| Message ID | 20171128072039.13973-1-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 28 Nov 2017 15:20:39 +0800, Qu Wenruo wrote: > [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 get 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 sector size is valid, since btrfs use > its logical address space, there is nothing limiting the location where > we put block groups. > > For btrfs with routine 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> # v4.0+ > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > changelog: > v2: > Locate the root cause in btrfs_ioctl_fitrim(), remove the truncation > so we can still allow user to trim custom range. > v2.1: > Include the missing change in btrfs_trim_fs() and update the commit > message to reflect this. > --- > fs/btrfs/extent-tree.c | 9 +-------- > fs/btrfs/ioctl.c | 11 +++++++---- > 2 files changed, 8 insertions(+), 12 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index f830aa91ac3d..f74958e11008 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -10972,14 +10972,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) > 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); > - > + cache = btrfs_lookup_first_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); (..snip..) This first hunk should also remove total_bytes, otherwise we get an unused-variable warning: @@ -10972,19 +10972,11 @@ 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); int bg_ret = 0; int dev_ret = 0; int ret = 0; ..etc.. cheers, Holger -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index f830aa91ac3d..f74958e11008 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -10972,14 +10972,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) 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); - + cache = btrfs_lookup_first_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); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index fd172a93d11a..017fda31400d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -365,7 +365,6 @@ 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)) @@ -389,11 +388,15 @@ 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 btrfs block group is in btrfs logical address space, + * which can be any sector size aligned bytenr in [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)
[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 get 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 sector size is valid, since btrfs use its logical address space, there is nothing limiting the location where we put block groups. For btrfs with routine 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> # v4.0+ Signed-off-by: Qu Wenruo <wqu@suse.com> --- changelog: v2: Locate the root cause in btrfs_ioctl_fitrim(), remove the truncation so we can still allow user to trim custom range. v2.1: Include the missing change in btrfs_trim_fs() and update the commit message to reflect this. --- fs/btrfs/extent-tree.c | 9 +-------- fs/btrfs/ioctl.c | 11 +++++++---- 2 files changed, 8 insertions(+), 12 deletions(-)