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| author | Nikolay Borisov | 2019-06-03 12:06:01 +0200 |
|---|---|---|
| committer | David Sterba | 2019-07-01 13:35:02 +0200 |
| commit | 53460a4572585b508dc4cb6f09653ac50ba3fc49 (patch) | |
| tree | 1b4b4840274da456c3f75d27d4b7428df1c1eb0d /fs/btrfs/extent-tree.c | |
| parent | btrfs: use file:line format for assertion report (diff) | |
| download | kernel-qcow2-linux-53460a4572585b508dc4cb6f09653ac50ba3fc49.tar.gz kernel-qcow2-linux-53460a4572585b508dc4cb6f09653ac50ba3fc49.tar.xz kernel-qcow2-linux-53460a4572585b508dc4cb6f09653ac50ba3fc49.zip | |
btrfs: trim: make reserved device area adjustments more explicit
Currently the first megabyte on a device housing a btrfs filesystem is
exempt from allocation and trimming. Currently this is not a problem
since 'start' is set to 1M at the beginning of btrfs_trim_free_extents
and find_first_clear_extent_bit always returns a range that is >= start.
However, in a follow up patch find_first_clear_extent_bit will be
changed such that it will return a range containing 'start' and this
range may very well be 0...>=1M so 'start'.
Future proof the sole user of find_first_clear_extent_bit by setting
'start' after the function is called. No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/extent-tree.c')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 5d736d8ae3e3..862df2066e7a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11179,12 +11179,17 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) find_first_clear_extent_bit(&device->alloc_state, start, &start, &end, CHUNK_TRIMMED | CHUNK_ALLOCATED); + + /* Ensure we skip the reserved area in the first 1M */ + start = max_t(u64, start, SZ_1M); + /* * If find_first_clear_extent_bit find a range that spans the * end of the device it will set end to -1, in this case it's up * to the caller to trim the value to the size of the device. */ end = min(end, device->total_bytes - 1); + len = end - start + 1; /* We didn't find any extents */ |