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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-05-16 16:53:28 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-07-10 23:40:48 -0400 |
| commit | 275a5d24bf56b2d9dd4644c54a56366b89a028f1 (patch) | |
| tree | 2c429fc9480ef292b8cfdc81be05f3ff2b2c02a5 /fs/nfs/super.c | |
| parent | 75180df2ed467866ada839fe73cf7cc7d75c0a22 (diff) | |
| download | lwn-275a5d24bf56b2d9dd4644c54a56366b89a028f1.tar.gz lwn-275a5d24bf56b2d9dd4644c54a56366b89a028f1.zip | |
NFS: Error when mounting the same filesystem with different options
Unless the user sets the NFS_MOUNT_NOSHAREDCACHE mount flag, we should
return EBUSY if the filesystem is already mounted on a superblock that
has set conflicting mount options.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/super.c')
| -rw-r--r-- | fs/nfs/super.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 1b555cd41e3b..a2b1af89ca1a 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1317,7 +1317,9 @@ static int nfs_compare_super(struct super_block *sb, void *data) { struct nfs_server *server = data, *old = NFS_SB(sb); - if (old->nfs_client != server->nfs_client) + if (memcmp(&old->nfs_client->cl_addr, + &server->nfs_client->cl_addr, + sizeof(old->nfs_client->cl_addr)) != 0) return 0; /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */ if (old->flags & NFS_MOUNT_UNSHARED) @@ -1327,6 +1329,39 @@ static int nfs_compare_super(struct super_block *sb, void *data) return 1; } +#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS) + +static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags) +{ + const struct nfs_server *a = s->s_fs_info; + const struct rpc_clnt *clnt_a = a->client; + const struct rpc_clnt *clnt_b = b->client; + + if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK)) + goto Ebusy; + if (a->nfs_client != b->nfs_client) + goto Ebusy; + if (a->flags != b->flags) + goto Ebusy; + if (a->wsize != b->wsize) + goto Ebusy; + if (a->rsize != b->rsize) + goto Ebusy; + if (a->acregmin != b->acregmin) + goto Ebusy; + if (a->acregmax != b->acregmax) + goto Ebusy; + if (a->acdirmin != b->acdirmin) + goto Ebusy; + if (a->acdirmax != b->acdirmax) + goto Ebusy; + if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor) + goto Ebusy; + return 0; +Ebusy: + return -EBUSY; +} + static int nfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt) { @@ -1361,8 +1396,11 @@ static int nfs_get_sb(struct file_system_type *fs_type, } if (s->s_fs_info != server) { + error = nfs_compare_mount_options(s, server, flags); nfs_free_server(server); server = NULL; + if (error < 0) + goto error_splat_super; } if (!s->s_root) { @@ -1442,8 +1480,11 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags, } if (s->s_fs_info != server) { + error = nfs_compare_mount_options(s, server, flags); nfs_free_server(server); server = NULL; + if (error < 0) + goto error_splat_super; } if (!s->s_root) { |