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authorEric Paris <eparis@redhat.com>2009-05-21 17:01:58 -0400
committerEric Paris <eparis@redhat.com>2009-06-11 14:57:54 -0400
commit164bc6195139047faaf5ada1278332e99494803b (patch)
treefdc0e31f9dc15796a4777ed917533091797b8b69 /fs/notify/inode_mark.c
parent1ef5f13c6c8acd3fd10db9f1743f3b4cf30a4abb (diff)
fsnotify: handle filesystem unmounts with fsnotify marks
When an fs is unmounted with an fsnotify mark entry attached to one of its inodes we need to destroy that mark entry and we also (like inotify) send an unmount event. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/notify/inode_mark.c')
-rw-r--r--fs/notify/inode_mark.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 282150f74cf..0a499d2c619 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -89,6 +89,7 @@
89#include <linux/mutex.h> 89#include <linux/mutex.h>
90#include <linux/slab.h> 90#include <linux/slab.h>
91#include <linux/spinlock.h> 91#include <linux/spinlock.h>
92#include <linux/writeback.h> /* for inode_lock */
92 93
93#include <asm/atomic.h> 94#include <asm/atomic.h>
94 95
@@ -351,3 +352,74 @@ int fsnotify_add_mark(struct fsnotify_mark_entry *entry,
351 352
352 return ret; 353 return ret;
353} 354}
355
356/**
357 * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
358 * @list: list of inodes being unmounted (sb->s_inodes)
359 *
360 * Called with inode_lock held, protecting the unmounting super block's list
361 * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
362 * We temporarily drop inode_lock, however, and CAN block.
363 */
364void fsnotify_unmount_inodes(struct list_head *list)
365{
366 struct inode *inode, *next_i, *need_iput = NULL;
367
368 list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
369 struct inode *need_iput_tmp;
370
371 /*
372 * We cannot __iget() an inode in state I_CLEAR, I_FREEING,
373 * I_WILL_FREE, or I_NEW which is fine because by that point
374 * the inode cannot have any associated watches.
375 */
376 if (inode->i_state & (I_CLEAR|I_FREEING|I_WILL_FREE|I_NEW))
377 continue;
378
379 /*
380 * If i_count is zero, the inode cannot have any watches and
381 * doing an __iget/iput with MS_ACTIVE clear would actually
382 * evict all inodes with zero i_count from icache which is
383 * unnecessarily violent and may in fact be illegal to do.
384 */
385 if (!atomic_read(&inode->i_count))
386 continue;
387
388 need_iput_tmp = need_iput;
389 need_iput = NULL;
390
391 /* In case fsnotify_inode_delete() drops a reference. */
392 if (inode != need_iput_tmp)
393 __iget(inode);
394 else
395 need_iput_tmp = NULL;
396
397 /* In case the dropping of a reference would nuke next_i. */
398 if ((&next_i->i_sb_list != list) &&
399 atomic_read(&next_i->i_count) &&
400 !(next_i->i_state & (I_CLEAR | I_FREEING | I_WILL_FREE))) {
401 __iget(next_i);
402 need_iput = next_i;
403 }
404
405 /*
406 * We can safely drop inode_lock here because we hold
407 * references on both inode and next_i. Also no new inodes
408 * will be added since the umount has begun. Finally,
409 * iprune_mutex keeps shrink_icache_memory() away.
410 */
411 spin_unlock(&inode_lock);
412
413 if (need_iput_tmp)
414 iput(need_iput_tmp);
415
416 /* for each watch, send FS_UNMOUNT and then remove it */
417 fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
418
419 fsnotify_inode_delete(inode);
420
421 iput(inode);
422
423 spin_lock(&inode_lock);
424 }
425}