diff options
Diffstat (limited to 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index f8c9e5eb4685..7be23ff20b27 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -207,6 +207,15 @@ __find_get_block_slow(struct block_device *bdev, sector_t block, bool atomic) head = folio_buffers(folio); if (!head) goto out_unlock; + /* + * Upon a noref migration, the folio lock serializes here; + * otherwise bail. + */ + if (test_bit_acquire(BH_Migrate, &head->b_state)) { + WARN_ON(!atomic); + goto out_unlock; + } + bh = head; do { if (!buffer_mapped(bh)) @@ -1390,7 +1399,8 @@ lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size) /* * Perform a pagecache lookup for the matching buffer. If it's there, refresh * it in the LRU and mark it as accessed. If it is not present then return - * NULL + * NULL. Atomic context callers may also return NULL if the buffer is being + * migrated; similarly the page is not marked accessed either. */ static struct buffer_head * find_get_block_common(struct block_device *bdev, sector_t block, |