fuse2fs: fix FITRIM validation

Fix the validation here to match the kernel, and report the number of
blocks trimmed.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/174553065195.1160461.15575039465292160279.stgit@frogsfrogsfrogs
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index eb37021..178d3eb 100644 (file)
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -3206,17 +3206,27 @@ static int ioctl_fitrim(struct fuse2fs *ff, struct fuse2fs_file_handle *fh,
 {
        ext2_filsys fs = ff->fs;
        struct fstrim_range *fr = data;
-       blk64_t start, end, max_blocks, b, cleared;
+       blk64_t start, end, max_blocks, b, cleared, minlen;
+       blk64_t max_blks = ext2fs_blocks_count(fs->super);
        errcode_t err = 0;
 
+       if (!fs_writeable(fs))
+               return -EROFS;
+
        start = fr->start / fs->blocksize;
        end = (fr->start + fr->len - 1) / fs->blocksize;
-       dbg_printf(ff, "%s: start=%llu end=%llu\n", __func__, start, end);
+       minlen = fr->minlen / fs->blocksize;
+
+       if (EXT2FS_NUM_B2C(fs, minlen) > EXT2_CLUSTERS_PER_GROUP(fs->super) ||
+           start >= max_blks ||
+           fr->len < fs->blocksize)
+               return -EINVAL;
+
+       dbg_printf(ff, "%s: start=%llu end=%llu minlen=%llu\n", __func__,
+                  start, end, minlen);
 
        if (start < fs->super->s_first_data_block)
                start = fs->super->s_first_data_block;
-       if (start >= ext2fs_blocks_count(fs->super))
-               start = ext2fs_blocks_count(fs->super) - 1;
 
        if (end < fs->super->s_first_data_block)
                end = fs->super->s_first_data_block;
@@ -3230,17 +3240,23 @@ static int ioctl_fitrim(struct fuse2fs *ff, struct fuse2fs_file_handle *fh,
        while (start <= end) {
                err = ext2fs_find_first_zero_block_bitmap2(fs->block_map,
                                                           start, end, &start);
-               if (err == ENOENT)
-                       return 0;
-               else if (err)
+               switch (err) {
+               case 0:
+                       break;
+               case ENOENT:
+                       /* no free blocks found, so we're done */
+                       err = 0;
+                       goto out;
+               default:
                        return translate_error(fs, fh->ino, err);
+               }
 
                b = start + max_blocks < end ? start + max_blocks : end;
                err =  ext2fs_find_first_set_block_bitmap2(fs->block_map,
                                                           start, b, &b);
                if (err && err != ENOENT)
                        return translate_error(fs, fh->ino, err);
-               if (b - start >= fr->minlen) {
+               if (b - start >= minlen) {
                        err = io_channel_discard(fs->io, start, b - start);
                        if (err)
                                return translate_error(fs, fh->ino, err);
@@ -3250,6 +3266,8 @@ static int ioctl_fitrim(struct fuse2fs *ff, struct fuse2fs_file_handle *fh,
                start = b + 1;
        }
 
+out:
+       fr->len = cleared;
        return err;
 }
 #endif /* FITRIM */