Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-24 05:02:12 +00:00
Code Issues Packages Projects Releases Wiki Activity

xfs: remove an extent from the rmap btree

Browse Source 
Originally-From: Dave Chinner <dchinner@redhat.com>

Now that we have records in the rmap btree, we need to remove them
when extents are freed. This needs to find the relevant record in
the btree and remove/trim/split it accordingly.

[darrick.wong@oracle.com: make rmap routines handle the enlarged keyspace]
[dchinner: remove remaining unused debug printks]
[darrick: fix a bug when growfs in an AG with an rmap ending at EOFS]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Darrick J. Wong 2016-08-03 11:45:12 +10:00 committed by Dave Chinner
parent 0a1b0b3855
commit f922cd90b8
1 changed files with 215 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

220
fs/xfs/libxfs/xfs_rmap.c
View File

@ -133,6 +133,212 @@ xfs_rmap_get_rec(
return xfs_rmap_btrec_to_irec(rec, irec);
}
/*
* Find the extent in the rmap btree and remove it.
*
* The record we find should always be an exact match for the extent that we're
* looking for, since we insert them into the btree without modification.
*
* Special Case #1: when growing the filesystem, we "free" an extent when
* growing the last AG. This extent is new space and so it is not tracked as
* used space in the btree. The growfs code will pass in an owner of
* XFS_RMAP_OWN_NULL to indicate that it expected that there is no owner of this
* extent. We verify that - the extent lookup result in a record that does not
* overlap.
*
* Special Case #2: EFIs do not record the owner of the extent, so when
* recovering EFIs from the log we pass in XFS_RMAP_OWN_UNKNOWN to tell the rmap
* btree to ignore the owner (i.e. wildcard match) so we don't trigger
* corruption checks during log recovery.
*/
STATIC int
xfs_rmap_unmap(
struct xfs_btree_cur *cur,
xfs_agblock_t bno,
xfs_extlen_t len,
bool unwritten,
struct xfs_owner_info *oinfo)
{
struct xfs_mount *mp = cur->bc_mp;
struct xfs_rmap_irec ltrec;
uint64_t ltoff;
int error = 0;
int i;
uint64_t owner;
uint64_t offset;
unsigned int flags;
bool ignore_off;
xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
ignore_off = XFS_RMAP_NON_INODE_OWNER(owner) ||
(flags & XFS_RMAP_BMBT_BLOCK);
if (unwritten)
flags |= XFS_RMAP_UNWRITTEN;
trace_xfs_rmap_unmap(mp, cur->bc_private.a.agno, bno, len,
unwritten, oinfo);
/*
* We should always have a left record because there's a static record
* for the AG headers at rm_startblock == 0 created by mkfs/growfs that
* will not ever be removed from the tree.
*/
error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, flags, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
error = xfs_rmap_get_rec(cur, &ltrec, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
cur->bc_private.a.agno, ltrec.rm_startblock,
ltrec.rm_blockcount, ltrec.rm_owner,
ltrec.rm_offset, ltrec.rm_flags);
ltoff = ltrec.rm_offset;
/*
* For growfs, the incoming extent must be beyond the left record we
* just found as it is new space and won't be used by anyone. This is
* just a corruption check as we don't actually do anything with this
* extent. Note that we need to use >= instead of > because it might
* be the case that the "left" extent goes all the way to EOFS.
*/
if (owner == XFS_RMAP_OWN_NULL) {
XFS_WANT_CORRUPTED_GOTO(mp, bno >= ltrec.rm_startblock +
ltrec.rm_blockcount, out_error);
goto out_done;
}
/* Make sure the unwritten flag matches. */
XFS_WANT_CORRUPTED_GOTO(mp, (flags & XFS_RMAP_UNWRITTEN) ==
(ltrec.rm_flags & XFS_RMAP_UNWRITTEN), out_error);
/* Make sure the extent we found covers the entire freeing range. */
XFS_WANT_CORRUPTED_GOTO(mp, ltrec.rm_startblock <= bno &&
ltrec.rm_startblock + ltrec.rm_blockcount >=
bno + len, out_error);
/* Make sure the owner matches what we expect to find in the tree. */
XFS_WANT_CORRUPTED_GOTO(mp, owner == ltrec.rm_owner ||
XFS_RMAP_NON_INODE_OWNER(owner), out_error);
/* Check the offset, if necessary. */
if (!XFS_RMAP_NON_INODE_OWNER(owner)) {
if (flags & XFS_RMAP_BMBT_BLOCK) {
XFS_WANT_CORRUPTED_GOTO(mp,
ltrec.rm_flags & XFS_RMAP_BMBT_BLOCK,
out_error);
} else {
XFS_WANT_CORRUPTED_GOTO(mp,
ltrec.rm_offset <= offset, out_error);
XFS_WANT_CORRUPTED_GOTO(mp,
ltoff + ltrec.rm_blockcount >= offset + len,
out_error);
}
}
if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) {
/* exact match, simply remove the record from rmap tree */
trace_xfs_rmap_delete(mp, cur->bc_private.a.agno,
ltrec.rm_startblock, ltrec.rm_blockcount,
ltrec.rm_owner, ltrec.rm_offset,
ltrec.rm_flags);
error = xfs_btree_delete(cur, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_error);
} else if (ltrec.rm_startblock == bno) {
/*
* overlap left hand side of extent: move the start, trim the
* length and update the current record.
*
* ltbno ltlen
* Orig: |oooooooooooooooooooo|
* Freeing: |fffffffff|
* Result: |rrrrrrrrrr|
* bno len
*/
ltrec.rm_startblock += len;
ltrec.rm_blockcount -= len;
if (!ignore_off)
ltrec.rm_offset += len;
error = xfs_rmap_update(cur, &ltrec);
if (error)
goto out_error;
} else if (ltrec.rm_startblock + ltrec.rm_blockcount == bno + len) {
/*
* overlap right hand side of extent: trim the length and update
* the current record.
*
* ltbno ltlen
* Orig: |oooooooooooooooooooo|
* Freeing: |fffffffff|
* Result: |rrrrrrrrrr|
* bno len
*/
ltrec.rm_blockcount -= len;
error = xfs_rmap_update(cur, &ltrec);
if (error)
goto out_error;
} else {
/*
* overlap middle of extent: trim the length of the existing
* record to the length of the new left-extent size, increment
* the insertion position so we can insert a new record
* containing the remaining right-extent space.
*
* ltbno ltlen
* Orig: |oooooooooooooooooooo|
* Freeing: |fffffffff|
* Result: |rrrrr| |rrrr|
* bno len
*/
xfs_extlen_t orig_len = ltrec.rm_blockcount;
ltrec.rm_blockcount = bno - ltrec.rm_startblock;
error = xfs_rmap_update(cur, &ltrec);
if (error)
goto out_error;
error = xfs_btree_increment(cur, 0, &i);
if (error)
goto out_error;
cur->bc_rec.r.rm_startblock = bno + len;
cur->bc_rec.r.rm_blockcount = orig_len - len -
ltrec.rm_blockcount;
cur->bc_rec.r.rm_owner = ltrec.rm_owner;
if (ignore_off)
cur->bc_rec.r.rm_offset = 0;
else
cur->bc_rec.r.rm_offset = offset + len;
cur->bc_rec.r.rm_flags = flags;
trace_xfs_rmap_insert(mp, cur->bc_private.a.agno,
cur->bc_rec.r.rm_startblock,
cur->bc_rec.r.rm_blockcount,
cur->bc_rec.r.rm_owner,
cur->bc_rec.r.rm_offset,
cur->bc_rec.r.rm_flags);
error = xfs_btree_insert(cur, &i);
if (error)
goto out_error;
}
out_done:
trace_xfs_rmap_unmap_done(mp, cur->bc_private.a.agno, bno, len,
unwritten, oinfo);
out_error:
if (error)
trace_xfs_rmap_unmap_error(mp, cur->bc_private.a.agno,
error, _RET_IP_);
return error;
}
/*
* Remove a reference to an extent in the rmap btree.
*/
int
xfs_rmap_free(
struct xfs_trans *tp,
@ -143,19 +349,23 @@ xfs_rmap_free(
struct xfs_owner_info *oinfo)
{
struct xfs_mount *mp = tp->t_mountp;
int error = 0;
struct xfs_btree_cur *cur;
int error;
if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
return 0;
trace_xfs_rmap_unmap(mp, agno, bno, len, false, oinfo);
if (1)
cur = xfs_rmapbt_init_cursor(mp, tp, agbp, agno);
error = xfs_rmap_unmap(cur, bno, len, false, oinfo);
if (error)
goto out_error;
trace_xfs_rmap_unmap_done(mp, agno, bno, len, false, oinfo);
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
out_error:
trace_xfs_rmap_unmap_error(mp, agno, error, _RET_IP_);
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}