diff options
Diffstat (limited to 'fs/nfsd/vfs.c')
| -rw-r--r-- | fs/nfsd/vfs.c | 134 |
1 files changed, 71 insertions, 63 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index a293f0273263..e3ef3ec0efd0 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1,7 +1,5 @@ #define MSNFS /* HACK HACK */ /* - * linux/fs/nfsd/vfs.c - * * File operations used by nfsd. Some of these have been ripped from * other parts of the kernel because they weren't exported, others * are partial duplicates with added or changed functionality. @@ -16,48 +14,31 @@ * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> */ -#include <linux/string.h> -#include <linux/time.h> -#include <linux/errno.h> #include <linux/fs.h> #include <linux/file.h> -#include <linux/mount.h> -#include <linux/major.h> #include <linux/splice.h> -#include <linux/proc_fs.h> -#include <linux/stat.h> #include <linux/fcntl.h> -#include <linux/net.h> -#include <linux/unistd.h> -#include <linux/slab.h> -#include <linux/pagemap.h> -#include <linux/in.h> -#include <linux/module.h> #include <linux/namei.h> -#include <linux/vfs.h> #include <linux/delay.h> -#include <linux/sunrpc/svc.h> -#include <linux/nfsd/nfsd.h> -#ifdef CONFIG_NFSD_V3 -#include <linux/nfs3.h> -#include <linux/nfsd/xdr3.h> -#endif /* CONFIG_NFSD_V3 */ -#include <linux/nfsd/nfsfh.h> #include <linux/quotaops.h> #include <linux/fsnotify.h> -#include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> #include <linux/xattr.h> +#include <linux/jhash.h> +#include <linux/ima.h> +#include <asm/uaccess.h> + +#ifdef CONFIG_NFSD_V3 +#include "xdr3.h" +#endif /* CONFIG_NFSD_V3 */ + #ifdef CONFIG_NFSD_V4 -#include <linux/nfs4.h> #include <linux/nfs4_acl.h> #include <linux/nfsd_idmap.h> -#include <linux/security.h> #endif /* CONFIG_NFSD_V4 */ -#include <linux/jhash.h> -#include <linux/ima.h> -#include <asm/uaccess.h> +#include "nfsd.h" +#include "vfs.h" #define NFSDDBG_FACILITY NFSDDBG_FILEOP @@ -89,12 +70,6 @@ struct raparm_hbucket { #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; -static inline int -nfsd_v4client(struct svc_rqst *rq) -{ - return rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4; -} - /* * Called from nfsd_lookup and encode_dirent. Check if we have crossed * a mount point. @@ -116,8 +91,16 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, exp2 = rqst_exp_get_by_name(rqstp, &path); if (IS_ERR(exp2)) { - if (PTR_ERR(exp2) != -ENOENT) - err = PTR_ERR(exp2); + err = PTR_ERR(exp2); + /* + * We normally allow NFS clients to continue + * "underneath" a mountpoint that is not exported. + * The exception is V4ROOT, where no traversal is ever + * allowed without an explicit export of the new + * directory. + */ + if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) + err = 0; path_put(&path); goto out; } @@ -141,6 +124,53 @@ out: return err; } +static void follow_to_parent(struct path *path) +{ + struct dentry *dp; + + while (path->dentry == path->mnt->mnt_root && follow_up(path)) + ; + dp = dget_parent(path->dentry); + dput(path->dentry); + path->dentry = dp; +} + +static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) +{ + struct svc_export *exp2; + struct path path = {.mnt = mntget((*exp)->ex_path.mnt), + .dentry = dget(dparent)}; + + follow_to_parent(&path); + + exp2 = rqst_exp_parent(rqstp, &path); + if (PTR_ERR(exp2) == -ENOENT) { + *dentryp = dget(dparent); + } else if (IS_ERR(exp2)) { + path_put(&path); + return PTR_ERR(exp2); + } else { + *dentryp = dget(path.dentry); + exp_put(*exp); + *exp = exp2; + } + path_put(&path); + return 0; +} + +/* + * For nfsd purposes, we treat V4ROOT exports as though there was an + * export at *every* directory. + */ +int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) +{ + if (d_mountpoint(dentry)) + return 1; + if (!(exp->ex_flags & NFSEXP_V4ROOT)) + return 0; + return dentry->d_inode != NULL; +} + __be32 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, unsigned int len, @@ -169,35 +199,13 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, dentry = dget(dparent); else if (dparent != exp->ex_path.dentry) dentry = dget_parent(dparent); - else if (!EX_NOHIDE(exp)) + else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) dentry = dget(dparent); /* .. == . just like at / */ else { /* checking mountpoint crossing is very different when stepping up */ - struct svc_export *exp2 = NULL; - struct dentry *dp; - struct path path = {.mnt = mntget(exp->ex_path.mnt), - .dentry = dget(dparent)}; - - while (path.dentry == path.mnt->mnt_root && - follow_up(&path)) - ; - dp = dget_parent(path.dentry); - dput(path.dentry); - path.dentry = dp; - - exp2 = rqst_exp_parent(rqstp, &path); - if (PTR_ERR(exp2) == -ENOENT) { - dentry = dget(dparent); - } else if (IS_ERR(exp2)) { - host_err = PTR_ERR(exp2); - path_put(&path); + host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); + if (host_err) goto out_nfserr; - } else { - dentry = dget(path.dentry); - exp_put(exp); - exp = exp2; - } - path_put(&path); } } else { fh_lock(fhp); @@ -208,7 +216,7 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, /* * check if we have crossed a mount point ... */ - if (d_mountpoint(dentry)) { + if (nfsd_mountpoint(dentry, exp)) { if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { dput(dentry); goto out_nfserr; |