diff options
Diffstat (limited to 'fs/hpfs/alloc.c')
-rw-r--r-- | fs/hpfs/alloc.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c index f005046e1..d6a4b55d2 100644 --- a/fs/hpfs/alloc.c +++ b/fs/hpfs/alloc.c @@ -484,3 +484,98 @@ struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *a a->btree.first_free = cpu_to_le16(8); return a; } + +static unsigned find_run(__le32 *bmp, unsigned *idx) +{ + unsigned len; + while (tstbits(bmp, *idx, 1)) { + (*idx)++; + if (unlikely(*idx >= 0x4000)) + return 0; + } + len = 1; + while (!tstbits(bmp, *idx + len, 1)) + len++; + return len; +} + +static int do_trim(struct super_block *s, secno start, unsigned len, secno limit_start, secno limit_end, unsigned minlen, unsigned *result) +{ + int err; + secno end; + if (fatal_signal_pending(current)) + return -EINTR; + end = start + len; + if (start < limit_start) + start = limit_start; + if (end > limit_end) + end = limit_end; + if (start >= end) + return 0; + if (end - start < minlen) + return 0; + err = sb_issue_discard(s, start, end - start, GFP_NOFS, 0); + if (err) + return err; + *result += end - start; + return 0; +} + +int hpfs_trim_fs(struct super_block *s, u64 start, u64 end, u64 minlen, unsigned *result) +{ + int err = 0; + struct hpfs_sb_info *sbi = hpfs_sb(s); + unsigned idx, len, start_bmp, end_bmp; + __le32 *bmp; + struct quad_buffer_head qbh; + + *result = 0; + if (!end || end > sbi->sb_fs_size) + end = sbi->sb_fs_size; + if (start >= sbi->sb_fs_size) + return 0; + if (minlen > 0x4000) + return 0; + if (start < sbi->sb_dirband_start + sbi->sb_dirband_size && end > sbi->sb_dirband_start) { + hpfs_lock(s); + if (s->s_flags & MS_RDONLY) { + err = -EROFS; + goto unlock_1; + } + if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) { + err = -EIO; + goto unlock_1; + } + idx = 0; + while ((len = find_run(bmp, &idx)) && !err) { + err = do_trim(s, sbi->sb_dirband_start + idx * 4, len * 4, start, end, minlen, result); + idx += len; + } + hpfs_brelse4(&qbh); +unlock_1: + hpfs_unlock(s); + } + start_bmp = start >> 14; + end_bmp = (end + 0x3fff) >> 14; + while (start_bmp < end_bmp && !err) { + hpfs_lock(s); + if (s->s_flags & MS_RDONLY) { + err = -EROFS; + goto unlock_2; + } + if (!(bmp = hpfs_map_bitmap(s, start_bmp, &qbh, "trim"))) { + err = -EIO; + goto unlock_2; + } + idx = 0; + while ((len = find_run(bmp, &idx)) && !err) { + err = do_trim(s, (start_bmp << 14) + idx, len, start, end, minlen, result); + idx += len; + } + hpfs_brelse4(&qbh); +unlock_2: + hpfs_unlock(s); + start_bmp++; + } + return err; +} |