diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_dir2_leaf.c | 434 |
1 files changed, 232 insertions, 202 deletions
diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c index 69accf6cbc4..0b296253bd0 100644 --- a/fs/xfs/xfs_dir2_leaf.c +++ b/fs/xfs/xfs_dir2_leaf.c @@ -759,6 +759,218 @@ xfs_dir2_leaf_compact_x1( *highstalep = highstale; } +struct xfs_dir2_leaf_map_info { + xfs_extlen_t map_blocks; /* number of fsbs in map */ + xfs_dablk_t map_off; /* last mapped file offset */ + int map_size; /* total entries in *map */ + int map_valid; /* valid entries in *map */ + int nmap; /* mappings to ask xfs_bmapi */ + xfs_dir2_db_t curdb; /* db for current block */ + int ra_current; /* number of read-ahead blks */ + int ra_index; /* *map index for read-ahead */ + int ra_offset; /* map entry offset for ra */ + int ra_want; /* readahead count wanted */ + struct xfs_bmbt_irec map[]; /* map vector for blocks */ +}; + +STATIC int +xfs_dir2_leaf_readbuf( + struct xfs_inode *dp, + size_t bufsize, + struct xfs_dir2_leaf_map_info *mip, + xfs_dir2_off_t *curoff, + struct xfs_buf **bpp) +{ + struct xfs_mount *mp = dp->i_mount; + struct xfs_buf *bp = *bpp; + struct xfs_bmbt_irec *map = mip->map; + int error = 0; + int length; + int i; + int j; + + /* + * If we have a buffer, we need to release it and + * take it out of the mapping. + */ + + if (bp) { + xfs_trans_brelse(NULL, bp); + bp = NULL; + mip->map_blocks -= mp->m_dirblkfsbs; + /* + * Loop to get rid of the extents for the + * directory block. + */ + for (i = mp->m_dirblkfsbs; i > 0; ) { + j = min_t(int, map->br_blockcount, i); + map->br_blockcount -= j; + map->br_startblock += j; + map->br_startoff += j; + /* + * If mapping is done, pitch it from + * the table. + */ + if (!map->br_blockcount && --mip->map_valid) + memmove(&map[0], &map[1], + sizeof(map[0]) * mip->map_valid); + i -= j; + } + } + + /* + * Recalculate the readahead blocks wanted. + */ + mip->ra_want = howmany(bufsize + mp->m_dirblksize, + mp->m_sb.sb_blocksize) - 1; + ASSERT(mip->ra_want >= 0); + + /* + * If we don't have as many as we want, and we haven't + * run out of data blocks, get some more mappings. + */ + if (1 + mip->ra_want > mip->map_blocks && + mip->map_off < xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) { + /* + * Get more bmaps, fill in after the ones + * we already have in the table. + */ + mip->nmap = mip->map_size - mip->map_valid; + error = xfs_bmapi_read(dp, mip->map_off, + xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET) - + mip->map_off, + &map[mip->map_valid], &mip->nmap, 0); + + /* + * Don't know if we should ignore this or try to return an + * error. The trouble with returning errors is that readdir + * will just stop without actually passing the error through. + */ + if (error) + goto out; /* XXX */ + + /* + * If we got all the mappings we asked for, set the final map + * offset based on the last bmap value received. Otherwise, + * we've reached the end. + */ + if (mip->nmap == mip->map_size - mip->map_valid) { + i = mip->map_valid + mip->nmap - 1; + mip->map_off = map[i].br_startoff + map[i].br_blockcount; + } else + mip->map_off = xfs_dir2_byte_to_da(mp, + XFS_DIR2_LEAF_OFFSET); + + /* + * Look for holes in the mapping, and eliminate them. Count up + * the valid blocks. + */ + for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) { + if (map[i].br_startblock == HOLESTARTBLOCK) { + mip->nmap--; + length = mip->map_valid + mip->nmap - i; + if (length) + memmove(&map[i], &map[i + 1], + sizeof(map[i]) * length); + } else { + mip->map_blocks += map[i].br_blockcount; + i++; + } + } + mip->map_valid += mip->nmap; + } + + /* + * No valid mappings, so no more data blocks. + */ + if (!mip->map_valid) { + *curoff = xfs_dir2_da_to_byte(mp, mip->map_off); + goto out; + } + + /* + * Read the directory block starting at the first mapping. + */ + mip->curdb = xfs_dir2_da_to_db(mp, map->br_startoff); + error = xfs_da_read_buf(NULL, dp, map->br_startoff, + map->br_blockcount >= mp->m_dirblkfsbs ? + XFS_FSB_TO_DADDR(mp, map->br_startblock) : -1, + &bp, XFS_DATA_FORK); + + /* + * Should just skip over the data block instead of giving up. + */ + if (error) + goto out; /* XXX */ + + /* + * Adjust the current amount of read-ahead: we just read a block that + * was previously ra. + */ + if (mip->ra_current) + mip->ra_current -= mp->m_dirblkfsbs; + + /* + * Do we need more readahead? + */ + for (mip->ra_index = mip->ra_offset = i = 0; + mip->ra_want > mip->ra_current && i < mip->map_blocks; + i += mp->m_dirblkfsbs) { + ASSERT(mip->ra_index < mip->map_valid); + /* + * Read-ahead a contiguous directory block. + */ + if (i > mip->ra_current && + map[mip->ra_index].br_blockcount >= mp->m_dirblkfsbs) { + xfs_buf_readahead(mp->m_ddev_targp, + XFS_FSB_TO_DADDR(mp, + map[mip->ra_index].br_startblock + + mip->ra_offset), + (int)BTOBB(mp->m_dirblksize)); + mip->ra_current = i; + } + + /* + * Read-ahead a non-contiguous directory block. This doesn't + * use our mapping, but this is a very rare case. + */ + else if (i > mip->ra_current) { + xfs_da_reada_buf(NULL, dp, + map[mip->ra_index].br_startoff + + mip->ra_offset, + XFS_DATA_FORK); + mip->ra_current = i; + } + + /* + * Advance offset through the mapping table. + */ + for (j = 0; j < mp->m_dirblkfsbs; j++) { + /* + * The rest of this extent but not more than a dir + * block. + */ + length = min_t(int, mp->m_dirblkfsbs, + map[mip->ra_index].br_blockcount - + mip->ra_offset); + j += length; + mip->ra_offset += length; + + /* + * Advance to the next mapping if this one is used up. + */ + if (mip->ra_offset == map[mip->ra_index].br_blockcount) { + mip->ra_offset = 0; + mip->ra_index++; + } + } + } + +out: + *bpp = bp; + return error; +} + /* * Getdents (readdir) for leaf and node directories. * This reads the data blocks only, so is the same for both forms. @@ -771,30 +983,18 @@ xfs_dir2_leaf_getdents( xfs_off_t *offset, filldir_t filldir) { - struct xfs_buf *bp; /* data block buffer */ - int byteoff; /* offset in current block */ - xfs_dir2_db_t curdb; /* db for current block */ - xfs_dir2_off_t curoff; /* current overall offset */ + struct xfs_buf *bp = NULL; /* data block buffer */ xfs_dir2_data_hdr_t *hdr; /* data block header */ xfs_dir2_data_entry_t *dep; /* data entry */ xfs_dir2_data_unused_t *dup; /* unused entry */ int error = 0; /* error return value */ - int i; /* temporary loop index */ - int j; /* temporary loop index */ int length; /* temporary length value */ - xfs_bmbt_irec_t *map; /* map vector for blocks */ - xfs_extlen_t map_blocks; /* number of fsbs in map */ - xfs_dablk_t map_off; /* last mapped file offset */ - int map_size; /* total entries in *map */ - int map_valid; /* valid entries in *map */ xfs_mount_t *mp; /* filesystem mount point */ + int byteoff; /* offset in current block */ + xfs_dir2_off_t curoff; /* current overall offset */ xfs_dir2_off_t newoff; /* new curoff after new blk */ - int nmap; /* mappings to ask xfs_bmapi */ char *ptr = NULL; /* pointer to current data */ - int ra_current; /* number of read-ahead blks */ - int ra_index; /* *map index for read-ahead */ - int ra_offset; /* map entry offset for ra */ - int ra_want; /* readahead count wanted */ + struct xfs_dir2_leaf_map_info *map_info; /* * If the offset is at or past the largest allowed value, @@ -810,10 +1010,12 @@ xfs_dir2_leaf_getdents( * buffer size, the directory block size, and the filesystem * block size. */ - map_size = howmany(bufsize + mp->m_dirblksize, mp->m_sb.sb_blocksize); - map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP); - map_valid = ra_index = ra_offset = ra_current = map_blocks = 0; - bp = NULL; + length = howmany(bufsize + mp->m_dirblksize, + mp->m_sb.sb_blocksize); + map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) + + (length * sizeof(struct xfs_bmbt_irec)), + KM_SLEEP); + map_info->map_size = length; /* * Inside the loop we keep the main offset value as a byte offset @@ -825,7 +1027,9 @@ xfs_dir2_leaf_getdents( * Force this conversion through db so we truncate the offset * down to get the start of the data block. */ - map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff)); + map_info->map_off = xfs_dir2_db_to_da(mp, + xfs_dir2_byte_to_db(mp, curoff)); + /* * Loop over directory entries until we reach the end offset. * Get more blocks and readahead as necessary. @@ -836,190 +1040,16 @@ xfs_dir2_leaf_getdents( * current buffer, need to get another one. */ if (!bp || ptr >= (char *)bp->b_addr + mp->m_dirblksize) { - /* - * If we have a buffer, we need to release it and - * take it out of the mapping. - */ - if (bp) { - xfs_trans_brelse(NULL, bp); - bp = NULL; - map_blocks -= mp->m_dirblkfsbs; - /* - * Loop to get rid of the extents for the - * directory block. - */ - for (i = mp->m_dirblkfsbs; i > 0; ) { - j = MIN((int)map->br_blockcount, i); - map->br_blockcount -= j; - map->br_startblock += j; - map->br_startoff += j; - /* - * If mapping is done, pitch it from - * the table. - */ - if (!map->br_blockcount && --map_valid) - memmove(&map[0], &map[1], - sizeof(map[0]) * - map_valid); - i -= j; - } - } - /* - * Recalculate the readahead blocks wanted. - */ - ra_want = howmany(bufsize + mp->m_dirblksize, - mp->m_sb.sb_blocksize) - 1; - ASSERT(ra_want >= 0); - /* - * If we don't have as many as we want, and we haven't - * run out of data blocks, get some more mappings. - */ - if (1 + ra_want > map_blocks && - map_off < - xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) { - /* - * Get more bmaps, fill in after the ones - * we already have in the table. - */ - nmap = map_size - map_valid; - error = xfs_bmapi_read(dp, map_off, - xfs_dir2_byte_to_da(mp, - XFS_DIR2_LEAF_OFFSET) - map_off, - &map[map_valid], &nmap, 0); - /* - * Don't know if we should ignore this or - * try to return an error. - * The trouble with returning errors - * is that readdir will just stop without - * actually passing the error through. - */ - if (error) - break; /* XXX */ - /* - * If we got all the mappings we asked for, - * set the final map offset based on the - * last bmap value received. - * Otherwise, we've reached the end. - */ - if (nmap == map_size - map_valid) - map_off = - map[map_valid + nmap - 1].br_startoff + - map[map_valid + nmap - 1].br_blockcount; - else - map_off = - xfs_dir2_byte_to_da(mp, - XFS_DIR2_LEAF_OFFSET); - /* - * Look for holes in the mapping, and - * eliminate them. Count up the valid blocks. - */ - for (i = map_valid; i < map_valid + nmap; ) { - if (map[i].br_startblock == - HOLESTARTBLOCK) { - nmap--; - length = map_valid + nmap - i; - if (length) - memmove(&map[i], - &map[i + 1], - sizeof(map[i]) * - length); - } else { - map_blocks += - map[i].br_blockcount; - i++; - } - } - map_valid += nmap; - } - /* - * No valid mappings, so no more data blocks. - */ - if (!map_valid) { - curoff = xfs_dir2_da_to_byte(mp, map_off); + error = xfs_dir2_leaf_readbuf(dp, bufsize, map_info, + &curoff, &bp); + if (error || !map_info->map_valid) break; - } - /* - * Read the directory block starting at the first - * mapping. - */ - curdb = xfs_dir2_da_to_db(mp, map->br_startoff); - error = xfs_da_read_buf(NULL, dp, map->br_startoff, - map->br_blockcount >= mp->m_dirblkfsbs ? - XFS_FSB_TO_DADDR(mp, map->br_startblock) : - -1, - &bp, XFS_DATA_FORK); - /* - * Should just skip over the data block instead - * of giving up. - */ - if (error) - break; /* XXX */ - /* - * Adjust the current amount of read-ahead: we just - * read a block that was previously ra. - */ - if (ra_current) - ra_current -= mp->m_dirblkfsbs; - /* - * Do we need more readahead? - */ - for (ra_index = ra_offset = i = 0; - ra_want > ra_current && i < map_blocks; - i += mp->m_dirblkfsbs) { - ASSERT(ra_index < map_valid); - /* - * Read-ahead a contiguous directory block. - */ - if (i > ra_current && - map[ra_index].br_blockcount >= - mp->m_dirblkfsbs) { - xfs_buf_readahead(mp->m_ddev_targp, - XFS_FSB_TO_DADDR(mp, - map[ra_index].br_startblock + - ra_offset), - (int)BTOBB(mp->m_dirblksize)); - ra_current = i; - } - /* - * Read-ahead a non-contiguous directory block. - * This doesn't use our mapping, but this - * is a very rare case. - */ - else if (i > ra_current) { - (void)xfs_da_reada_buf(NULL, dp, - map[ra_index].br_startoff + - ra_offset, XFS_DATA_FORK); - ra_current = i; - } - /* - * Advance offset through the mapping table. - */ - for (j = 0; j < mp->m_dirblkfsbs; j++) { - /* - * The rest of this extent but not - * more than a dir block. - */ - length = MIN(mp->m_dirblkfsbs, - (int)(map[ra_index].br_blockcount - - ra_offset)); - j += length; - ra_offset += length; - /* - * Advance to the next mapping if - * this one is used up. - */ - if (ra_offset == - map[ra_index].br_blockcount) { - ra_offset = 0; - ra_index++; - } - } - } + /* * Having done a read, we need to set a new offset. */ - newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0); + newoff = xfs_dir2_db_off_to_byte(mp, map_info->curdb, 0); /* * Start of the current block. */ @@ -1030,7 +1060,7 @@ xfs_dir2_leaf_getdents( */ else if (curoff > newoff) ASSERT(xfs_dir2_byte_to_db(mp, curoff) == - curdb); + map_info->curdb); hdr = bp->b_addr; xfs_dir2_data_check(dp, bp); /* @@ -1113,7 +1143,7 @@ xfs_dir2_leaf_getdents( *offset = XFS_DIR2_MAX_DATAPTR & 0x7fffffff; else *offset = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff; - kmem_free(map); + kmem_free(map_info); if (bp) xfs_trans_brelse(NULL, bp); return error; |