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| author |   Jeff Layton <jlayton@kernel.org> | 2021-03-23 15:16:52 -0400 |
|---|---|---|
| committer |   Ilya Dryomov <idryomov@gmail.com> | 2021-04-27 23:52:23 +0200 |
| commit | 379fc7fad0ae6ed5ceefd39b8a7a37e83a63c25e (patch) | |
| tree | 30da2f83e21b62789377f3d1aaa83c0997c668e1 /fs/ceph | |
| parent | ceph: don't use d_add in ceph_handle_snapdir (diff) | |
| download | linux-dev-379fc7fad0ae6ed5ceefd39b8a7a37e83a63c25e.tar.xz linux-dev-379fc7fad0ae6ed5ceefd39b8a7a37e83a63c25e.zip | |
ceph: use attach/detach_page_private for tracking snap context
There is some ambiguity around the use of PagePrivate. It's
generally expected in core code that if PagePrivate is set then
you have a reference to it. It's not clear that ceph always
does (and I believe it may not).
Change ceph to use attach/detach_page_private so that we keep a
reference to the page until the snap context is detached.
Link: https://lore.kernel.org/ceph-devel/2503810.1616508988@warthog.procyon.org.uk/T/#mf29e5abbb0ec8035cde0de30778690de7d956f84
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph')
| -rw-r--r-- | fs/ceph/addr.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index cb88ba91b671..72c0901b6d15 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -128,8 +128,7 @@ static int ceph_set_page_dirty(struct page *page) * PagePrivate so that we get invalidatepage callback. */ BUG_ON(PagePrivate(page)); - page->private = (unsigned long)snapc; - SetPagePrivate(page); + attach_page_private(page, snapc); ret = __set_page_dirty_nobuffers(page); WARN_ON(!PageLocked(page)); @@ -148,7 +147,7 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset, { struct inode *inode; struct ceph_inode_info *ci; - struct ceph_snap_context *snapc = page_snap_context(page); + struct ceph_snap_context *snapc; wait_on_page_fscache(page); @@ -168,10 +167,9 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset, dout("%p invalidatepage %p idx %lu full dirty page\n", inode, page, page->index); + snapc = detach_page_private(page); ceph_put_wrbuffer_cap_refs(ci, 1, snapc); ceph_put_snap_context(snapc); - page->private = 0; - ClearPagePrivate(page); } static int ceph_releasepage(struct page *page, gfp_t gfp) @@ -589,8 +587,8 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc) dout("writepage cleaned page %p\n", page); err = 0; /* vfs expects us to return 0 */ } - page->private = 0; - ClearPagePrivate(page); + oldest = detach_page_private(page); + WARN_ON_ONCE(oldest != snapc); end_page_writeback(page); ceph_put_wrbuffer_cap_refs(ci, 1, snapc); ceph_put_snap_context(snapc); /* page's reference */ @@ -682,11 +680,9 @@ static void writepages_finish(struct ceph_osd_request *req) clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC); - ceph_put_snap_context(page_snap_context(page)); - page->private = 0; - ClearPagePrivate(page); - dout("unlocking %p\n", page); + ceph_put_snap_context(detach_page_private(page)); end_page_writeback(page); + dout("unlocking %p\n", page); if (remove_page) generic_error_remove_page(inode->i_mapping, |