From b1942c5f8cf3bea3a3c88a7498ae4c4361f31afe Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 16 Mar 2011 05:44:14 -0400 Subject: [PATCH] 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/dir.c | 13 +++++++++++++ fs/nfs/getroot.c | 36 ++++++++++++++++++++++++++++++++---- fs/nfs/unlink.c | 20 ++++++++++++++++++++ 3 files changed, 65 insertions(+), 4 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 2c3eb33b904d..abdf38d5971d 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1169,11 +1169,23 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) iput(inode); } +static void nfs_d_release(struct dentry *dentry) +{ + /* free cached devname value, if it survived that far */ + if (unlikely(dentry->d_fsdata)) { + if (dentry->d_flags & DCACHE_NFSFS_RENAMED) + WARN_ON(1); + else + kfree(dentry->d_fsdata); + } +} + const struct dentry_operations nfs_dentry_operations = { .d_revalidate = nfs_lookup_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, .d_automount = nfs_d_automount, + .d_release = nfs_d_release, }; static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) @@ -1248,6 +1260,7 @@ const struct dentry_operations nfs4_dentry_operations = { .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, .d_automount = nfs_d_automount, + .d_release = nfs_d_release, }; /* 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; diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index 6481d537d69d..8d6864c2a5fa 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -148,6 +148,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n alias = d_lookup(parent, &data->args.name); if (alias != NULL) { int ret = 0; + void *devname_garbage = NULL; /* * Hey, we raced with lookup... See if we need to transfer @@ -157,6 +158,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n spin_lock(&alias->d_lock); if (alias->d_inode != NULL && !(alias->d_flags & DCACHE_NFSFS_RENAMED)) { + devname_garbage = alias->d_fsdata; alias->d_fsdata = data; alias->d_flags |= DCACHE_NFSFS_RENAMED; ret = 1; @@ -164,6 +166,13 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n spin_unlock(&alias->d_lock); nfs_dec_sillycount(dir); dput(alias); + /* + * If we'd displaced old cached devname, free it. At that + * point dentry is definitely not a root, so we won't need + * that anymore. + */ + if (devname_garbage) + kfree(devname_garbage); return ret; } data->dir = igrab(dir); @@ -252,6 +261,7 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) { struct nfs_unlinkdata *data; int status = -ENOMEM; + void *devname_garbage = NULL; data = kzalloc(sizeof(*data), GFP_KERNEL); if (data == NULL) @@ -269,8 +279,16 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) if (dentry->d_flags & DCACHE_NFSFS_RENAMED) goto out_unlock; dentry->d_flags |= DCACHE_NFSFS_RENAMED; + devname_garbage = dentry->d_fsdata; dentry->d_fsdata = data; spin_unlock(&dentry->d_lock); + /* + * If we'd displaced old cached devname, free it. At that + * point dentry is definitely not a root, so we won't need + * that anymore. + */ + if (devname_garbage) + kfree(devname_garbage); return 0; out_unlock: spin_unlock(&dentry->d_lock); @@ -299,6 +317,7 @@ nfs_complete_unlink(struct dentry *dentry, struct inode *inode) if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; data = dentry->d_fsdata; + dentry->d_fsdata = NULL; } spin_unlock(&dentry->d_lock); @@ -315,6 +334,7 @@ nfs_cancel_async_unlink(struct dentry *dentry) struct nfs_unlinkdata *data = dentry->d_fsdata; dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; + dentry->d_fsdata = NULL; spin_unlock(&dentry->d_lock); nfs_free_unlinkdata(data); return; -- 2.20.1