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| author | Boris Burkov <boris@bur.io> | 2020-11-18 15:06:22 -0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2020-12-09 19:16:08 +0100 |
| commit | 948462294577a3870c407c16d89bb2314f0b0cfb (patch) | |
| tree | 3ef24bbc5ecac9ddc42ea657752d01c6de81947c /fs/btrfs/disk-io.c | |
| parent | 8b228324a8ce03083a034dfa784bc10696ce7489 (diff) | |
| download | linux-948462294577a3870c407c16d89bb2314f0b0cfb.tar.bz2 | |
btrfs: keep sb cache_generation consistent with space_cache
When mounting, btrfs uses the cache_generation in the super block to
determine if space cache v1 is in use. However, by mounting with
nospace_cache or space_cache=v2, it is possible to disable space cache
v1, which does not result in un-setting cache_generation back to 0.
In order to base some logic, like mount option printing in /proc/mounts,
on the current state of the space cache rather than just the values of
the mount option, keep the value of cache_generation consistent with the
status of space cache v1.
We ensure that cache_generation > 0 iff the file system is using
space_cache v1. This requires committing a transaction on any mount
which changes whether we are using v1. (v1->nospace_cache, v1->v2,
nospace_cache->v1, v2->v1).
Since the mechanism for writing out the cache generation is transaction
commit, but we want some finer grained control over when we un-set it,
we can't just rely on the SPACE_CACHE mount option, and introduce an
fs_info flag that mount can use when it wants to unset the generation.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 77c7013f69d7..2dcc5e52140c 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2888,6 +2888,7 @@ void btrfs_clear_oneshot_options(struct btrfs_fs_info *fs_info) int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info) { int ret; + const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE); bool clear_free_space_tree = false; if (btrfs_test_opt(fs_info, CLEAR_CACHE) && @@ -2940,6 +2941,12 @@ int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info) } } + if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) { + ret = btrfs_set_free_space_cache_v1_active(fs_info, cache_opt); + if (ret) + goto out; + } + ret = btrfs_resume_balance_async(fs_info); if (ret) goto out; @@ -3410,6 +3417,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device return ret; } } + set_bit(BTRFS_FS_OPEN, &fs_info->flags); clear_oneshot: |