btrfs: Ensure btrfs_trim_fs can trim the whole filesystem (6ba9fc8e) · Commits · 戴 / test

[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: ("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>

fs/btrfs/extent-tree.c

+1 −9

Original line number	Diff line number	Diff line
		@@ -10851,21 +10851,13 @@ int btrfs_trim_fs(struct btrfs_fs_info fs_info, struct fstrim_range range)
		u64 start;
		u64 end;
		u64 trimmed = 0;
		u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
		u64 bg_failed = 0;
		u64 dev_failed = 0;
		int bg_ret = 0;
		int dev_ret = 0;
		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);

		for (; cache; cache = next_block_group(fs_info, cache)) {
		if (cache->key.objectid >= (range->start + range->len)) {
		btrfs_put_block_group(cache);

fs/btrfs/ioctl.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -491,7 +491,6 @@ 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))
		@@ -515,11 +514,15 @@ 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, &range);
		if (ret < 0)

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