From: Qu Wenruo wqu@suse.com
[BUG] fstrim on some btrfs only trims the unallocated space, not trimming any space in existing block groups.
[CAUSE] Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to range [0, super->total_bytes). So later btrfs_trim_fs() will only be able to trim block groups in range [0, super->total_bytes).
While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs uses its logical address space, there is nothing limiting the location where we put block groups.
For filesystem with frequent balance, it's quite easy to relocate all block groups and bytenr of block groups will start beyond super->total_bytes.
In that case, btrfs will not trim existing block groups.
[FIX] Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs() can get the unmodified range, which is normally set to [0, U64_MAX].
Reported-by: Chris Murphy lists@colorremedies.com Fixes: f4c697e6406d ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl") CC: stable@vger.kernel.org # v4.4+ Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: Nikolay Borisov nborisov@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com ---
Hello Greg,
Please apply upstream commit 6ba9fc8e628becf0e3ec94083450d089b0dec5f5 to 4.4.y and 4.9.y. This backport should apply cleanly to both trees. fs/btrfs/extent-tree.c | 10 +--------- fs/btrfs/ioctl.c | 11 +++++++---- 2 files changed, 8 insertions(+), 13 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a72f941ca750..0cea1abe4a64 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -10680,17 +10680,9 @@ int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) u64 start; u64 end; u64 trimmed = 0; - u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); int ret = 0;
- /* - * try to trim all FS space, our block group may start from non-zero. - */ - if (range->len == total_bytes) - cache = btrfs_lookup_first_block_group(fs_info, range->start); - else - cache = btrfs_lookup_block_group(fs_info, range->start); - + cache = btrfs_lookup_first_block_group(fs_info, range->start); while (cache) { if (cache->key.objectid >= (range->start + range->len)) { btrfs_put_block_group(cache); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6caeb946fc1d..253ba72ef855 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -378,7 +378,6 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) struct fstrim_range range; u64 minlen = ULLONG_MAX; u64 num_devices = 0; - u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); int ret;
if (!capable(CAP_SYS_ADMIN)) @@ -402,11 +401,15 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) return -EOPNOTSUPP; if (copy_from_user(&range, arg, sizeof(range))) return -EFAULT; - if (range.start > total_bytes || - range.len < fs_info->sb->s_blocksize) + + /* + * NOTE: Don't truncate the range using super->total_bytes. Bytenr of + * block group is in the logical address space, which can be any + * sectorsize aligned bytenr in the range [0, U64_MAX]. + */ + if (range.len < fs_info->sb->s_blocksize) return -EINVAL;
- range.len = min(range.len, total_bytes - range.start); range.minlen = max(range.minlen, minlen); ret = btrfs_trim_fs(fs_info->tree_root, &range); if (ret < 0)