diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_alloc.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 0b3b4ace3915..e67a1f23f318 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -3652,3 +3652,91 @@ xfs_extfree_intent_destroy_cache(void) kmem_cache_destroy(xfs_extfree_item_cache); xfs_extfree_item_cache = NULL; } + +/* + * Find the next chunk of free space in @pag starting at @agbno and going no + * higher than @end_agbno. Set @agbno and @len to whatever free space we find, + * or to @end_agbno if we find no space. + */ +int +xfs_alloc_find_freesp( + struct xfs_trans *tp, + struct xfs_perag *pag, + xfs_agblock_t *agbno, + xfs_agblock_t end_agbno, + xfs_extlen_t *len) +{ + struct xfs_mount *mp = pag->pag_mount; + struct xfs_btree_cur *cur; + struct xfs_buf *agf_bp = NULL; + xfs_agblock_t found_agbno; + xfs_extlen_t found_len; + int found; + int error; + + trace_xfs_alloc_find_freesp(mp, pag->pag_agno, *agbno, + end_agbno - *agbno); + + error = xfs_alloc_read_agf(pag, tp, 0, &agf_bp); + if (error) + return error; + + cur = xfs_allocbt_init_cursor(mp, tp, agf_bp, pag, XFS_BTNUM_BNO); + + /* Try to find a free extent that starts before here. */ + error = xfs_alloc_lookup_le(cur, *agbno, 0, &found); + if (error) + goto out_cur; + if (found) { + error = xfs_alloc_get_rec(cur, &found_agbno, &found_len, + &found); + if (error) + goto out_cur; + if (XFS_IS_CORRUPT(mp, !found)) { + xfs_btree_mark_sick(cur); + error = -EFSCORRUPTED; + goto out_cur; + } + + if (found_agbno + found_len > *agbno) + goto found; + } + + /* Examine the next record if free extent not in range. */ + error = xfs_btree_increment(cur, 0, &found); + if (error) + goto out_cur; + if (!found) + goto next_ag; + + error = xfs_alloc_get_rec(cur, &found_agbno, &found_len, &found); + if (error) + goto out_cur; + if (XFS_IS_CORRUPT(mp, !found)) { + xfs_btree_mark_sick(cur); + error = -EFSCORRUPTED; + goto out_cur; + } + + if (found_agbno >= end_agbno) + goto next_ag; + +found: + /* Found something, so update the mapping. */ + trace_xfs_alloc_find_freesp_done(mp, pag->pag_agno, found_agbno, + found_len); + if (found_agbno < *agbno) { + found_len -= *agbno - found_agbno; + found_agbno = *agbno; + } + *len = found_len; + *agbno = found_agbno; + goto out_cur; +next_ag: + /* Found nothing, so advance the cursor beyond the end of the range. */ + *agbno = end_agbno; + *len = 0; +out_cur: + xfs_btree_del_cursor(cur, error); + return error; +} |