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authorTrond Myklebust <Trond.Myklebust@netapp.com>2007-08-31 10:45:17 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-31 20:26:45 -0700
commite89a5a43b95cdc4305b7c8e8121a380f02476636 (patch)
treeba286205f1ad11119a06b77fb6671ce9aacac13a /fs
parent36ad4885c47c2187822f2783fb46fde2d36bf200 (diff)
downloadlinux-linaro-e89a5a43b95cdc4305b7c8e8121a380f02476636.tar.gz
NFS: Fix the mount regression
This avoids the recent NFS mount regression (returning EBUSY when mounting the same filesystem twice with different parameters). The best I can do given the constraints appears to be to have the kernel first look for a superblock that matches both the fsid and the user-specified mount options, and then spawn off a new superblock if that search fails. Note that this is not the same as specifying nosharecache everywhere since nosharecache will never attempt to match an existing superblock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Tested-by: Hua Zhong <hzhong@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfs/super.c110
1 files changed, 64 insertions, 46 deletions
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b2a851c1b8c..46139003ea0 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1303,34 +1303,6 @@ static void nfs_clone_super(struct super_block *sb,
nfs_initialise_sb(sb);
}
-static int nfs_set_super(struct super_block *s, void *_server)
-{
- struct nfs_server *server = _server;
- int ret;
-
- s->s_fs_info = server;
- ret = set_anon_super(s, server);
- if (ret == 0)
- server->s_dev = s->s_dev;
- return ret;
-}
-
-static int nfs_compare_super(struct super_block *sb, void *data)
-{
- struct nfs_server *server = data, *old = NFS_SB(sb);
-
- 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)
- return 0;
- if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
- return 0;
- 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)
@@ -1359,9 +1331,46 @@ static int nfs_compare_mount_options(const struct super_block *s, const struct n
goto Ebusy;
if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
goto Ebusy;
- return 0;
+ return 1;
Ebusy:
- return -EBUSY;
+ return 0;
+}
+
+struct nfs_sb_mountdata {
+ struct nfs_server *server;
+ int mntflags;
+};
+
+static int nfs_set_super(struct super_block *s, void *data)
+{
+ struct nfs_sb_mountdata *sb_mntdata = data;
+ struct nfs_server *server = sb_mntdata->server;
+ int ret;
+
+ s->s_flags = sb_mntdata->mntflags;
+ s->s_fs_info = server;
+ ret = set_anon_super(s, server);
+ if (ret == 0)
+ server->s_dev = s->s_dev;
+ return ret;
+}
+
+static int nfs_compare_super(struct super_block *sb, void *data)
+{
+ struct nfs_sb_mountdata *sb_mntdata = data;
+ struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
+ int mntflags = sb_mntdata->mntflags;
+
+ 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)
+ return 0;
+ if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
+ return 0;
+ return nfs_compare_mount_options(sb, server, mntflags);
}
static int nfs_get_sb(struct file_system_type *fs_type,
@@ -1373,6 +1382,9 @@ static int nfs_get_sb(struct file_system_type *fs_type,
struct nfs_mount_data *data = raw_data;
struct dentry *mntroot;
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+ struct nfs_sb_mountdata sb_mntdata = {
+ .mntflags = flags,
+ };
int error;
/* Validate the mount data */
@@ -1386,28 +1398,25 @@ static int nfs_get_sb(struct file_system_type *fs_type,
error = PTR_ERR(server);
goto out;
}
+ sb_mntdata.server = server;
if (server->flags & NFS_MOUNT_UNSHARED)
compare_super = NULL;
/* Get a superblock - note that we may end up sharing one that already exists */
- s = sget(fs_type, compare_super, nfs_set_super, server);
+ s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_err_nosb;
}
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) {
/* initial superblock/root creation */
- s->s_flags = flags;
nfs_fill_super(s, data);
}
@@ -1460,6 +1469,9 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
struct nfs_server *server;
struct dentry *mntroot;
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+ struct nfs_sb_mountdata sb_mntdata = {
+ .mntflags = flags,
+ };
int error;
dprintk("--> nfs_xdev_get_sb()\n");
@@ -1470,28 +1482,25 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(server);
goto out_err_noserver;
}
+ sb_mntdata.server = server;
if (server->flags & NFS_MOUNT_UNSHARED)
compare_super = NULL;
/* Get a superblock - note that we may end up sharing one that already exists */
- s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
+ s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_err_nosb;
}
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) {
/* initial superblock/root creation */
- s->s_flags = flags;
nfs_clone_super(s, data->sb);
}
@@ -1729,6 +1738,9 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
struct dentry *mntroot;
char *mntpath = NULL, *hostname = NULL, *ip_addr = NULL;
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+ struct nfs_sb_mountdata sb_mntdata = {
+ .mntflags = flags,
+ };
int error;
/* Validate the mount data */
@@ -1744,12 +1756,13 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
error = PTR_ERR(server);
goto out;
}
+ sb_mntdata.server = server;
if (server->flags & NFS4_MOUNT_UNSHARED)
compare_super = NULL;
/* Get a superblock - note that we may end up sharing one that already exists */
- s = sget(fs_type, compare_super, nfs_set_super, server);
+ s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_free;
@@ -1762,7 +1775,6 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
if (!s->s_root) {
/* initial superblock/root creation */
- s->s_flags = flags;
nfs4_fill_super(s);
}
@@ -1816,6 +1828,9 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
struct nfs_server *server;
struct dentry *mntroot;
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+ struct nfs_sb_mountdata sb_mntdata = {
+ .mntflags = flags,
+ };
int error;
dprintk("--> nfs4_xdev_get_sb()\n");
@@ -1826,12 +1841,13 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(server);
goto out_err_noserver;
}
+ sb_mntdata.server = server;
if (server->flags & NFS4_MOUNT_UNSHARED)
compare_super = NULL;
/* Get a superblock - note that we may end up sharing one that already exists */
- s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
+ s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_err_nosb;
@@ -1844,7 +1860,6 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
if (!s->s_root) {
/* initial superblock/root creation */
- s->s_flags = flags;
nfs4_clone_super(s, data->sb);
}
@@ -1887,6 +1902,9 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
struct dentry *mntroot;
struct nfs_fh mntfh;
int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
+ struct nfs_sb_mountdata sb_mntdata = {
+ .mntflags = flags,
+ };
int error;
dprintk("--> nfs4_referral_get_sb()\n");
@@ -1897,12 +1915,13 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
error = PTR_ERR(server);
goto out_err_noserver;
}
+ sb_mntdata.server = server;
if (server->flags & NFS4_MOUNT_UNSHARED)
compare_super = NULL;
/* Get a superblock - note that we may end up sharing one that already exists */
- s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
+ s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
if (IS_ERR(s)) {
error = PTR_ERR(s);
goto out_err_nosb;
@@ -1915,7 +1934,6 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
if (!s->s_root) {
/* initial superblock/root creation */
- s->s_flags = flags;
nfs4_fill_super(s);
}