Attachment 158984 Details for Bug 207670 – Proposed Upstream patch.

[patch] Proposed Upstream patch.

linux-2.6.22-nfs-nosharecache-mounts.patch (text/plain), 6.57 KB, created by Steve Dickson on 2007-07-11 18:12:08 UTC

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Creator: Steve Dickson

Created: 2007-07-11 18:12:08 UTC

Size: 6.57 KB

patch

obsolete

>commit 0e1675c09fe57d41c4b8e60182cb924e8736ff41
>Author: Trond Myklebust <Trond.Myklebust@netapp.com>
>Date:   Wed May 16 16:53:28 2007 -0400
>
>    NFS: Add the mount option "nosharecache"
>    
>    Prior to David Howell's mount changes in 2.6.18, users who mounted
>    different directories which happened to be from the same filesystem on the
>    server would get different super blocks, and hence could choose different
>    mount options. As long as there were no hard linked files that crossed from
>    one subtree to another, this was quite safe.
>    Post the changes, if the two directories are on the same filesystem (have
>    the same 'fsid'), they will share the same super block, and hence the same
>    mount options.
>    
>    Add a flag to allow users to elect not to share the NFS super block with
>    another mount point, even if the fsids are the same. This will allow
>    users to set different mount options for the two different super blocks, as
>    was previously possible. It is still up to the user to ensure that there
>    are no cache coherency issues when doing this, however the default
>    behaviour will be to share super blocks whenever two paths result in
>    the same fsid.
>    
>    Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
>
>diff --git a/fs/nfs/super.c b/fs/nfs/super.c
>index ca20d3c..c03120a 100644
>--- a/fs/nfs/super.c
>+++ b/fs/nfs/super.c
>@@ -291,6 +291,7 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
> 		{ NFS_MOUNT_NONLM, ",nolock", "" },
> 		{ NFS_MOUNT_NOACL, ",noacl", "" },
> 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
>+		{ NFS_MOUNT_UNSHARED, ",nosharecache", ""},
> 		{ 0, NULL, NULL }
> 	};
> 	const struct proc_nfs_info *nfs_infop;
>@@ -602,6 +603,9 @@ static int nfs_compare_super(struct super_block *sb, void *data)
> 
> 	if (old->nfs_client != server->nfs_client)
> 		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;
>@@ -615,6 +619,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
> 	struct nfs_fh mntfh;
> 	struct nfs_mount_data *data = raw_data;
> 	struct dentry *mntroot;
>+	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
> 	int error;
> 
> 	/* Validate the mount data */
>@@ -629,8 +634,11 @@ static int nfs_get_sb(struct file_system_type *fs_type,
> 		goto out_err_noserver;
> 	}
> 
>+	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, nfs_compare_super, nfs_set_super, server);
>+	s = sget(fs_type, compare_super, nfs_set_super, server);
> 	if (IS_ERR(s)) {
> 		error = PTR_ERR(s);
> 		goto out_err_nosb;
>@@ -691,6 +699,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
> 	struct super_block *s;
> 	struct nfs_server *server;
> 	struct dentry *mntroot;
>+	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
> 	int error;
> 
> 	dprintk("--> nfs_xdev_get_sb()\n");
>@@ -702,8 +711,11 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
> 		goto out_err_noserver;
> 	}
> 
>+	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, nfs_compare_super, nfs_set_super, server);
>+	s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
> 	if (IS_ERR(s)) {
> 		error = PTR_ERR(s);
> 		goto out_err_nosb;
>@@ -808,6 +820,7 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
> 	struct dentry *mntroot;
> 	char *mntpath = NULL, *hostname = NULL, ip_addr[16];
> 	void *p;
>+	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
> 	int error;
> 
> 	if (data == NULL) {
>@@ -879,8 +892,11 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
> 		goto out_err_noserver;
> 	}
> 
>+	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, nfs_compare_super, nfs_set_super, server);
>+	s = sget(fs_type, compare_super, nfs_set_super, server);
> 	if (IS_ERR(s)) {
> 		error = PTR_ERR(s);
> 		goto out_free;
>@@ -949,6 +965,7 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
> 	struct super_block *s;
> 	struct nfs_server *server;
> 	struct dentry *mntroot;
>+	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
> 	int error;
> 
> 	dprintk("--> nfs4_xdev_get_sb()\n");
>@@ -960,8 +977,11 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
> 		goto out_err_noserver;
> 	}
> 
>+	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, nfs_compare_super, nfs_set_super, server);
>+	s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
> 	if (IS_ERR(s)) {
> 		error = PTR_ERR(s);
> 		goto out_err_nosb;
>@@ -1016,6 +1036,7 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
> 	struct nfs_server *server;
> 	struct dentry *mntroot;
> 	struct nfs_fh mntfh;
>+	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
> 	int error;
> 
> 	dprintk("--> nfs4_referral_get_sb()\n");
>@@ -1027,8 +1048,11 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
> 		goto out_err_noserver;
> 	}
> 
>+	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, nfs_compare_super, nfs_set_super, server);
>+	s = sget(&nfs_fs_type, compare_super, nfs_set_super, server);
> 	if (IS_ERR(s)) {
> 		error = PTR_ERR(s);
> 		goto out_err_nosb;
>diff --git a/include/linux/nfs4_mount.h b/include/linux/nfs4_mount.h
>index 26b4c83..ad1bd4a 100644
>--- a/include/linux/nfs4_mount.h
>+++ b/include/linux/nfs4_mount.h
>@@ -65,6 +65,7 @@ struct nfs4_mount_data {
> #define NFS4_MOUNT_NOCTO	0x0010	/* 1 */
> #define NFS4_MOUNT_NOAC		0x0020	/* 1 */
> #define NFS4_MOUNT_STRICTLOCK	0x1000	/* 1 */
>+#define NFS4_MOUNT_UNSHARED	0x8000	/* 1 */
> #define NFS4_MOUNT_FLAGMASK	0xFFFF
> 
> #endif
>diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h
>index cc8b9c5..3e3b521 100644
>--- a/include/linux/nfs_mount.h
>+++ b/include/linux/nfs_mount.h
>@@ -62,6 +62,7 @@ struct nfs_mount_data {
> #define NFS_MOUNT_STRICTLOCK	0x1000	/* reserved for NFSv4 */
> #define NFS_MOUNT_SECFLAVOUR	0x2000	/* 5 */
> #define NFS_MOUNT_NORDIRPLUS	0x4000	/* 5 */
>+#define NFS_MOUNT_UNSHARED	0x8000	/* 5 */
> #define NFS_MOUNT_FLAGMASK	0xFFFF
> 
> #endif

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