locking rules:
All except set_page_dirty may block
- BKL PageLocked(page) i_sem
+ BKL PageLocked(page) i_mutex
writepage: no yes, unlocks (see below)
readpage: no yes, unlocks
sync_page: no maybe
implementations. If your fs is not using generic_file_llseek, you
need to acquire and release the appropriate locks in your ->llseek().
For many filesystems, it is probably safe to acquire the inode
-semaphore. Note some filesystems (i.e. remote ones) provide no
+mutex. Note some filesystems (i.e. remote ones) provide no
protection for i_size so you will need to use the BKL.
Note: ext2_release() was *the* source of contention on fs-intensive