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author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-03 09:11:21 -0700 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-03 09:11:21 -0700 |
commit | 3172725814f9a689d6e8b3c7979b66403abf5dae (patch) | |
tree | 6372a73150404f3390969f48433c1d978c580d4a /fs/xfs/libxfs | |
parent | f997ee2137175f5b2bd7ced52acf1ca51f04f420 (diff) | |
download | blackbird-op-linux-3172725814f9a689d6e8b3c7979b66403abf5dae.tar.gz blackbird-op-linux-3172725814f9a689d6e8b3c7979b66403abf5dae.zip |
xfs: adjust refcount of an extent of blocks in refcount btree
Provide functions to adjust the reference counts for an extent of
physical blocks stored in the refcount btree.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r-- | fs/xfs/libxfs/xfs_refcount.c | 814 |
1 files changed, 814 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c index de1340652933..f522fe130a16 100644 --- a/fs/xfs/libxfs/xfs_refcount.c +++ b/fs/xfs/libxfs/xfs_refcount.c @@ -37,6 +37,12 @@ #include "xfs_bit.h" #include "xfs_refcount.h" +/* Allowable refcount adjustment amounts. */ +enum xfs_refc_adjust_op { + XFS_REFCOUNT_ADJUST_INCREASE = 1, + XFS_REFCOUNT_ADJUST_DECREASE = -1, +}; + /* * Look up the first record less than or equal to [bno, len] in the btree * given by cur. @@ -175,3 +181,811 @@ out_error: cur->bc_private.a.agno, error, _RET_IP_); return error; } + +/* + * Adjusting the Reference Count + * + * As stated elsewhere, the reference count btree (refcbt) stores + * >1 reference counts for extents of physical blocks. In this + * operation, we're either raising or lowering the reference count of + * some subrange stored in the tree: + * + * <------ adjustment range ------> + * ----+ +---+-----+ +--+--------+--------- + * 2 | | 3 | 4 | |17| 55 | 10 + * ----+ +---+-----+ +--+--------+--------- + * X axis is physical blocks number; + * reference counts are the numbers inside the rectangles + * + * The first thing we need to do is to ensure that there are no + * refcount extents crossing either boundary of the range to be + * adjusted. For any extent that does cross a boundary, split it into + * two extents so that we can increment the refcount of one of the + * pieces later: + * + * <------ adjustment range ------> + * ----+ +---+-----+ +--+--------+----+---- + * 2 | | 3 | 2 | |17| 55 | 10 | 10 + * ----+ +---+-----+ +--+--------+----+---- + * + * For this next step, let's assume that all the physical blocks in + * the adjustment range are mapped to a file and are therefore in use + * at least once. Therefore, we can infer that any gap in the + * refcount tree within the adjustment range represents a physical + * extent with refcount == 1: + * + * <------ adjustment range ------> + * ----+---+---+-----+-+--+--------+----+---- + * 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10 + * ----+---+---+-----+-+--+--------+----+---- + * ^ + * + * For each extent that falls within the interval range, figure out + * which extent is to the left or the right of that extent. Now we + * have a left, current, and right extent. If the new reference count + * of the center extent enables us to merge left, center, and right + * into one record covering all three, do so. If the center extent is + * at the left end of the range, abuts the left extent, and its new + * reference count matches the left extent's record, then merge them. + * If the center extent is at the right end of the range, abuts the + * right extent, and the reference counts match, merge those. In the + * example, we can left merge (assuming an increment operation): + * + * <------ adjustment range ------> + * --------+---+-----+-+--+--------+----+---- + * 2 | 3 | 2 |1|17| 55 | 10 | 10 + * --------+---+-----+-+--+--------+----+---- + * ^ + * + * For all other extents within the range, adjust the reference count + * or delete it if the refcount falls below 2. If we were + * incrementing, the end result looks like this: + * + * <------ adjustment range ------> + * --------+---+-----+-+--+--------+----+---- + * 2 | 4 | 3 |2|18| 56 | 11 | 10 + * --------+---+-----+-+--+--------+----+---- + * + * The result of a decrement operation looks as such: + * + * <------ adjustment range ------> + * ----+ +---+ +--+--------+----+---- + * 2 | | 2 | |16| 54 | 9 | 10 + * ----+ +---+ +--+--------+----+---- + * DDDD 111111DD + * + * The blocks marked "D" are freed; the blocks marked "1" are only + * referenced once and therefore the record is removed from the + * refcount btree. + */ + +/* Next block after this extent. */ +static inline xfs_agblock_t +xfs_refc_next( + struct xfs_refcount_irec *rc) +{ + return rc->rc_startblock + rc->rc_blockcount; +} + +/* + * Split a refcount extent that crosses agbno. + */ +STATIC int +xfs_refcount_split_extent( + struct xfs_btree_cur *cur, + xfs_agblock_t agbno, + bool *shape_changed) +{ + struct xfs_refcount_irec rcext, tmp; + int found_rec; + int error; + + *shape_changed = false; + error = xfs_refcount_lookup_le(cur, agbno, &found_rec); + if (error) + goto out_error; + if (!found_rec) + return 0; + + error = xfs_refcount_get_rec(cur, &rcext, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno) + return 0; + + *shape_changed = true; + trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_private.a.agno, + &rcext, agbno); + + /* Establish the right extent. */ + tmp = rcext; + tmp.rc_startblock = agbno; + tmp.rc_blockcount -= (agbno - rcext.rc_startblock); + error = xfs_refcount_update(cur, &tmp); + if (error) + goto out_error; + + /* Insert the left extent. */ + tmp = rcext; + tmp.rc_blockcount = agbno - rcext.rc_startblock; + error = xfs_refcount_insert(cur, &tmp, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + return error; + +out_error: + trace_xfs_refcount_split_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Merge the left, center, and right extents. + */ +STATIC int +xfs_refcount_merge_center_extents( + struct xfs_btree_cur *cur, + struct xfs_refcount_irec *left, + struct xfs_refcount_irec *center, + struct xfs_refcount_irec *right, + unsigned long long extlen, + xfs_agblock_t *agbno, + xfs_extlen_t *aglen) +{ + int error; + int found_rec; + + trace_xfs_refcount_merge_center_extents(cur->bc_mp, + cur->bc_private.a.agno, left, center, right); + + /* + * Make sure the center and right extents are not in the btree. + * If the center extent was synthesized, the first delete call + * removes the right extent and we skip the second deletion. + * If center and right were in the btree, then the first delete + * call removes the center and the second one removes the right + * extent. + */ + error = xfs_refcount_lookup_ge(cur, center->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + error = xfs_refcount_delete(cur, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + if (center->rc_refcount > 1) { + error = xfs_refcount_delete(cur, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + } + + /* Enlarge the left extent. */ + error = xfs_refcount_lookup_le(cur, left->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + left->rc_blockcount = extlen; + error = xfs_refcount_update(cur, left); + if (error) + goto out_error; + + *aglen = 0; + return error; + +out_error: + trace_xfs_refcount_merge_center_extents_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Merge with the left extent. + */ +STATIC int +xfs_refcount_merge_left_extent( + struct xfs_btree_cur *cur, + struct xfs_refcount_irec *left, + struct xfs_refcount_irec *cleft, + xfs_agblock_t *agbno, + xfs_extlen_t *aglen) +{ + int error; + int found_rec; + + trace_xfs_refcount_merge_left_extent(cur->bc_mp, + cur->bc_private.a.agno, left, cleft); + + /* If the extent at agbno (cleft) wasn't synthesized, remove it. */ + if (cleft->rc_refcount > 1) { + error = xfs_refcount_lookup_le(cur, cleft->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + + error = xfs_refcount_delete(cur, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + } + + /* Enlarge the left extent. */ + error = xfs_refcount_lookup_le(cur, left->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + left->rc_blockcount += cleft->rc_blockcount; + error = xfs_refcount_update(cur, left); + if (error) + goto out_error; + + *agbno += cleft->rc_blockcount; + *aglen -= cleft->rc_blockcount; + return error; + +out_error: + trace_xfs_refcount_merge_left_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Merge with the right extent. + */ +STATIC int +xfs_refcount_merge_right_extent( + struct xfs_btree_cur *cur, + struct xfs_refcount_irec *right, + struct xfs_refcount_irec *cright, + xfs_agblock_t *agbno, + xfs_extlen_t *aglen) +{ + int error; + int found_rec; + + trace_xfs_refcount_merge_right_extent(cur->bc_mp, + cur->bc_private.a.agno, cright, right); + + /* + * If the extent ending at agbno+aglen (cright) wasn't synthesized, + * remove it. + */ + if (cright->rc_refcount > 1) { + error = xfs_refcount_lookup_le(cur, cright->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + + error = xfs_refcount_delete(cur, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + } + + /* Enlarge the right extent. */ + error = xfs_refcount_lookup_le(cur, right->rc_startblock, + &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + right->rc_startblock -= cright->rc_blockcount; + right->rc_blockcount += cright->rc_blockcount; + error = xfs_refcount_update(cur, right); + if (error) + goto out_error; + + *aglen -= cright->rc_blockcount; + return error; + +out_error: + trace_xfs_refcount_merge_right_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Find the left extent and the one after it (cleft). This function assumes + * that we've already split any extent crossing agbno. + */ +STATIC int +xfs_refcount_find_left_extents( + struct xfs_btree_cur *cur, + struct xfs_refcount_irec *left, + struct xfs_refcount_irec *cleft, + xfs_agblock_t agbno, + xfs_extlen_t aglen) +{ + struct xfs_refcount_irec tmp; + int error; + int found_rec; + + left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK; + error = xfs_refcount_lookup_le(cur, agbno - 1, &found_rec); + if (error) + goto out_error; + if (!found_rec) + return 0; + + error = xfs_refcount_get_rec(cur, &tmp, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + if (xfs_refc_next(&tmp) != agbno) + return 0; + /* We have a left extent; retrieve (or invent) the next right one */ + *left = tmp; + + error = xfs_btree_increment(cur, 0, &found_rec); + if (error) + goto out_error; + if (found_rec) { + error = xfs_refcount_get_rec(cur, &tmp, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + + /* if tmp starts at the end of our range, just use that */ + if (tmp.rc_startblock == agbno) + *cleft = tmp; + else { + /* + * There's a gap in the refcntbt at the start of the + * range we're interested in (refcount == 1) so + * synthesize the implied extent and pass it back. + * We assume here that the agbno/aglen range was + * passed in from a data fork extent mapping and + * therefore is allocated to exactly one owner. + */ + cleft->rc_startblock = agbno; + cleft->rc_blockcount = min(aglen, + tmp.rc_startblock - agbno); + cleft->rc_refcount = 1; + } + } else { + /* + * No extents, so pretend that there's one covering the whole + * range. + */ + cleft->rc_startblock = agbno; + cleft->rc_blockcount = aglen; + cleft->rc_refcount = 1; + } + trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_private.a.agno, + left, cleft, agbno); + return error; + +out_error: + trace_xfs_refcount_find_left_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* + * Find the right extent and the one before it (cright). This function + * assumes that we've already split any extents crossing agbno + aglen. + */ +STATIC int +xfs_refcount_find_right_extents( + struct xfs_btree_cur *cur, + struct xfs_refcount_irec *right, + struct xfs_refcount_irec *cright, + xfs_agblock_t agbno, + xfs_extlen_t aglen) +{ + struct xfs_refcount_irec tmp; + int error; + int found_rec; + + right->rc_startblock = cright->rc_startblock = NULLAGBLOCK; + error = xfs_refcount_lookup_ge(cur, agbno + aglen, &found_rec); + if (error) + goto out_error; + if (!found_rec) + return 0; + + error = xfs_refcount_get_rec(cur, &tmp, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); + + if (tmp.rc_startblock != agbno + aglen) + return 0; + /* We have a right extent; retrieve (or invent) the next left one */ + *right = tmp; + + error = xfs_btree_decrement(cur, 0, &found_rec); + if (error) + goto out_error; + if (found_rec) { + error = xfs_refcount_get_rec(cur, &tmp, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, + out_error); + + /* if tmp ends at the end of our range, just use that */ + if (xfs_refc_next(&tmp) == agbno + aglen) + *cright = tmp; + else { + /* + * There's a gap in the refcntbt at the end of the + * range we're interested in (refcount == 1) so + * create the implied extent and pass it back. + * We assume here that the agbno/aglen range was + * passed in from a data fork extent mapping and + * therefore is allocated to exactly one owner. + */ + cright->rc_startblock = max(agbno, xfs_refc_next(&tmp)); + cright->rc_blockcount = right->rc_startblock - + cright->rc_startblock; + cright->rc_refcount = 1; + } + } else { + /* + * No extents, so pretend that there's one covering the whole + * range. + */ + cright->rc_startblock = agbno; + cright->rc_blockcount = aglen; + cright->rc_refcount = 1; + } + trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_private.a.agno, + cright, right, agbno + aglen); + return error; + +out_error: + trace_xfs_refcount_find_right_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* Is this extent valid? */ +static inline bool +xfs_refc_valid( + struct xfs_refcount_irec *rc) +{ + return rc->rc_startblock != NULLAGBLOCK; +} + +/* + * Try to merge with any extents on the boundaries of the adjustment range. + */ +STATIC int +xfs_refcount_merge_extents( + struct xfs_btree_cur *cur, + xfs_agblock_t *agbno, + xfs_extlen_t *aglen, + enum xfs_refc_adjust_op adjust, + bool *shape_changed) +{ + struct xfs_refcount_irec left = {0}, cleft = {0}; + struct xfs_refcount_irec cright = {0}, right = {0}; + int error; + unsigned long long ulen; + bool cequal; + + *shape_changed = false; + /* + * Find the extent just below agbno [left], just above agbno [cleft], + * just below (agbno + aglen) [cright], and just above (agbno + aglen) + * [right]. + */ + error = xfs_refcount_find_left_extents(cur, &left, &cleft, *agbno, + *aglen); + if (error) + return error; + error = xfs_refcount_find_right_extents(cur, &right, &cright, *agbno, + *aglen); + if (error) + return error; + + /* No left or right extent to merge; exit. */ + if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right)) + return 0; + + cequal = (cleft.rc_startblock == cright.rc_startblock) && + (cleft.rc_blockcount == cright.rc_blockcount); + + /* Try to merge left, cleft, and right. cleft must == cright. */ + ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount + + right.rc_blockcount; + if (xfs_refc_valid(&left) && xfs_refc_valid(&right) && + xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal && + left.rc_refcount == cleft.rc_refcount + adjust && + right.rc_refcount == cleft.rc_refcount + adjust && + ulen < MAXREFCEXTLEN) { + *shape_changed = true; + return xfs_refcount_merge_center_extents(cur, &left, &cleft, + &right, ulen, agbno, aglen); + } + + /* Try to merge left and cleft. */ + ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount; + if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) && + left.rc_refcount == cleft.rc_refcount + adjust && + ulen < MAXREFCEXTLEN) { + *shape_changed = true; + error = xfs_refcount_merge_left_extent(cur, &left, &cleft, + agbno, aglen); + if (error) + return error; + + /* + * If we just merged left + cleft and cleft == cright, + * we no longer have a cright to merge with right. We're done. + */ + if (cequal) + return 0; + } + + /* Try to merge cright and right. */ + ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount; + if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) && + right.rc_refcount == cright.rc_refcount + adjust && + ulen < MAXREFCEXTLEN) { + *shape_changed = true; + return xfs_refcount_merge_right_extent(cur, &right, &cright, + agbno, aglen); + } + + return error; +} + +/* + * While we're adjusting the refcounts records of an extent, we have + * to keep an eye on the number of extents we're dirtying -- run too + * many in a single transaction and we'll exceed the transaction's + * reservation and crash the fs. Each record adds 12 bytes to the + * log (plus any key updates) so we'll conservatively assume 24 bytes + * per record. We must also leave space for btree splits on both ends + * of the range and space for the CUD and a new CUI. + * + * XXX: This is a pretty hand-wavy estimate. The penalty for guessing + * true incorrectly is a shutdown FS; the penalty for guessing false + * incorrectly is more transaction rolls than might be necessary. + * Be conservative here. + */ +static bool +xfs_refcount_still_have_space( + struct xfs_btree_cur *cur) +{ + unsigned long overhead; + + overhead = cur->bc_private.a.priv.refc.shape_changes * + xfs_allocfree_log_count(cur->bc_mp, 1); + overhead *= cur->bc_mp->m_sb.sb_blocksize; + + /* + * Only allow 2 refcount extent updates per transaction if the + * refcount continue update "error" has been injected. + */ + if (cur->bc_private.a.priv.refc.nr_ops > 2 && + XFS_TEST_ERROR(false, cur->bc_mp, + XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE, + XFS_RANDOM_REFCOUNT_CONTINUE_UPDATE)) + return false; + + if (cur->bc_private.a.priv.refc.nr_ops == 0) + return true; + else if (overhead > cur->bc_tp->t_log_res) + return false; + return cur->bc_tp->t_log_res - overhead > + cur->bc_private.a.priv.refc.nr_ops * 32; +} + +/* + * Adjust the refcounts of middle extents. At this point we should have + * split extents that crossed the adjustment range; merged with adjacent + * extents; and updated agbno/aglen to reflect the merges. Therefore, + * all we have to do is update the extents inside [agbno, agbno + aglen]. + */ +STATIC int +xfs_refcount_adjust_extents( + struct xfs_btree_cur *cur, + xfs_agblock_t *agbno, + xfs_extlen_t *aglen, + enum xfs_refc_adjust_op adj, + struct xfs_defer_ops *dfops, + struct xfs_owner_info *oinfo) +{ + struct xfs_refcount_irec ext, tmp; + int error; + int found_rec, found_tmp; + xfs_fsblock_t fsbno; + + /* Merging did all the work already. */ + if (*aglen == 0) + return 0; + + error = xfs_refcount_lookup_ge(cur, *agbno, &found_rec); + if (error) + goto out_error; + + while (*aglen > 0 && xfs_refcount_still_have_space(cur)) { + error = xfs_refcount_get_rec(cur, &ext, &found_rec); + if (error) + goto out_error; + if (!found_rec) { + ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks; + ext.rc_blockcount = 0; + ext.rc_refcount = 0; + } + + /* + * Deal with a hole in the refcount tree; if a file maps to + * these blocks and there's no refcountbt record, pretend that + * there is one with refcount == 1. + */ + if (ext.rc_startblock != *agbno) { + tmp.rc_startblock = *agbno; + tmp.rc_blockcount = min(*aglen, + ext.rc_startblock - *agbno); + tmp.rc_refcount = 1 + adj; + trace_xfs_refcount_modify_extent(cur->bc_mp, + cur->bc_private.a.agno, &tmp); + + /* + * Either cover the hole (increment) or + * delete the range (decrement). + */ + if (tmp.rc_refcount) { + error = xfs_refcount_insert(cur, &tmp, + &found_tmp); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, + found_tmp == 1, out_error); + cur->bc_private.a.priv.refc.nr_ops++; + } else { + fsbno = XFS_AGB_TO_FSB(cur->bc_mp, + cur->bc_private.a.agno, + tmp.rc_startblock); + xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, + tmp.rc_blockcount, oinfo); + } + + (*agbno) += tmp.rc_blockcount; + (*aglen) -= tmp.rc_blockcount; + + error = xfs_refcount_lookup_ge(cur, *agbno, + &found_rec); + if (error) + goto out_error; + } + + /* Stop if there's nothing left to modify */ + if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) + break; + + /* + * Adjust the reference count and either update the tree + * (incr) or free the blocks (decr). + */ + if (ext.rc_refcount == MAXREFCOUNT) + goto skip; + ext.rc_refcount += adj; + trace_xfs_refcount_modify_extent(cur->bc_mp, + cur->bc_private.a.agno, &ext); + if (ext.rc_refcount > 1) { + error = xfs_refcount_update(cur, &ext); + if (error) + goto out_error; + cur->bc_private.a.priv.refc.nr_ops++; + } else if (ext.rc_refcount == 1) { + error = xfs_refcount_delete(cur, &found_rec); + if (error) + goto out_error; + XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, + found_rec == 1, out_error); + cur->bc_private.a.priv.refc.nr_ops++; + goto advloop; + } else { + fsbno = XFS_AGB_TO_FSB(cur->bc_mp, + cur->bc_private.a.agno, + ext.rc_startblock); + xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, + ext.rc_blockcount, oinfo); + } + +skip: + error = xfs_btree_increment(cur, 0, &found_rec); + if (error) + goto out_error; + +advloop: + (*agbno) += ext.rc_blockcount; + (*aglen) -= ext.rc_blockcount; + } + + return error; +out_error: + trace_xfs_refcount_modify_extent_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +/* Adjust the reference count of a range of AG blocks. */ +STATIC int +xfs_refcount_adjust( + struct xfs_btree_cur *cur, + xfs_agblock_t agbno, + xfs_extlen_t aglen, + xfs_agblock_t *new_agbno, + xfs_extlen_t *new_aglen, + enum xfs_refc_adjust_op adj, + struct xfs_defer_ops *dfops, + struct xfs_owner_info *oinfo) +{ + bool shape_changed; + int shape_changes = 0; + int error; + + *new_agbno = agbno; + *new_aglen = aglen; + if (adj == XFS_REFCOUNT_ADJUST_INCREASE) + trace_xfs_refcount_increase(cur->bc_mp, cur->bc_private.a.agno, + agbno, aglen); + else + trace_xfs_refcount_decrease(cur->bc_mp, cur->bc_private.a.agno, + agbno, aglen); + + /* + * Ensure that no rcextents cross the boundary of the adjustment range. + */ + error = xfs_refcount_split_extent(cur, agbno, &shape_changed); + if (error) + goto out_error; + if (shape_changed) + shape_changes++; + + error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); + if (error) + goto out_error; + if (shape_changed) + shape_changes++; + + /* + * Try to merge with the left or right extents of the range. + */ + error = xfs_refcount_merge_extents(cur, new_agbno, new_aglen, adj, + &shape_changed); + if (error) + goto out_error; + if (shape_changed) + shape_changes++; + if (shape_changes) + cur->bc_private.a.priv.refc.shape_changes++; + + /* Now that we've taken care of the ends, adjust the middle extents */ + error = xfs_refcount_adjust_extents(cur, new_agbno, new_aglen, + adj, dfops, oinfo); + if (error) + goto out_error; + + return 0; + +out_error: + trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_private.a.agno, + error, _RET_IP_); + return error; +} |