hpfs: add fstrim support
This patch adds support for fstrim to the HPFS filesystem.
Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c
index f005046..d6a4b55 100644
--- a/fs/hpfs/alloc.c
+++ b/fs/hpfs/alloc.c
@@ -484,3 +484,98 @@
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;
+}