diff options
Diffstat (limited to 'block/bdev.c')
| -rw-r--r-- | block/bdev.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/block/bdev.c b/block/bdev.c index 738e3c8457e7..e7daca6565ea 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -168,9 +168,26 @@ int set_blocksize(struct file *file, int size) /* Don't change the size if it is same as current */ if (inode->i_blkbits != blksize_bits(size)) { + /* + * Flush and truncate the pagecache before we reconfigure the + * mapping geometry because folio sizes are variable now. If a + * reader has already allocated a folio whose size is smaller + * than the new min_order but invokes readahead after the new + * min_order becomes visible, readahead will think there are + * "zero" blocks per folio and crash. Take the inode and + * invalidation locks to avoid racing with + * read/write/fallocate. + */ + inode_lock(inode); + filemap_invalidate_lock(inode->i_mapping); + sync_blockdev(bdev); + kill_bdev(bdev); + inode->i_blkbits = blksize_bits(size); kill_bdev(bdev); + filemap_invalidate_unlock(inode->i_mapping); + inode_unlock(inode); } return 0; } |