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xfs: separate function to check if inode shares extents 

Separate the "clear reflink flag" function into one function that checks
if the flag is needed, and a second function that checks and clears the
flag.  The inode scrub code will want to check the necessity of the flag
without clearing it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2017-06-16 11:00:11 -07:00
parent 92ff7285f1
commit ea7cdd7b7b
2 changed files with 58 additions and 40 deletions
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96
fs/xfs/xfs_reflink.c
View File

@ -1406,56 +1406,72 @@ xfs_reflink_dirty_extents(
return error;
}
/* Does this inode need the reflink flag? */
int
xfs_reflink_inode_has_shared_extents(
struct xfs_trans *tp,
struct xfs_inode *ip,
bool *has_shared)
{
struct xfs_bmbt_irec got;
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t aglen;
xfs_agblock_t rbno;
xfs_extlen_t rlen;
xfs_extnum_t idx;
bool found;
int error;
ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
if (error)
return error;
}
*has_shared = false;
found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &got);
while (found) {
if (isnullstartblock(got.br_startblock) ||
got.br_state != XFS_EXT_NORM)
goto next;
agno = XFS_FSB_TO_AGNO(mp, got.br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, got.br_startblock);
aglen = got.br_blockcount;
error = xfs_reflink_find_shared(mp, tp, agno, agbno, aglen,
&rbno, &rlen, false);
if (error)
return error;
/* Is there still a shared block here? */
if (rbno != NULLAGBLOCK) {
*has_shared = true;
return 0;
}
next:
found = xfs_iext_get_extent(ifp, ++idx, &got);
}
return 0;
}
/* Clear the inode reflink flag if there are no shared extents. */
int
xfs_reflink_clear_inode_flag(
struct xfs_inode *ip,
struct xfs_trans **tpp)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t fbno;
xfs_filblks_t end;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t aglen;
xfs_agblock_t rbno;
xfs_extlen_t rlen;
struct xfs_bmbt_irec map;
int nmaps;
bool needs_flag;
int error = 0;
ASSERT(xfs_is_reflink_inode(ip));
fbno = 0;
end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip)));
while (end - fbno > 0) {
nmaps = 1;
/*
* Look for extents in the file. Skip holes, delalloc, or
* unwritten extents; they can't be reflinked.
*/
error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0);
if (error)
return error;
if (nmaps == 0)
break;
if (!xfs_bmap_is_real_extent(&map))
goto next;
agno = XFS_FSB_TO_AGNO(mp, map.br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock);
aglen = map.br_blockcount;
error = xfs_reflink_find_shared(mp, *tpp, agno, agbno, aglen,
&rbno, &rlen, false);
if (error)
return error;
/* Is there still a shared block here? */
if (rbno != NULLAGBLOCK)
return 0;
next:
fbno = map.br_startoff + map.br_blockcount;
}
error = xfs_reflink_inode_has_shared_extents(*tpp, ip, &needs_flag);
if (error || needs_flag)
return error;
/*
* We didn't find any shared blocks so turn off the reflink flag.

2
fs/xfs/xfs_reflink.h
View File

@ -47,6 +47,8 @@ extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out, u64 len, bool is_dedupe);
extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,
struct xfs_inode *ip, bool *has_shared);
extern int xfs_reflink_clear_inode_flag(struct xfs_inode *ip,
struct xfs_trans **tpp);
extern int xfs_reflink_unshare(struct xfs_inode *ip, xfs_off_t offset,