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authorYan, Zheng <zyan@redhat.com>2017-08-04 11:22:31 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-07 08:34:09 +0200
commit857d0b3dd7566ebb70686a009c7100322ddf3bbe (patch)
tree0bfda01d6493f4a8243cf638a501b2fa7a82aa95
parent043ccc9781cc2e2914253c1c6f17923905c83a4e (diff)
downloadlinux-linaro-stable-857d0b3dd7566ebb70686a009c7100322ddf3bbe.tar.gz
ceph: fix readpage from fscache
commit dd2bc473482eedc60c29cf00ad12568ce40ce511 upstream. 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() Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/ceph/addr.c24
-rw-r--r--fs/ceph/cache.c12
2 files changed, 18 insertions, 18 deletions
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index c6a1ec110c01..22bae2b434e2 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;
}
@@ -1094,7 +1097,7 @@ retry_locked:
goto retry_locked;
r = writepage_nounlock(page, NULL);
if (r < 0)
- goto fail_nosnap;
+ goto fail_unlock;
goto retry_locked;
}
@@ -1122,11 +1125,14 @@ 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 a4766ded1ba7..ff1cfd7b1083 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -224,13 +224,7 @@ void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
fscache_relinquish_cookie(cookie, 0);
}
-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);
@@ -259,7 +253,7 @@ 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) {
@@ -288,7 +282,7 @@ 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) {