diff options
author | Darrick J. Wong | 2016-08-03 11:45:12 +1000 |
---|---|---|
committer | Dave Chinner | 2016-08-03 11:45:12 +1000 |
commit | f922cd90b82c5e78a860f194728d4dadc8575106 (patch) | |
tree | 6b07a1e06c9435ecb87d5e1de70b746187cd3a59 | |
parent | 0a1b0b3855cf74bb11243076b00178a0f1a0320e (diff) |
xfs: remove an extent from the rmap btree
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>
-rw-r--r-- | fs/xfs/libxfs/xfs_rmap.c | 220 |
1 files changed, 215 insertions, 5 deletions
diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c index 1c0e2a8943a4..1e48a0b62ba6 100644 --- a/fs/xfs/libxfs/xfs_rmap.c +++ b/fs/xfs/libxfs/xfs_rmap.c @@ -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, <rec, &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, <rec); + 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, <rec); + 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, <rec); + 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; } |