diff options
Diffstat (limited to 'fs/xfs')
-rw-r--r-- | fs/xfs/xfs_dir2_block.c | 386 |
1 files changed, 209 insertions, 177 deletions
diff --git a/fs/xfs/xfs_dir2_block.c b/fs/xfs/xfs_dir2_block.c index 53666ca6c953..25ce409487be 100644 --- a/fs/xfs/xfs_dir2_block.c +++ b/fs/xfs/xfs_dir2_block.c @@ -56,6 +56,178 @@ xfs_dir_startup(void) xfs_dir_hash_dotdot = xfs_da_hashname((unsigned char *)"..", 2); } +static int +xfs_dir2_block_read( + struct xfs_trans *tp, + struct xfs_inode *dp, + struct xfs_buf **bpp) +{ + struct xfs_mount *mp = dp->i_mount; + + return xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, bpp, + XFS_DATA_FORK, NULL); +} + +static void +xfs_dir2_block_need_space( + struct xfs_dir2_data_hdr *hdr, + struct xfs_dir2_block_tail *btp, + struct xfs_dir2_leaf_entry *blp, + __be16 **tagpp, + struct xfs_dir2_data_unused **dupp, + struct xfs_dir2_data_unused **enddupp, + int *compact, + int len) +{ + struct xfs_dir2_data_free *bf; + __be16 *tagp = NULL; + struct xfs_dir2_data_unused *dup = NULL; + struct xfs_dir2_data_unused *enddup = NULL; + + *compact = 0; + bf = hdr->bestfree; + + /* + * If there are stale entries we'll use one for the leaf. + */ + if (btp->stale) { + if (be16_to_cpu(bf[0].length) >= len) { + /* + * The biggest entry enough to avoid compaction. + */ + dup = (xfs_dir2_data_unused_t *) + ((char *)hdr + be16_to_cpu(bf[0].offset)); + goto out; + } + + /* + * Will need to compact to make this work. + * Tag just before the first leaf entry. + */ + *compact = 1; + tagp = (__be16 *)blp - 1; + + /* Data object just before the first leaf entry. */ + dup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp)); + + /* + * If it's not free then the data will go where the + * leaf data starts now, if it works at all. + */ + if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { + if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) * + (uint)sizeof(*blp) < len) + dup = NULL; + } else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len) + dup = NULL; + else + dup = (xfs_dir2_data_unused_t *)blp; + goto out; + } + + /* + * no stale entries, so just use free space. + * Tag just before the first leaf entry. + */ + tagp = (__be16 *)blp - 1; + + /* Data object just before the first leaf entry. */ + enddup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp)); + + /* + * If it's not free then can't do this add without cleaning up: + * the space before the first leaf entry needs to be free so it + * can be expanded to hold the pointer to the new entry. + */ + if (be16_to_cpu(enddup->freetag) == XFS_DIR2_DATA_FREE_TAG) { + /* + * Check out the biggest freespace and see if it's the same one. + */ + dup = (xfs_dir2_data_unused_t *) + ((char *)hdr + be16_to_cpu(bf[0].offset)); + if (dup != enddup) { + /* + * Not the same free entry, just check its length. + */ + if (be16_to_cpu(dup->length) < len) + dup = NULL; + goto out; + } + + /* + * It is the biggest freespace, can it hold the leaf too? + */ + if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) { + /* + * Yes, use the second-largest entry instead if it works. + */ + if (be16_to_cpu(bf[1].length) >= len) + dup = (xfs_dir2_data_unused_t *) + ((char *)hdr + be16_to_cpu(bf[1].offset)); + else + dup = NULL; + } + } +out: + *tagpp = tagp; + *dupp = dup; + *enddupp = enddup; +} + +/* + * compact the leaf entries. + * Leave the highest-numbered stale entry stale. + * XXX should be the one closest to mid but mid is not yet computed. + */ +static void +xfs_dir2_block_compact( + struct xfs_trans *tp, + struct xfs_buf *bp, + struct xfs_dir2_data_hdr *hdr, + struct xfs_dir2_block_tail *btp, + struct xfs_dir2_leaf_entry *blp, + int *needlog, + int *lfloghigh, + int *lfloglow) +{ + int fromidx; /* source leaf index */ + int toidx; /* target leaf index */ + int needscan = 0; + int highstale; /* high stale index */ + + fromidx = toidx = be32_to_cpu(btp->count) - 1; + highstale = *lfloghigh = -1; + for (; fromidx >= 0; fromidx--) { + if (blp[fromidx].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) { + if (highstale == -1) + highstale = toidx; + else { + if (*lfloghigh == -1) + *lfloghigh = toidx; + continue; + } + } + if (fromidx < toidx) + blp[toidx] = blp[fromidx]; + toidx--; + } + *lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1); + *lfloghigh -= be32_to_cpu(btp->stale) - 1; + be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1)); + xfs_dir2_data_make_free(tp, bp, + (xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr), + (xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)), + needlog, &needscan); + blp += be32_to_cpu(btp->stale) - 1; + btp->stale = cpu_to_be32(1); + /* + * If we now need to rebuild the bestfree map, do so. + * This needs to happen before the next call to use_free. + */ + if (needscan) + xfs_dir2_data_freescan(tp->t_mountp, hdr, needlog); +} + /* * Add an entry to a block directory. */ @@ -63,7 +235,6 @@ int /* error */ xfs_dir2_block_addname( xfs_da_args_t *args) /* directory op arguments */ { - xfs_dir2_data_free_t *bf; /* bestfree table in block */ xfs_dir2_data_hdr_t *hdr; /* block header */ xfs_dir2_leaf_entry_t *blp; /* block leaf entries */ struct xfs_buf *bp; /* buffer for block */ @@ -94,134 +265,44 @@ xfs_dir2_block_addname( dp = args->dp; tp = args->trans; mp = dp->i_mount; - /* - * Read the (one and only) directory block into dabuf bp. - */ - error = xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, - XFS_DATA_FORK, NULL); + + /* Read the (one and only) directory block into bp. */ + error = xfs_dir2_block_read(tp, dp, &bp); if (error) return error; - ASSERT(bp != NULL); - hdr = bp->b_addr; - /* - * Check the magic number, corrupted if wrong. - */ - if (unlikely(hdr->magic != cpu_to_be32(XFS_DIR2_BLOCK_MAGIC))) { - XFS_CORRUPTION_ERROR("xfs_dir2_block_addname", - XFS_ERRLEVEL_LOW, mp, hdr); - xfs_trans_brelse(tp, bp); - return XFS_ERROR(EFSCORRUPTED); - } + len = xfs_dir2_data_entsize(args->namelen); + /* * Set up pointers to parts of the block. */ - bf = hdr->bestfree; + hdr = bp->b_addr; btp = xfs_dir2_block_tail_p(mp, hdr); blp = xfs_dir2_block_leaf_p(btp); + /* - * No stale entries? Need space for entry and new leaf. - */ - if (!btp->stale) { - /* - * Tag just before the first leaf entry. - */ - tagp = (__be16 *)blp - 1; - /* - * Data object just before the first leaf entry. - */ - enddup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp)); - /* - * If it's not free then can't do this add without cleaning up: - * the space before the first leaf entry needs to be free so it - * can be expanded to hold the pointer to the new entry. - */ - if (be16_to_cpu(enddup->freetag) != XFS_DIR2_DATA_FREE_TAG) - dup = enddup = NULL; - /* - * Check out the biggest freespace and see if it's the same one. - */ - else { - dup = (xfs_dir2_data_unused_t *) - ((char *)hdr + be16_to_cpu(bf[0].offset)); - if (dup == enddup) { - /* - * It is the biggest freespace, is it too small - * to hold the new leaf too? - */ - if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) { - /* - * Yes, we use the second-largest - * entry instead if it works. - */ - if (be16_to_cpu(bf[1].length) >= len) - dup = (xfs_dir2_data_unused_t *) - ((char *)hdr + - be16_to_cpu(bf[1].offset)); - else - dup = NULL; - } - } else { - /* - * Not the same free entry, - * just check its length. - */ - if (be16_to_cpu(dup->length) < len) { - dup = NULL; - } - } - } - compact = 0; - } - /* - * If there are stale entries we'll use one for the leaf. - * Is the biggest entry enough to avoid compaction? - */ - else if (be16_to_cpu(bf[0].length) >= len) { - dup = (xfs_dir2_data_unused_t *) - ((char *)hdr + be16_to_cpu(bf[0].offset)); - compact = 0; - } - /* - * Will need to compact to make this work. + * Find out if we can reuse stale entries or whether we need extra + * space for entry and new leaf. */ - else { - /* - * Tag just before the first leaf entry. - */ - tagp = (__be16 *)blp - 1; - /* - * Data object just before the first leaf entry. - */ - dup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp)); - /* - * If it's not free then the data will go where the - * leaf data starts now, if it works at all. - */ - if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { - if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) * - (uint)sizeof(*blp) < len) - dup = NULL; - } else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len) - dup = NULL; - else - dup = (xfs_dir2_data_unused_t *)blp; - compact = 1; - } + xfs_dir2_block_need_space(hdr, btp, blp, &tagp, &dup, + &enddup, &compact, len); + /* - * If this isn't a real add, we're done with the buffer. + * Done everything we need for a space check now. */ - if (args->op_flags & XFS_DA_OP_JUSTCHECK) + if (args->op_flags & XFS_DA_OP_JUSTCHECK) { xfs_trans_brelse(tp, bp); + if (!dup) + return XFS_ERROR(ENOSPC); + return 0; + } + /* * If we don't have space for the new entry & leaf ... */ if (!dup) { - /* - * Not trying to actually do anything, or don't have - * a space reservation: return no-space. - */ - if ((args->op_flags & XFS_DA_OP_JUSTCHECK) || args->total == 0) + /* Don't have a space reservation: return no-space. */ + if (args->total == 0) return XFS_ERROR(ENOSPC); /* * Convert to the next larger format. @@ -232,65 +313,24 @@ xfs_dir2_block_addname( return error; return xfs_dir2_leaf_addname(args); } - /* - * Just checking, and it would work, so say so. - */ - if (args->op_flags & XFS_DA_OP_JUSTCHECK) - return 0; + needlog = needscan = 0; + /* * If need to compact the leaf entries, do it now. - * Leave the highest-numbered stale entry stale. - * XXX should be the one closest to mid but mid is not yet computed. - */ - if (compact) { - int fromidx; /* source leaf index */ - int toidx; /* target leaf index */ - - for (fromidx = toidx = be32_to_cpu(btp->count) - 1, - highstale = lfloghigh = -1; - fromidx >= 0; - fromidx--) { - if (blp[fromidx].address == - cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) { - if (highstale == -1) - highstale = toidx; - else { - if (lfloghigh == -1) - lfloghigh = toidx; - continue; - } - } - if (fromidx < toidx) - blp[toidx] = blp[fromidx]; - toidx--; - } - lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1); - lfloghigh -= be32_to_cpu(btp->stale) - 1; - be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1)); - xfs_dir2_data_make_free(tp, bp, - (xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr), - (xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)), - &needlog, &needscan); - blp += be32_to_cpu(btp->stale) - 1; - btp->stale = cpu_to_be32(1); - /* - * If we now need to rebuild the bestfree map, do so. - * This needs to happen before the next call to use_free. - */ - if (needscan) { - xfs_dir2_data_freescan(mp, hdr, &needlog); - needscan = 0; - } - } - /* - * Set leaf logging boundaries to impossible state. - * For the no-stale case they're set explicitly. */ + if (compact) + xfs_dir2_block_compact(tp, bp, hdr, btp, blp, &needlog, + &lfloghigh, &lfloglow); else if (btp->stale) { + /* + * Set leaf logging boundaries to impossible state. + * For the no-stale case they're set explicitly. + */ lfloglow = be32_to_cpu(btp->count); lfloghigh = -1; } + /* * Find the slot that's first lower than our hash value, -1 if none. */ @@ -450,18 +490,13 @@ xfs_dir2_block_getdents( /* * If the block number in the offset is out of range, we're done. */ - if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk) { + if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk) return 0; - } - /* - * Can't read the block, give up, else get dabuf in bp. - */ - error = xfs_da_read_buf(NULL, dp, mp->m_dirdatablk, -1, - &bp, XFS_DATA_FORK, NULL); + + error = xfs_dir2_block_read(NULL, dp, &bp); if (error) return error; - ASSERT(bp != NULL); /* * Extract the byte offset we start at from the seek pointer. * We'll skip entries before this. @@ -637,14 +672,11 @@ xfs_dir2_block_lookup_int( dp = args->dp; tp = args->trans; mp = dp->i_mount; - /* - * Read the buffer, return error if we can't get it. - */ - error = xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, - XFS_DATA_FORK, NULL); + + error = xfs_dir2_block_read(tp, dp, &bp); if (error) return error; - ASSERT(bp != NULL); + hdr = bp->b_addr; xfs_dir2_data_check(dp, bp); btp = xfs_dir2_block_tail_p(mp, hdr); |