From dd2bc473482eedc60c29cf00ad12568ce40ce511 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Fri, 4 Aug 2017 11:22:31 +0800 Subject: [PATCH] ceph: fix readpage from fscache ceph_readpage() unlocks page prematurely prematurely in the case that page is reading from fscache. Caller of readpage expects that page is uptodate when it get unlocked. So page shoule get locked by completion callback of fscache_read_or_alloc_pages() Cc: stable@vger.kernel.org # 4.1+, needs backporting for < 4.7 Signed-off-by: "Yan, Zheng" Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- fs/ceph/addr.c | 24 +++++++++++++++--------- fs/ceph/cache.c | 12 +++--------- 2 files changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 5083628..1bc709f 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -189,7 +189,7 @@ static int ceph_releasepage(struct page *page, gfp_t g) /* * read a single page, without unlocking it. */ -static int readpage_nounlock(struct file *filp, struct page *page) +static int ceph_do_readpage(struct file *filp, struct page *page) { struct inode *inode = file_inode(filp); struct ceph_inode_info *ci = ceph_inode(inode); @@ -219,7 +219,7 @@ static int readpage_nounlock(struct file *filp, struct page *page) err = ceph_readpage_from_fscache(inode, page); if (err == 0) - goto out; + return -EINPROGRESS; dout("readpage inode %p file %p page %p index %lu\n", inode, filp, page, page->index); @@ -249,8 +249,11 @@ out: static int ceph_readpage(struct file *filp, struct page *page) { - int r = readpage_nounlock(filp, page); - unlock_page(page); + int r = ceph_do_readpage(filp, page); + if (r != -EINPROGRESS) + unlock_page(page); + else + r = 0; return r; } @@ -1237,7 +1240,7 @@ retry_locked: goto retry_locked; r = writepage_nounlock(page, NULL); if (r < 0) - goto fail_nosnap; + goto fail_unlock; goto retry_locked; } @@ -1265,11 +1268,14 @@ retry_locked: } /* we need to read it. */ - r = readpage_nounlock(file, page); - if (r < 0) - goto fail_nosnap; + r = ceph_do_readpage(file, page); + if (r < 0) { + if (r == -EINPROGRESS) + return -EAGAIN; + goto fail_unlock; + } goto retry_locked; -fail_nosnap: +fail_unlock: unlock_page(page); return r; } diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c index fd11728..337f886 100644 --- a/fs/ceph/cache.c +++ b/fs/ceph/cache.c @@ -297,13 +297,7 @@ void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp) } } -static void ceph_vfs_readpage_complete(struct page *page, void *data, int error) -{ - if (!error) - SetPageUptodate(page); -} - -static void ceph_vfs_readpage_complete_unlock(struct page *page, void *data, int error) +static void ceph_readpage_from_fscache_complete(struct page *page, void *data, int error) { if (!error) SetPageUptodate(page); @@ -331,7 +325,7 @@ int ceph_readpage_from_fscache(struct inode *inode, struct page *page) return -ENOBUFS; ret = fscache_read_or_alloc_page(ci->fscache, page, - ceph_vfs_readpage_complete, NULL, + ceph_readpage_from_fscache_complete, NULL, GFP_KERNEL); switch (ret) { @@ -360,7 +354,7 @@ int ceph_readpages_from_fscache(struct inode *inode, return -ENOBUFS; ret = fscache_read_or_alloc_pages(ci->fscache, mapping, pages, nr_pages, - ceph_vfs_readpage_complete_unlock, + ceph_readpage_from_fscache_complete, NULL, mapping_gfp_mask(mapping)); switch (ret) { -- 2.7.4