kernel.git/fs/ceph/super.c, branch linux-4.9.y

ceph: canonicalize server path in place

2020-04-13T08:32:57Z

commit b27a939e8376a3f1ed09b9c33ef44d20f18ec3d0 upstream. syzbot reported that 4fbc0c711b24 ("ceph: remove the extra slashes in the server path") had caused a regression where an allocation could be done under a spinlock -- compare_mount_options() is called by sget_fc() with sb_lock held. We don't really need the supplied server path, so canonicalize it in place and compare it directly. To make this work, the leading slash is kept around and the logic in ceph_real_mount() to skip it is restored. CEPH_MSG_CLIENT_SESSION now reports the same (i.e. canonicalized) path, with the leading slash of course. Fixes: 4fbc0c711b24 ("ceph: remove the extra slashes in the server path") Reported-by: syzbot+98704a51af8e3d9425a9@syzkaller.appspotmail.com Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton Signed-off-by: Luis Henriques Signed-off-by: Greg Kroah-Hartman

ceph: remove the extra slashes in the server path

2020-04-13T08:32:57Z

commit 4fbc0c711b2464ee1551850b85002faae0b775d5 upstream. It's possible to pass the mount helper a server path that has more than one contiguous slash character. For example: $ mount -t ceph 192.168.195.165:40176:/// /mnt/cephfs/ In the MDS server side the extra slashes of the server path will be treated as snap dir, and then we can get the following debug logs: ceph: mount opening path // ceph: open_root_inode opening '//' ceph: fill_trace 0000000059b8a3bc is_dentry 0 is_target 1 ceph: alloc_inode 00000000dc4ca00b ceph: get_inode created new inode 00000000dc4ca00b 1.ffffffffffffffff ino 1 ceph: get_inode on 1=1.ffffffffffffffff got 00000000dc4ca00b And then when creating any new file or directory under the mount point, we can hit the following BUG_ON in ceph_fill_trace(): BUG_ON(ceph_snap(dir) != dvino.snap); Have the client ignore the extra slashes in the server path when mounting. This will also canonicalize the path, so that identical mounts can be consilidated. 1) "//mydir1///mydir//" 2) "/mydir1/mydir" 3) "/mydir1/mydir/" Regardless of the internal treatment of these paths, the kernel still stores the original string including the leading '/' for presentation to userland. URL: https://tracker.ceph.com/issues/42771 Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov Signed-off-by: Luis Henriques Signed-off-by: Greg Kroah-Hartman

ceph: flush dirty inodes before proceeding with remount

2019-05-25T16:26:49Z

commit 00abf69dd24f4444d185982379c5cc3bb7b6d1fc upstream. xfstest generic/452 was triggering a "Busy inodes after umount" warning. ceph was allowing the mount to go read-only without first flushing out dirty inodes in the cache. Ensure we sync out the filesystem before allowing a remount to proceed. Cc: stable@vger.kernel.org Link: http://tracker.ceph.com/issues/39571 Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

ceph: fix dentry leak when failing to init debugfs

2018-05-30T05:50:32Z

[ Upstream commit 18106734b512664a8541026519ce4b862498b6c3 ] When failing from ceph_fs_debugfs_init() in ceph_real_mount(), there is lack of dput of root_dentry and it causes slab errors, so change the calling order of ceph_fs_debugfs_init() and open_root_dentry() and do some cleanups to avoid this issue. Signed-off-by: Chengguang Xu Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ceph: fix uninitialized dentry pointer in ceph_real_mount()

2016-10-18T10:10:59Z

fs/ceph/super.c: In function ‘ceph_real_mount’: fs/ceph/super.c:818: warning: ‘root’ may be used uninitialized in this function If s_root is already valid, dentry pointer root is never initialized, and returned by ceph_real_mount(). This will cause a crash later when the caller dereferences the pointer. Fixes: ce2728aaa82bbeba ("ceph: avoid accessing / when mounting a subpath") Signed-off-by: Geert Uytterhoeven Signed-off-by: Yan, Zheng

ceph: avoid accessing / when mounting a subpath

2016-10-03T14:13:50Z

Accessing / causes failuire if the client has caps that restrict path Signed-off-by: Yan, Zheng

ceph: Mark the file cache as unreclaimable

2016-07-28T01:00:45Z

Ceph creates multiple caches with the SLAB_RECLAIMABLE flag set, so that it can satisfy its internal needs. Inspecting the code shows that most of the caches are indeed reclaimable since they are directly related to the generic inode/dentry shrinkers. However, one of the cache used to satisfy struct file is not reclaimable since its entries are freed only when the last reference to the file is dropped. If a heavily loaded node opens a lot of files it can introduce non-trivial discrepancies between memory shown as reclaimable and what is actually reclaimed when drop_caches is used. Fix this by removing the reclaimable flag for the file's cache. Signed-off-by: Nikolay Borisov Signed-off-by: Yan, Zheng

ceph: mount non-default filesystem by name

2016-07-28T01:00:40Z

To mount non-default filesytem, user currently needs to provide mds namespace ID. This is inconvenience. This patch makes user be able to mount filesystem by name. If user wants to mount non-default filesystem. Client first subscribes to fsmap.user. Subscribe to mdsmap. after getting ID of filesystem. Signed-off-by: Yan, Zheng

ceph: wait unsafe sync writes for evicting inode

2016-07-28T00:55:40Z

Otherwise ceph_sync_write_unsafe() may access/modify freed inode. Signed-off-by: Yan, Zheng

ceph: report mount root in session metadata

2016-05-25T23:15:33Z

Signed-off-by: Yan, Zheng