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ceph: fix snap context reference leaks

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The get_oldest_context() helper takes a reference to the returned snap
context, but most callers weren't dropping that reference.  Fix them.

Also drop the unused locked __get_oldest_context() variant.

Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Sage Weil 2010-03-31 22:01:38 -07:00
parent 80e755fede
commit 6298a33757
1 changed files with 17 additions and 20 deletions
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37
fs/ceph/addr.c
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@ -336,16 +336,15 @@ static int ceph_readpages(struct file *file, struct address_space *mapping,
/*
* Get ref for the oldest snapc for an inode with dirty data... that is, the
* only snap context we are allowed to write back.
*
* Caller holds i_lock.
*/
static struct ceph_snap_context *__get_oldest_context(struct inode *inode,
u64 *snap_size)
static struct ceph_snap_context *get_oldest_context(struct inode *inode,
u64 *snap_size)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_snap_context *snapc = NULL;
struct ceph_cap_snap *capsnap = NULL;
spin_lock(&inode->i_lock);
list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
capsnap->context, capsnap->dirty_pages);
@ -361,16 +360,6 @@ static struct ceph_snap_context *__get_oldest_context(struct inode *inode,
dout(" head snapc %p has %d dirty pages\n",
snapc, ci->i_wrbuffer_ref_head);
}
return snapc;
}
static struct ceph_snap_context *get_oldest_context(struct inode *inode,
u64 *snap_size)
{
struct ceph_snap_context *snapc = NULL;
spin_lock(&inode->i_lock);
snapc = __get_oldest_context(inode, snap_size);
spin_unlock(&inode->i_lock);
return snapc;
}
@ -391,7 +380,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
int len = PAGE_CACHE_SIZE;
loff_t i_size;
int err = 0;
struct ceph_snap_context *snapc;
struct ceph_snap_context *snapc, *oldest;
u64 snap_size = 0;
long writeback_stat;
@ -412,13 +401,16 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
dout("writepage %p page %p not dirty?\n", inode, page);
goto out;
}
if (snapc->seq > get_oldest_context(inode, &snap_size)->seq) {
oldest = get_oldest_context(inode, &snap_size);
if (snapc->seq > oldest->seq) {
dout("writepage %p page %p snapc %p not writeable - noop\n",
inode, page, (void *)page->private);
/* we should only noop if called by kswapd */
WARN_ON((current->flags & PF_MEMALLOC) == 0);
ceph_put_snap_context(oldest);
goto out;
}
ceph_put_snap_context(oldest);
/* is this a partial page at end of file? */
if (snap_size)
@ -457,7 +449,7 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
ClearPagePrivate(page);
end_page_writeback(page);
ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
ceph_put_snap_context(snapc);
ceph_put_snap_context(snapc); /* page's reference */
out:
return err;
}
@ -914,7 +906,10 @@ static int context_is_writeable_or_written(struct inode *inode,
struct ceph_snap_context *snapc)
{
struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
return !oldest || snapc->seq <= oldest->seq;
int ret = !oldest || snapc->seq <= oldest->seq;
ceph_put_snap_context(oldest);
return ret;
}
/*
@ -957,13 +952,14 @@ static int ceph_update_writeable_page(struct file *file,
up_read(&mdsc->snap_rwsem);
if (snapc->seq > oldest->seq) {
ceph_put_snap_context(oldest);
dout(" page %p snapc %p not current or oldest\n",
page, (void *)page->private);
page, snapc);
/*
* queue for writeback, and wait for snapc to
* be writeable or written
*/
snapc = ceph_get_snap_context((void *)page->private);
snapc = ceph_get_snap_context(snapc);
unlock_page(page);
ceph_queue_writeback(inode);
r = wait_event_interruptible(ci->i_cap_wq,
@ -973,6 +969,7 @@ static int ceph_update_writeable_page(struct file *file,
return r;
return -EAGAIN;
}
ceph_put_snap_context(oldest);
/* yay, writeable, do it now (without dropping page lock) */
dout(" page %p snapc %p not current, but oldest\n",