Attachment 186571 Details for Bug 243913 – nosharecache is on by default

nosharecache is on by default

linux-2.6.18-nfs-nosharecache-is-default.patch (text/x-patch), 9.76 KB, created by Steve Dickson on 2007-09-04 20:08:20 UTC

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Creator: Steve Dickson

Created: 2007-09-04 20:08:20 UTC

Size: 9.76 KB

patch

obsolete

>commit e89a5a43b95cdc4305b7c8e8121a380f02476636
>Author: Trond Myklebust <Trond.Myklebust@netapp.com>
>Date:   Fri Aug 31 10:45:17 2007 -0400
>
>    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>
>
>--- linux-2.6.18.i686/fs/nfs/super.c.orig	2007-08-28 09:09:19.716183000 -0400
>+++ linux-2.6.18.i686/fs/nfs/super.c	2007-09-04 15:13:32.030095000 -0400
>@@ -599,11 +599,52 @@ static void nfs_clone_super(struct super
>  	nfs_initialise_sb(sb);
> }
> 
>-static int nfs_set_super(struct super_block *s, void *_server)
>+#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)
> {
>-	struct nfs_server *server = _server;
>+	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 1;
>+Ebusy:
>+	return 0;
>+}
>+
>+struct nfs_sb_mountdata {
>+	struct nfs_server *server;
>+	int mntflags;
>+	int err_on_noshare;
>+};
>+
>+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)
>@@ -613,41 +654,29 @@ static int nfs_set_super(struct super_bl
> 
> static int nfs_compare_super(struct super_block *sb, void *data)
> {
>-	struct nfs_server *server = data, *old = NFS_SB(sb);
>+	struct nfs_sb_mountdata *sb_mntdata = data;
>+	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
>+	int mntflags = sb_mntdata->mntflags;
>+	int cc, fsc = (server->flags & NFS_MOUNT_FSCACHE);
> 
> 	if (memcmp(&old->nfs_client->cl_addr,
> 				&server->nfs_client->cl_addr,
> 				sizeof(old->nfs_client->cl_addr)) != 0)
> 		return 0;
>+	/* Wit FS-Cache sharing is a must with the same server */
>+	if (fsc)
>+		sb_mntdata->err_on_noshare = 1;
> 	/* 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;
>-}
>+	cc =  nfs_compare_mount_options(sb, server, mntflags);
> 
>-static int nfs_compare_mount_options(const struct nfs_server *a, const struct nfs_server *b)
>-{
>-	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;
>-	return 0;
>-Ebusy:
>-	return -EBUSY;
>+	if (fsc && cc)
>+		sb_mntdata->err_on_noshare = 0;
>+
>+	return cc;
> }
> 
> static int nfs_get_sb(struct file_system_type *fs_type,
>@@ -659,6 +688,10 @@ static int nfs_get_sb(struct file_system
> 	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,
>+		.err_on_noshare = 0,
>+	};
> 	int error;
> 
> 	/* Validate the mount data */
>@@ -672,27 +705,24 @@ static int nfs_get_sb(struct file_system
> 		error = PTR_ERR(server);
> 		goto out_err_noserver;
> 	}
>+	sb_mntdata.server = server;
> 
>-	if (server->flags & NFS_MOUNT_UNSHARED) {
>-		if (server->flags & NFS_MOUNT_FSCACHE) {
>-			error = -EINVAL;
>-			goto out_err_nosb;
>-		}
>+	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(server, NFS_SB(s));
> 		nfs_free_server(server);
> 		server = NULL;
>-		if (error < 0)
>-			goto error_splat_super;
>+	} else if ((server->flags & NFS_MOUNT_FSCACHE) 
>+			&& sb_mntdata.err_on_noshare) {
>+		error = -EINVAL;
>+		goto error_splat_super;
> 	}
> 
> 	if (!s->s_root) {
>@@ -746,6 +776,10 @@ static int nfs_xdev_get_sb(struct file_s
> 	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,
>+		.err_on_noshare = 0,
>+	};
> 	int error;
> 
> 	dprintk("--> nfs_xdev_get_sb()\n");
>@@ -756,16 +790,13 @@ static int nfs_xdev_get_sb(struct file_s
> 		error = PTR_ERR(server);
> 		goto out_err_noserver;
> 	}
>+	sb_mntdata.server = server;
> 
>-	if (server->flags & NFS_MOUNT_UNSHARED) {
>-		if (server->flags & NFS_MOUNT_FSCACHE) {
>-			error = -EINVAL;
>-			goto out_err_nosb;
>-		}
>+	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;
>@@ -774,6 +805,10 @@ static int nfs_xdev_get_sb(struct file_s
> 	if (s->s_fs_info != server) {
> 		nfs_free_server(server);
> 		server = NULL;
>+	} else if ((server->flags & NFS_MOUNT_FSCACHE) 
>+			&& sb_mntdata.err_on_noshare) {
>+		error = -EINVAL;
>+		goto error_splat_super;
> 	}
> 
> 	if (!s->s_root) {
>@@ -871,6 +906,10 @@ static int nfs4_get_sb(struct file_syste
> 	char *mntpath = NULL, *hostname = NULL, ip_addr[16];
> 	void *p;
> 	int (*compare_super)(struct super_block *,void *) = nfs_compare_super;
>+	struct nfs_sb_mountdata sb_mntdata = {
>+		.mntflags = flags,
>+		.err_on_noshare = 0,
>+	};
> 	int error;
> 
> 	if (data == NULL) {
>@@ -938,27 +977,25 @@ static int nfs4_get_sb(struct file_syste
> 		error = PTR_ERR(server);
> 		goto out_err_noserver;
> 	}
>+	sb_mntdata.server = server;
> 
>-	if (server->flags & NFS_MOUNT_UNSHARED) {
>-		if (server->flags & NFS_MOUNT_FSCACHE) {
>-			error = -EINVAL;
>-			goto out_free;
>-		}
>+	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_free;
> 	}
> 
> 	if (s->s_fs_info != server) {
>-		error = nfs_compare_mount_options(server, NFS_SB(s));
> 		nfs_free_server(server);
> 		server = NULL;
>-		if (error < 0)
>-			goto error_splat_super;
>+	} else if ((server->flags & NFS_MOUNT_FSCACHE) 
>+			&& sb_mntdata.err_on_noshare) {
>+		error = -EINVAL;
>+		goto error_splat_super;
> 	}
> 
> 	if (!s->s_root) {
>@@ -1020,6 +1057,9 @@ static int nfs4_xdev_get_sb(struct file_
> 	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");
>@@ -1030,6 +1070,7 @@ static int nfs4_xdev_get_sb(struct file_
> 		error = PTR_ERR(server);
> 		goto out_err_noserver;
> 	}
>+	sb_mntdata.server = server;
> 
> 	if (server->flags & NFS4_MOUNT_UNSHARED) {
> 		if (server->flags & NFS4_MOUNT_FSCACHE) {
>@@ -1039,7 +1080,7 @@ static int nfs4_xdev_get_sb(struct file_
> 		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;
>@@ -1095,6 +1136,9 @@ static int nfs4_referral_get_sb(struct f
> 	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");
>@@ -1105,6 +1149,7 @@ static int nfs4_referral_get_sb(struct f
> 		error = PTR_ERR(server);
> 		goto out_err_noserver;
> 	}
>+	sb_mntdata.server = server;
> 
> 	if (server->flags & NFS4_MOUNT_UNSHARED) {
> 		if (server->flags & NFS4_MOUNT_FSCACHE) {
>@@ -1114,7 +1159,7 @@ static int nfs4_referral_get_sb(struct f
> 		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;
>@@ -1127,7 +1172,6 @@ static int nfs4_referral_get_sb(struct f
> 
> 	if (!s->s_root) {
> 		/* initial superblock/root creation */
>-		s->s_flags = flags;
> 		nfs4_fill_super(s);
> 	}
>

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Attachments on bug 243913: 156814 | 186571