ((startoffset_fsb | endoffset_fsb) & (extsz - 1))
> - return -EINVAL;
> + if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 0) {
> + startoffset_fsb = round_up(startoffset_fsb,
> + mp->m_sb.sb_rextsize);
> + endoffset_fsb = round_down(endoffset_fsb, mp->m_sb.sb_rextsize);
> }
>
> /*
> @@ -1147,14 +1146,6 @@ xfs_insert_file_space(
>
> trace_xfs_insert_file_space(ip);
>
> - /* We can only insert complete realtime extents. */
> - if (XFS_IS_REALTIME_INODE(ip)) {
> - xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
> -
> - if ((stop_fsb | shift_fsb) & (extsz - 1))
> - return -EINVAL;
> - }
> -
> error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
> if (error)
> return error;
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 3d1b95124744..e9b4b1dada75 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -803,6 +803,8 @@ xfs_file_fallocate(
> enum xfs_prealloc_flags flags = 0;
> uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
> loff_t new_size = 0;
> + unsigned int blksize = xfs_inode_alloc_blocksize(ip);
> + unsigned int blkmask = blksize - 1;
> bool do_file_insert = false;
>
> if (!S_ISREG(inode->i_mode))
> @@ -850,9 +852,7 @@ xfs_file_fallocate(
> if (error)
> goto out_unlock;
> } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
> - unsigned int blksize_mask = i_blocksize(inode) - 1;
> -
> - if (offset & blksize_mask || len & blksize_mask) {
> + if ((offset | len) & blkmask) {
> error = -EINVAL;
> goto out_unlock;
> }
> @@ -872,10 +872,9 @@ xfs_file_fallocate(
> if (error)
> goto out_unlock;
> } else if (mode & FALLOC_FL_INSERT_RANGE) {
> - unsigned int blksize_mask = i_blocksize(inode) - 1;
> loff_t isize = i_size_read(inode);
>
> - if (offset & blksize_mask || len & blksize_mask) {
> + if ((offset | len) & blkmask) {
> error = -EINVAL;
> goto out_unlock;
> }
> @@ -917,7 +916,6 @@ xfs_file_fallocate(
> * 2.) If prealloc returns ENOSPC, the file range is
> * still zero-valued by virtue of the hole punch.
> */
> - unsigned int blksize = i_blocksize(inode);
>
> trace_xfs_zero_file_space(ip);
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 2bfbcf28b1bd..20bb5fae0d00 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -3813,3 +3813,16 @@ xfs_iunlock2_io_mmap(
> if (!same_inode)
> inode_unlock(VFS_I(ip1));
> }
> +
> +/* Returns the size of fundamental allocation unit for a file, in bytes. */
> +unsigned int
> +xfs_inode_alloc_blocksize(
> + struct xfs_inode *ip)
> +{
> + unsigned int blocks = 1;
> +
> + if (XFS_IS_REALTIME_INODE(ip))
> + blocks = ip->i_mount->m_sb.sb_rextsize;
> +
> + return XFS_FSB_TO_B(ip->i_mount, blocks);
> +}
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index 751a3d1d7d84..270b35d9dcb0 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -475,5 +475,6 @@ void xfs_end_io(struct work_struct *work);
>
> int xfs_ilock2_io_mmap(struct xfs_inode *ip1, struct xfs_inode *ip2);
> void xfs_iunlock2_io_mmap(struct xfs_inode *ip1, struct xfs_inode *ip2);
> +unsigned int xfs_inode_alloc_blocksize(struct xfs_inode *ip);
>
> #endif /* __XFS_INODE_H__ */
>
>
--
chandan
