/* * Add an entry to a block directory. */ int /* error */ xfs_dir2_block_addname( xfs_da_args_t *args) /* directory op arguments */ { xfs_dir2_data_hdr_t *hdr; /* block header */ xfs_dir2_leaf_entry_t *blp; /* block leaf entries */ struct xfs_buf *bp; /* buffer for block */ xfs_dir2_block_tail_t *btp; /* block tail */ int compact; /* need to compact leaf ents */ xfs_dir2_data_entry_t *dep; /* block data entry */ xfs_inode_t *dp; /* directory inode */ xfs_dir2_data_unused_t *dup; /* block unused entry */ int error; /* error return value */ xfs_dir2_data_unused_t *enddup=NULL; /* unused at end of data */ xfs_dahash_t hash; /* hash value of found entry */ int high; /* high index for binary srch */ int highstale; /* high stale index */ int lfloghigh=0; /* last final leaf to log */ int lfloglow=0; /* first final leaf to log */ int len; /* length of the new entry */ int low; /* low index for binary srch */ int lowstale; /* low stale index */ int mid=0; /* midpoint for binary srch */ int needlog; /* need to log header */ int needscan; /* need to rescan freespace */ __be16 *tagp; /* pointer to tag value */ xfs_trans_t *tp; /* transaction structure */ trace_xfs_dir2_block_addname(args); dp = args->dp; tp = args->trans; /* Read the (one and only) directory block into bp. */ error = xfs_dir3_block_read(tp, dp, &bp); if (error) return error; len = dp->d_ops->data_entsize(args->namelen); /* * Set up pointers to parts of the block. */ hdr = bp->b_addr; btp = xfs_dir2_block_tail_p(args->geo, hdr); blp = xfs_dir2_block_leaf_p(btp); /* * Find out if we can reuse stale entries or whether we need extra * space for entry and new leaf. */ xfs_dir2_block_need_space(dp, hdr, btp, blp, &tagp, &dup, &enddup, &compact, len); /* * Done everything we need for a space check now. */ if (args->op_flags & XFS_DA_OP_JUSTCHECK) { xfs_trans_brelse(tp, bp); if (!dup) return -ENOSPC; return 0; } /* * If we don't have space for the new entry & leaf ... */ if (!dup) { /* Don't have a space reservation: return no-space. */ if (args->total == 0) return -ENOSPC; /* * Convert to the next larger format. * Then add the new entry in that format. */ error = xfs_dir2_block_to_leaf(args, bp); if (error) return error; return xfs_dir2_leaf_addname(args); } needlog = needscan = 0; /* * If need to compact the leaf entries, do it now. */ if (compact) { xfs_dir2_block_compact(args, bp, hdr, btp, blp, &needlog, &lfloghigh, &lfloglow); /* recalculate blp post-compaction */ blp = xfs_dir2_block_leaf_p(btp); } 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. */ for (low = 0, high = be32_to_cpu(btp->count) - 1; low <= high; ) { mid = (low + high) >> 1; if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval) break; if (hash < args->hashval) low = mid + 1; else high = mid - 1; } while (mid >= 0 && be32_to_cpu(blp[mid].hashval) >= args->hashval) { mid--; } /* * No stale entries, will use enddup space to hold new leaf. */ if (!btp->stale) { /* * Mark the space needed for the new leaf entry, now in use. */ xfs_dir2_data_use_free(args, bp, enddup, (xfs_dir2_data_aoff_t) ((char *)enddup - (char *)hdr + be16_to_cpu(enddup->length) - sizeof(*blp)), (xfs_dir2_data_aoff_t)sizeof(*blp), &needlog, &needscan); /* * Update the tail (entry count). */ be32_add_cpu(&btp->count, 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(dp, hdr, &needlog); needscan = 0; } /* * Adjust pointer to the first leaf entry, we're about to move * the table up one to open up space for the new leaf entry. * Then adjust our index to match. */ blp--; mid++; if (mid) memmove(blp, &blp[1], mid * sizeof(*blp)); lfloglow = 0; lfloghigh = mid; } /* * Use a stale leaf for our new entry. */ else { for (lowstale = mid; lowstale >= 0 && blp[lowstale].address != cpu_to_be32(XFS_DIR2_NULL_DATAPTR); lowstale--) continue; for (highstale = mid + 1; highstale < be32_to_cpu(btp->count) && blp[highstale].address != cpu_to_be32(XFS_DIR2_NULL_DATAPTR) && (lowstale < 0 || mid - lowstale > highstale - mid); highstale++) continue; /* * Move entries toward the low-numbered stale entry. */ if (lowstale >= 0 && (highstale == be32_to_cpu(btp->count) || mid - lowstale <= highstale - mid)) { if (mid - lowstale) memmove(&blp[lowstale], &blp[lowstale + 1], (mid - lowstale) * sizeof(*blp)); lfloglow = MIN(lowstale, lfloglow); lfloghigh = MAX(mid, lfloghigh); } /* * Move entries toward the high-numbered stale entry. */ else { ASSERT(highstale < be32_to_cpu(btp->count)); mid++; if (highstale - mid) memmove(&blp[mid + 1], &blp[mid], (highstale - mid) * sizeof(*blp)); lfloglow = MIN(mid, lfloglow); lfloghigh = MAX(highstale, lfloghigh); } be32_add_cpu(&btp->stale, -1); } /* * Point to the new data entry. */ dep = (xfs_dir2_data_entry_t *)dup; /* * Fill in the leaf entry. */ blp[mid].hashval = cpu_to_be32(args->hashval); blp[mid].address = cpu_to_be32(xfs_dir2_byte_to_dataptr( (char *)dep - (char *)hdr)); xfs_dir2_block_log_leaf(tp, bp, lfloglow, lfloghigh); /* * Mark space for the data entry used. */ xfs_dir2_data_use_free(args, bp, dup, (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr), (xfs_dir2_data_aoff_t)len, &needlog, &needscan); /* * Create the new data entry. */ dep->inumber = cpu_to_be64(args->inumber); dep->namelen = args->namelen; memcpy(dep->name, args->name, args->namelen); dp->d_ops->data_put_ftype(dep, args->filetype); tagp = dp->d_ops->data_entry_tag_p(dep); *tagp = cpu_to_be16((char *)dep - (char *)hdr); /* * Clean up the bestfree array and log the header, tail, and entry. */ if (needscan) xfs_dir2_data_freescan(dp, hdr, &needlog); if (needlog) xfs_dir2_data_log_header(args, bp); xfs_dir2_block_log_tail(tp, bp); xfs_dir2_data_log_entry(args, bp, dep); xfs_dir3_data_check(dp, bp); return 0; }
/* * Internal block lookup routine. */ static int /* error */ xfs_dir2_block_lookup_int( xfs_da_args_t *args, /* dir lookup arguments */ struct xfs_buf **bpp, /* returned block buffer */ int *entno) /* returned entry number */ { xfs_dir2_dataptr_t addr; /* data entry address */ xfs_dir2_data_hdr_t *hdr; /* block header */ xfs_dir2_leaf_entry_t *blp; /* block leaf entries */ struct xfs_buf *bp; /* block buffer */ xfs_dir2_block_tail_t *btp; /* block tail */ xfs_dir2_data_entry_t *dep; /* block data entry */ xfs_inode_t *dp; /* incore inode */ int error; /* error return value */ xfs_dahash_t hash; /* found hash value */ int high; /* binary search high index */ int low; /* binary search low index */ int mid; /* binary search current idx */ xfs_mount_t *mp; /* filesystem mount point */ xfs_trans_t *tp; /* transaction pointer */ enum xfs_dacmp cmp; /* comparison result */ dp = args->dp; tp = args->trans; mp = dp->i_mount; error = xfs_dir3_block_read(tp, dp, &bp); if (error) return error; hdr = bp->b_addr; xfs_dir3_data_check(dp, bp); btp = xfs_dir2_block_tail_p(args->geo, hdr); blp = xfs_dir2_block_leaf_p(btp); /* * Loop doing a binary search for our hash value. * Find our entry, ENOENT if it's not there. */ for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) { ASSERT(low <= high); mid = (low + high) >> 1; if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval) break; if (hash < args->hashval) low = mid + 1; else high = mid - 1; if (low > high) { ASSERT(args->op_flags & XFS_DA_OP_OKNOENT); xfs_trans_brelse(tp, bp); return -ENOENT; } } /* * Back up to the first one with the right hash value. */ while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) { mid--; } /* * Now loop forward through all the entries with the * right hash value looking for our name. */ do { if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR) continue; /* * Get pointer to the entry from the leaf. */ dep = (xfs_dir2_data_entry_t *) ((char *)hdr + xfs_dir2_dataptr_to_off(args->geo, addr)); /* * Compare name and if it's an exact match, return the index * and buffer. If it's the first case-insensitive match, store * the index and buffer and continue looking for an exact match. */ cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen); if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) { args->cmpresult = cmp; *bpp = bp; *entno = mid; if (cmp == XFS_CMP_EXACT) return 0; } } while (++mid < be32_to_cpu(btp->count) && be32_to_cpu(blp[mid].hashval) == hash); ASSERT(args->op_flags & XFS_DA_OP_OKNOENT); /* * Here, we can only be doing a lookup (not a rename or replace). * If a case-insensitive match was found earlier, return success. */ if (args->cmpresult == XFS_CMP_CASE) return 0; /* * No match, release the buffer and return ENOENT. */ xfs_trans_brelse(tp, bp); return -ENOENT; }
/* * Readdir for block directories. */ STATIC int xfs_dir2_block_getdents( xfs_inode_t *dp, /* incore inode */ struct dir_context *ctx) { xfs_dir2_data_hdr_t *hdr; /* block header */ struct xfs_buf *bp; /* buffer for block */ xfs_dir2_block_tail_t *btp; /* block tail */ xfs_dir2_data_entry_t *dep; /* block data entry */ xfs_dir2_data_unused_t *dup; /* block unused entry */ char *endptr; /* end of the data entries */ int error; /* error return value */ xfs_mount_t *mp; /* filesystem mount point */ char *ptr; /* current data entry */ int wantoff; /* starting block offset */ xfs_off_t cook; mp = dp->i_mount; /* * If the block number in the offset is out of range, we're done. */ if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk) return 0; error = xfs_dir3_block_read(NULL, dp, &bp); if (error) return error; /* * Extract the byte offset we start at from the seek pointer. * We'll skip entries before this. */ wantoff = xfs_dir2_dataptr_to_off(mp, ctx->pos); hdr = bp->b_addr; xfs_dir3_data_check(dp, bp); /* * Set up values for the loop. */ btp = xfs_dir2_block_tail_p(mp, hdr); ptr = (char *)dp->d_ops->data_entry_p(hdr); endptr = (char *)xfs_dir2_block_leaf_p(btp); /* * Loop over the data portion of the block. * Each object is a real entry (dep) or an unused one (dup). */ while (ptr < endptr) { __uint8_t filetype; dup = (xfs_dir2_data_unused_t *)ptr; /* * Unused, skip it. */ if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { ptr += be16_to_cpu(dup->length); continue; } dep = (xfs_dir2_data_entry_t *)ptr; /* * Bump pointer for the next iteration. */ ptr += dp->d_ops->data_entsize(dep->namelen); /* * The entry is before the desired starting point, skip it. */ if ((char *)dep - (char *)hdr < wantoff) continue; cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, (char *)dep - (char *)hdr); ctx->pos = cook & 0x7fffffff; filetype = dp->d_ops->data_get_ftype(dep); /* * If it didn't fit, set the final offset to here & return. */ if (!dir_emit(ctx, (char *)dep->name, dep->namelen, be64_to_cpu(dep->inumber), xfs_dir3_get_dtype(mp, filetype))) { xfs_trans_brelse(NULL, bp); return 0; } } /* * Reached the end of the block. * Set the offset to a non-existent block 1 and return. */ ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) & 0x7fffffff; xfs_trans_brelse(NULL, bp); return 0; }