prototypes:
struct inode *(*alloc_inode)(struct super_block *sb);
void (*destroy_inode)(struct inode *);
- void (*read_inode) (struct inode *);
void (*dirty_inode) (struct inode *);
int (*write_inode) (struct inode *, int);
void (*put_inode) (struct inode *);
BKL s_lock s_umount
alloc_inode: no no no
destroy_inode: no
-read_inode: no (see below)
dirty_inode: no (must not sleep)
write_inode: no
put_inode: no
quota_read: no no no (see below)
quota_write: no no no (see below)
-->read_inode() is not a method - it's a callback used in iget().
->remount_fs() will have the s_umount lock if it's already mounted.
When called from get_sb_single, it does NOT have the s_umount lock.
->quota_read() and ->quota_write() functions are both guaranteed to
locking rules:
All except set_page_dirty may block
- BKL PageLocked(page)
+ BKL PageLocked(page) i_sem
writepage: no yes, unlocks (see below)
readpage: no yes, unlocks
sync_page: no maybe
writepages: no
set_page_dirty no no
readpages: no
-prepare_write: no yes
-commit_write: no yes
+prepare_write: no yes yes
+commit_write: no yes yes
+write_begin: no locks the page yes
+write_end: no yes, unlocks yes
+perform_write: no n/a yes
bmap: yes
invalidatepage: no yes
releasepage: no yes
redirty_page_for_writepage(), then unlock the page and return zero.
This may also be done to avoid internal deadlocks, but rarely.
-If the filesytem is called for sync then it must wait on any
+If the filesystem is called for sync then it must wait on any
in-progress I/O and then start new I/O.
The filesystem should unlock the page synchronously, before returning to the