kernel/git/stable/linux-stable.git/fs/nfs, branch linux-3.2.y

fs: Teach path_connected to handle nfs filesystems with multiple roots.

2018-05-31T23:30:22+00:00

commit 95dd77580ccd66a0da96e6d4696945b8cea39431 upstream. On nfsv2 and nfsv3 the nfs server can export subsets of the same filesystem and report the same filesystem identifier, so that the nfs client can know they are the same filesystem. The subsets can be from disjoint directory trees. The nfsv2 and nfsv3 filesystems provides no way to find the common root of all directory trees exported form the server with the same filesystem identifier. The practical result is that in struct super s_root for nfs s_root is not necessarily the root of the filesystem. The nfs mount code sets s_root to the root of the first subset of the nfs filesystem that the kernel mounts. This effects the dcache invalidation code in generic_shutdown_super currently called shrunk_dcache_for_umount and that code for years has gone through an additional list of dentries that might be dentry trees that need to be freed to accomodate nfs. When I wrote path_connected I did not realize nfs was so special, and it's hueristic for avoiding calling is_subdir can fail. The practical case where this fails is when there is a move of a directory from the subtree exposed by one nfs mount to the subtree exposed by another nfs mount. This move can happen either locally or remotely. With the remote case requiring that the move directory be cached before the move and that after the move someone walks the path to where the move directory now exists and in so doing causes the already cached directory to be moved in the dcache through the magic of d_splice_alias. If someone whose working directory is in the move directory or a subdirectory and now starts calling .. from the initial mount of nfs (where s_root == mnt_root), then path_connected as a heuristic will not bother with the is_subdir check. As s_root really is not the root of the nfs filesystem this heuristic is wrong, and the path may actually not be connected and path_connected can fail. The is_subdir function might be cheap enough that we can call it unconditionally. Verifying that will take some benchmarking and the result may not be the same on all kernels this fix needs to be backported to. So I am avoiding that for now. Filesystems with snapshots such as nilfs and btrfs do something similar. But as the directory tree of the snapshots are disjoint from one another and from the main directory tree rename won't move things between them and this problem will not occur. Reported-by: Al Viro Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" Signed-off-by: Al Viro [bwh: Backported to 3.2: - Add the super_block::s_iflags field - Adjust context] Signed-off-by: Ben Hutchings

nfs: Fix ugly referral attributes

2018-02-13T18:32:18+00:00

commit c05cefcc72416a37eba5a2b35f0704ed758a9145 upstream. Before traversing a referral and performing a mount, the mounted-on directory looks strange: dr-xr-xr-x. 2 4294967294 4294967294 0 Dec 31 1969 dir.0 nfs4_get_referral is wiping out any cached attributes with what was returned via GETATTR(fs_locations), but the bit mask for that operation does not request any file attributes. Retrieve owner and timestamp information so that the memcpy in nfs4_get_referral fills in more attributes. Changes since v1: - Don't request attributes that the client unconditionally replaces - Request only MOUNTED_ON_FILEID or FILEID attribute, not both - encode_fs_locations() doesn't use the third bitmask word Fixes: 6b97fd3da1ea ("NFSv4: Follow a referral") Suggested-by: Pradeep Thomas Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

mount: copy the port field into the cloned nfs_server structure.

2017-11-11T13:34:24+00:00

commit 89a6814d9b665b196aa3a102f96b6dc7e8cb669e upstream. Doing this copy eliminates the "port=0" entry in the /proc/mounts entries Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=69241 Signed-off-by: Steve Dickson Signed-off-by: Anna Schumaker [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

NFSv4: fix getacl ERANGE for some ACL buffer sizes

2017-06-05T20:13:51+00:00

commit ed92d8c137b7794c2c2aa14479298b9885967607 upstream. We're not taking into account that the space needed for the (variable length) attr bitmap, with the result that we'd sometimes get a spurious ERANGE when the ACL data got close to the end of a page. Just add in an extra page to make sure. Signed-off-by: Weston Andros Adamson Signed-off-by: J. Bruce Fields Signed-off-by: Anna Schumaker [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

NFSv4: Fix range checking in __nfs4_get_acl_uncached and __nfs4_proc_set_acl

2017-06-05T20:13:51+00:00

commit 21f498c2f73bd6150d82931f09965826dca0b5f2 upstream. Ensure that the user supplied buffer size doesn't cause us to overflow the 'pages' array. Also fix up some confusion between the use of PAGE_SIZE and PAGE_CACHE_SIZE when calculating buffer sizes. We're not using the page cache for anything here. Signed-off-by: Trond Myklebust Signed-off-by: Ben Hutchings

NFSv4: Fix the underestimation of delegation XDR space reservation

2017-06-05T20:13:50+00:00

commit 5a1f6d9e9b803003271b40b67786ff46fa4eda01 upstream. Account for the "space_limit" field in struct open_write_delegation4. Fixes: 2cebf82883f4 ("NFSv4: Fix the underestimate of NFSv4 open request size") Signed-off-by: Trond Myklebust Reviewed-by: Chuck Lever Signed-off-by: Anna Schumaker Signed-off-by: Ben Hutchings

nfs_write_end(): fix handling of short copies

2017-03-16T02:18:30+00:00

commit c0cf3ef5e0f47e385920450b245d22bead93e7ad upstream. What matters when deciding if we should make a page uptodate is not how much we _wanted_ to copy, but how much we actually have copied. As it is, on architectures that do not zero tail on short copy we can leave uninitialized data in page marked uptodate. Signed-off-by: Al Viro Signed-off-by: Ben Hutchings

NFSv4: Open state recovery must account for file permission changes

2017-02-23T03:50:51+00:00

commit 304020fe48c6c7fff8b5a38f382b54404f0f79d3 upstream. If the file permissions change on the server, then we may not be able to recover open state. If so, we need to ensure that we mark the file descriptor appropriately. Signed-off-by: Trond Myklebust Tested-by: Oleg Drokin Signed-off-by: Anna Schumaker Signed-off-by: Ben Hutchings

NFSv4.1: Fix the CREATE_SESSION slot number accounting

2016-11-20T01:01:37+00:00

commit b519d408ea32040b1c7e10b155a3ee9a36660947 upstream. Ensure that we conform to the algorithm described in RFC5661, section 18.36.4 for when to bump the sequence id. In essence we do it for all cases except when the RPC call timed out, or in case of the server returning NFS4ERR_DELAY or NFS4ERR_STALE_CLIENTID. Signed-off-by: Trond Myklebust [bwh: Backported to 3.2: - Add the 'out' label - Adjust context] Signed-off-by: Ben Hutchings

nfs: don't create zero-length requests

2016-11-20T01:01:28+00:00

commit 149a4fddd0a72d526abbeac0c8deaab03559836a upstream. NFS doesn't expect requests with wb_bytes set to zero and may make unexpected decisions about how to handle that request at the page IO layer. Skip request creation if we won't have any wb_bytes in the request. Signed-off-by: Benjamin Coddington Signed-off-by: Alexey Dobriyan Reviewed-by: Weston Andros Adamson Signed-off-by: Trond Myklebust [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings