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>

5 files changed, 128 insertions, 0 deletions

diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c
index f005046e1591..d6a4b55d2ab0 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;
+}
diff --git a/fs/hpfs/dir.c b/fs/hpfs/dir.c
index 2a8e07425de0..dc540bfcee1d 100644
--- a/fs/hpfs/dir.c
+++ b/fs/hpfs/dir.c
@@ -327,4 +327,5 @@ const struct file_operations hpfs_dir_ops =
         .iterate        = hpfs_readdir,
         .release        = hpfs_dir_release,
         .fsync          = hpfs_file_fsync,
+        .unlocked_ioctl = hpfs_ioctl,
 };
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 6d8cfe9b52d6..7ca28d604bf7 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -203,6 +203,7 @@ const struct file_operations hpfs_file_ops =
         .release        = hpfs_file_release,
         .fsync          = hpfs_file_fsync,
         .splice_read    = generic_file_splice_read,
+        .unlocked_ioctl = hpfs_ioctl,
 };
 
 const struct inode_operations hpfs_file_iops =
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index bb04b58d1d69..c4867b5116dd 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -18,6 +18,8 @@
 #include <linux/pagemap.h>
 #include <linux/buffer_head.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/blkdev.h>
 #include <asm/unaligned.h>
 
 #include "hpfs.h"
@@ -200,6 +202,7 @@ void hpfs_free_dnode(struct super_block *, secno);
 struct dnode *hpfs_alloc_dnode(struct super_block *, secno, dnode_secno *, struct quad_buffer_head *);
 struct fnode *hpfs_alloc_fnode(struct super_block *, secno, fnode_secno *, struct buffer_head **);
 struct anode *hpfs_alloc_anode(struct super_block *, secno, anode_secno *, struct buffer_head **);
+int hpfs_trim_fs(struct super_block *, u64, u64, u64, unsigned *);
 
 /* anode.c */
 
@@ -318,6 +321,7 @@ __printf(2, 3)
 void hpfs_error(struct super_block *, const char *, ...);
 int hpfs_stop_cycles(struct super_block *, int, int *, int *, char *);
 unsigned hpfs_get_free_dnodes(struct super_block *);
+long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 
 /*
  * local time (HPFS) to GMT (Unix)
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index 7cd00d3a7c9b..037e3e597ff4 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -196,6 +196,33 @@ static int hpfs_statfs(struct dentry *dentry, struct kstatfs *buf)
         return 0;
 }
 
+
+long hpfs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+        switch (cmd) {
+                case FITRIM: {
+                        struct fstrim_range range;
+                        secno n_trimmed;
+                        int r;
+                        if (!capable(CAP_SYS_ADMIN))
+                                return -EPERM;
+                        if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
+                                return -EFAULT;
+                        r = hpfs_trim_fs(file_inode(file)->i_sb, range.start >> 9, (range.start + range.len) >> 9, (range.minlen + 511) >> 9, &n_trimmed);
+                        if (r)
+                                return r;
+                        range.len = (u64)n_trimmed << 9;
+                        if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
+                                return -EFAULT;
+                        return 0;
+                }
+                default: {
+                        return -ENOIOCTLCMD;
+                }
+        }
+}
+
+
 static struct kmem_cache * hpfs_inode_cachep;
 
 static struct inode *hpfs_alloc_inode(struct super_block *sb)