fs: Teach path_connected to handle nfs filesystems with multiple roots. 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 <viro@ZenIV.linux.org.uk> Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.2: - Add the super_block::s_iflags field - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nfs: fix null checking in nfs_get_option_str() commit e25fbe380c4e3c09afa98bcdcd9d3921443adab8 upstream. The following null pointer check is broken. *option = match_strdup(args); return !option; The pointer `option' must be non-null, and thus `!option' is always false. Use `!*option' instead. The bug was introduced in commit c5cb09b6f8 ("Cleanup: Factor out some cut-and-paste code."). Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nfs: Show original device name verbatim in /proc/*/mount{s,info} commit 97a54868262da1629a3e65121e65b8e8c4419d9f upstream. Since commit c7f404b ('vfs: new superblock methods to override /proc/*/mount{s,info}'), nfs_path() is used to generate the mounted device name reported back to userland. nfs_path() always generates a trailing slash when the given dentry is the root of an NFS mount, but userland may expect the original device name to be returned verbatim (as it used to be). Make this canonicalisation optional and change the callers accordingly. [jrnieder@gmail.com: use flag instead of bool argument] Reported-and-tested-by: Chris Hiestand <chiestand@salk.edu> Reference: http://bugs.debian.org/669314 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> [bwh: Backported to 3.2: - Adjust context - nfs_show_devname() still takes a pointer to struct vfsmount]
NFS: Fix a problem with the legacy binary mount code commit 872ece86ea5c367aa92f44689c2d01a1c767aeb3 upstream. Apparently, am-utils is still using the legacy binary mountdata interface, and is having trouble parsing /proc/mounts due to the 'port=' field being incorrectly set. The following patch should fix up the regression. Reported-by: Marius Tolzmann <tolzmann@molgen.mpg.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
NFS: Alias the nfs module to nfs4 commit 425e776d93a7a5070b77d4f458a5bab0f924652c upstream. This allows distros to remove the line from their modprobe configuration. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nfs: Enclose hostname in brackets when needed in nfs_do_root_mount commit 98a2139f4f4d7b5fcc3a54c7fddbe88612abed20 upstream. When hostname contains colon (e.g. when it is an IPv6 address) it needs to be enclosed in brackets to make parsing of NFS device string possible. Fix nfs_do_root_mount() to enclose hostname properly when needed. NFS code actually does not need this as it does not parse the string passed by nfs_do_root_mount() but the device string is exposed to userspace in /proc/mounts. CC: Josh Boyer <jwboyer@redhat.com> CC: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nfs: fix regression in handling of context= option in NFSv4 commit 8a0d551a59ac92d8ff048d6cb29d3a02073e81e8 upstream. Setting the security context of a NFSv4 mount via the context= mount option is currently broken. The NFSv4 codepath allocates a parsed options struct, and then parses the mount options to fill it. It eventually calls nfs4_remote_mount which calls security_init_mnt_opts. That clobbers the lsm_opts struct that was populated earlier. This bug also looks like it causes a small memory leak on each v4 mount where context= is used. Fix this by moving the initialization of the lsm_opts into nfs_alloc_parsed_mount_data. Also, add a destructor for nfs_parsed_mount_data to make it easier to free all of the allocations hanging off of it, and to ensure that the security_free_mnt_opts is called whenever security_init_mnt_opts is. I believe this regression was introduced quite some time ago, probably by commit c02d7adf. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
new helper: mount_subtree() takes vfsmount and relative path, does lookup within that vfsmount (possibly triggering automounts) and returns the result as root of subtree suitable for return by ->mount() (i.e. a reference to dentry and an active reference to its superblock grabbed, superblock locked exclusive). btrfs and nfs switched to it instead of open-coding the sucker. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch create_mnt_ns() to saner calling conventions, fix double mntput() in nfs Life is much saner if create_mnt_ns(mnt) drops mnt in case of error... Switch it to such calling conventions, switch callers, fix double mntput() in fs/nfs/super.c one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
nfs/super.c: local functions should be static commit ae50c0b5 "pnfs: client stats" added additional information to the output of /proc/self/mountstats. The new functions introduced are only used in this file and should be marked static. If CONFIG_NFS_V4_1 is not defined, empty stub functions are used. If CONFIG_NFS_V4 is not defined these stub functions are not used at all. Adding static for the functions results in compile warnings: fs/nfs/super.c:743: warning: 'show_sessions' defined but not used fs/nfs/super.c:756: warning: 'show_pnfs' defined but not used Fix this by adding a #ifdef CONFIG_NFS_V4 guard around the two show_ functions. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
VFS: Fix the remaining automounter semantics regressions The concensus seems to be that system calls such as stat() etc should not trigger an automount. Neither should the l* versions. This patch therefore adds a LOOKUP_AUTOMOUNT flag to tag those lookups that _should_ trigger an automount on the last path element. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> [ Edited to leave out the cases that are already covered by LOOKUP_OPEN, LOOKUP_DIRECTORY and LOOKUP_CREATE - all of which also fundamentally force automounting for their own reasons - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nfs: Do not allow multiple mounts on same mountpoint when using -o noac Do not allow multiple mounts on same mountpoint when using -o noac When you normally attempt to mount a share twice on the same mountpoint, a check in do_add_mount causes it to return an error # mount localhost:/nfsv3 /mnt # mount localhost:/nfsv3 /mnt mount.nfs: /mnt is already mounted or busy However when using the option 'noac', the user is able to mount the same share on the same mountpoint multiple times. This happens because a share mounted with the noac option is automatically assigned the 'sync' flag MS_SYNCHRONOUS in nfs_initialise_sb(). This flag is set after the check for already existing superblocks is done in sget(). The check for the mount flags in nfs_compare_mount_options() does not take into account the 'sync' flag applied later on in the code path. This means that when using 'noac', a new superblock structure is assigned for every new mount of the same share and multiple shares on the same mountpoint are allowed. ie. # mount -onoac localhost:/nfsv3 /mnt can be run multiple times. The patch checks for noac and assigns the sync flag before sget() is called to obtain an already existing superblock structure. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
switch vfs_path_lookup() to struct path Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pnfs: client stats A pNFS client auto-negotiates a lot of features (minorversion level, pNFS layout type, etc.). This is convenient, but makes certain kinds of failures hard for a user to detect. For example, if the client falls back on 4.0, or falls back to MDS IO because the user didn't connect to the right iscsi disks before mounting, the only symptoms may be reduced performance, which may not be noticed till long after the actual failure, and may be difficult for a user to diagnose. However, such "failures" may also be perfectly normal in some cases, so we don't want to spam the system logs with them. One approach would be to put some more information into /proc/self/mountstats. Signed-off-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [pnfs: add commit client stats] [fixup data types for "ret" variables in pnfs_try_to* inline funcs.] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [fix definition of show_pnfs for !CONFIG_PNFS] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Fix show_sessions in the not CONFIG_NFS_V4_1 case] There is a build error when CONFIG_NFS_V4 is set but CONFIG_NFS_V4_1 is *not* set. show_sessions() prototype was unbalanced between the two cases. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> [pnfs: super.c remove CONFIG_PNFS] Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
nfs: don't lose MS_SYNCHRONOUS on remount of noac mount On a remount, the VFS layer will clear the MS_SYNCHRONOUS bit on the assumption that the flags on the mount syscall will have it set if the remounted fs is supposed to keep it. In the case of "noac" though, MS_SYNCHRONOUS is implied. A remount of such a mount will lose the MS_SYNCHRONOUS flag since "sync" isn't part of the mount options. Reported-by: Max Matveev <makc@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: stable@kernel.org Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: don't negotiate when user specifies sec flavor We were always attempting sec flavor negotiation, even if the user told us a specific sec flavor to use. If that sec flavor fails, we should return an error rather than continuing with sec flavor negotiation. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS: Remove dead code from nfs_fs_mount() In fs/nfs/super.c::nfs_fs_mount() we test for a NULL 'data': ... if (data == NULL || mntfh == NULL) goto out_free_fh; ... and then further down in the function we test 'data' again: ... nfs_fscache_get_super_cookie( s, data ? data->fscache_uniq : NULL, NULL); ... this second check is just dead code since there is no way 'data' could possibly be NULL here. We also rely on a non-NULL 'data' in more than one location between these two tests, further proving the point that the second test is bogus. This patch removes the dead code. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Merge branch 'nfs-for-2.6.39' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 * 'nfs-for-2.6.39' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (54 commits) RPC: killing RPC tasks races fixed xprt: remove redundant check SUNRPC: Convert struct rpc_xprt to use atomic_t counters SUNRPC: Ensure we always run the tk_callback before tk_action sunrpc: fix printk format warning xprt: remove redundant null check nfs: BKL is no longer needed, so remove the include NFS: Fix a warning in fs/nfs/idmap.c Cleanup: Factor out some cut-and-paste code. cleanup: save 60 lines/100 bytes by combining two mostly duplicate functions. NFS: account direct-io into task io accounting gss:krb5 only include enctype numbers in gm_upcall_enctypes RPCRDMA: Fix FRMR registration/invalidate handling. RPCRDMA: Fix to XDR page base interpretation in marshalling logic. NFSv4: Send unmapped uid/gids to the server when using auth_sys NFSv4: Propagate the error NFS4ERR_BADOWNER to nfs4_do_setattr NFSv4: cleanup idmapper functions to take an nfs_server argument NFSv4: Send unmapped uid/gids to the server if the idmapper fails NFSv4: If the server sends us a numeric uid/gid then accept it NFSv4.1: reject zero layout with zeroed stripe unit ...
nfs: switch NFS from ->get_sb() to ->mount() The last remaining instances of ->get_sb() can be converted ->mount() now - nothing in them uses new vfsmount anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
nfs: stop mangling ->mnt_devname on NFS now we can do that - nobody cares about its value anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>