From 0d5839ad05acd0fe2a84a39f33ac5efdf634a5a5 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 16 Mar 2011 05:27:27 -0400 Subject: nfs: propagate devname to nfs{,4}_get_root() step 1 of ->mnt_devname fixes: make sure we have the value of devname available in ..._get_root(). Signed-off-by: Al Viro --- fs/nfs/getroot.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b5ffe8fa291f..4d6e5a317e6d 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -75,7 +75,8 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i /* * get an NFS2/NFS3 root dentry from the root filehandle */ -struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh) +struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, + const char *devname) { struct nfs_server *server = NFS_SB(sb); struct nfs_fsinfo fsinfo; @@ -169,7 +170,8 @@ out: /* * get an NFS4 root dentry from the root filehandle */ -struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) +struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh, + const char *devname) { struct nfs_server *server = NFS_SB(sb); struct nfs_fattr *fattr = NULL; -- cgit From b1942c5f8cf3bea3a3c88a7498ae4c4361f31afe Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 16 Mar 2011 05:44:14 -0400 Subject: nfs: store devname at disconnected NFS roots part 2: make sure that disconnected roots have corresponding mnt_devname values stashed into them. Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the found root, provided that it is disconnected. Have ->d_release() free it when dentry goes away. Have the places where NFS uses ->d_fsdata for sillyrename (and that can *never* happen to a disconnected root - dentry will be attached to its parent) free old devname copies if they find those. Signed-off-by: Al Viro --- fs/nfs/getroot.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index 4d6e5a317e6d..1084792bc0fe 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -82,12 +82,18 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, struct nfs_fsinfo fsinfo; struct dentry *ret; struct inode *inode; + void *name = kstrdup(devname, GFP_KERNEL); int error; + if (!name) + return ERR_PTR(-ENOMEM); + /* get the actual root for this mount */ fsinfo.fattr = nfs_alloc_fattr(); - if (fsinfo.fattr == NULL) + if (fsinfo.fattr == NULL) { + kfree(name); return ERR_PTR(-ENOMEM); + } error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo); if (error < 0) { @@ -120,7 +126,15 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, } security_d_instantiate(ret, inode); + spin_lock(&ret->d_lock); + if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) { + ret->d_fsdata = name; + name = NULL; + } + spin_unlock(&ret->d_lock); out: + if (name) + kfree(name); nfs_free_fattr(fsinfo.fattr); return ret; } @@ -177,21 +191,28 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh, struct nfs_fattr *fattr = NULL; struct dentry *ret; struct inode *inode; + void *name = kstrdup(devname, GFP_KERNEL); int error; dprintk("--> nfs4_get_root()\n"); + if (!name) + return ERR_PTR(-ENOMEM); + /* get the info about the server and filesystem */ error = nfs4_server_capabilities(server, mntfh); if (error < 0) { dprintk("nfs_get_root: getcaps error = %d\n", -error); + kfree(name); return ERR_PTR(error); } fattr = nfs_alloc_fattr(); - if (fattr == NULL) - return ERR_PTR(-ENOMEM);; + if (fattr == NULL) { + kfree(name); + return ERR_PTR(-ENOMEM); + } /* get the actual root for this mount */ error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr); @@ -225,8 +246,15 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh, } security_d_instantiate(ret, inode); - + spin_lock(&ret->d_lock); + if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) { + ret->d_fsdata = name; + name = NULL; + } + spin_unlock(&ret->d_lock); out: + if (name) + kfree(name); nfs_free_fattr(fattr); dprintk("<-- nfs4_get_root()\n"); return ret; -- cgit From 4667058b772857069378aa8f417203156e315e82 Mon Sep 17 00:00:00 2001 From: Gusev Vitaliy Date: Wed, 23 Mar 2011 00:40:25 +0300 Subject: nfs4: Fix NULL dereference at d_alloc_and_lookup() d_alloc_and_lookup() calls i_op->lookup method due to rootfh changes his fsid. During mount i_op of NFS root inode is set to nfs_mountpoint_inode_operations, if rpc_ops->getroot() and rpc_ops->getattr() return different fsid. After that nfs_follow_remote_path() raised oops: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) stack trace: d_alloc_and_lookup+0x4c/0x74 do_lookup+0x1e3/0x280 link_path_walk+0x12e/0xab0 nfs4_remote_get_sb+0x56/0x2c0 [nfs] path_walk+0x67/0xe0 vfs_path_lookup+0x8e/0x100 nfs_follow_remote_path+0x16f/0x3e0 [nfs] nfs4_try_mount+0x6f/0xd0 [nfs] nfs_get_sb+0x269/0x400 [nfs] vfs_kern_mount+0x8a/0x1f0 do_kern_mount+0x52/0x130 do_mount+0x20a/0x260 sys_mount+0x90/0xe0 system_call_fastpath+0x16/0x1b So just refresh fsid, as RFC3530 doesn't specify behavior in case of rootfh changes fsid. Signed-off-by: Vitaliy Gusev Signed-off-by: Trond Myklebust --- fs/nfs/getroot.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b5ffe8fa291f..79796521cfdc 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -199,6 +199,10 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) goto out; } + if (fattr->valid & NFS_ATTR_FATTR_FSID && + !nfs_fsid_equal(&server->fsid, &fattr->fsid)) + memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid)); + inode = nfs_fhget(sb, mntfh, fattr); if (IS_ERR(inode)) { dprintk("nfs_get_root: get root inode failed\n"); -- cgit