diff options
| -rw-r--r-- | fs/namei.c | 21 | ||||
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 8 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 6 | ||||
| -rw-r--r-- | fs/stat.c | 8 | ||||
| -rw-r--r-- | fs/xfs/xfs_ioctl.c | 4 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
6 files changed, 35 insertions, 13 deletions
diff --git a/fs/namei.c b/fs/namei.c index 5b4eed221530..12a4159de72a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4669,6 +4669,27 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) EXPORT_SYMBOL(generic_readlink); /** + * vfs_readlink - copy symlink body into userspace buffer + * @dentry: dentry on which to get symbolic link + * @buffer: user memory pointer + * @buflen: size of buffer + * + * Does not touch atime. That's up to the caller if necessary + * + * Does not call security hook. + */ +int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen) +{ + struct inode *inode = d_inode(dentry); + + if (!inode->i_op->readlink) + return -EINVAL; + + return inode->i_op->readlink(dentry, buffer, buflen); +} +EXPORT_SYMBOL(vfs_readlink); + +/** * vfs_get_link - get symlink body * @dentry: dentry on which to get symbolic link * @done: caller needs to free returned data with this diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index c2d2895a1ec1..645e1e3c3110 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3576,10 +3576,10 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd if (!p) return nfserr_resource; /* - * XXX: By default, the ->readlink() VFS op will truncate symlinks - * if they would overflow the buffer. Is this kosher in NFSv4? If - * not, one easy fix is: if ->readlink() precisely fills the buffer, - * assume that truncation occurred, and return NFS4ERR_RESOURCE. + * XXX: By default, vfs_readlink() will truncate symlinks if they + * would overflow the buffer. Is this kosher in NFSv4? If not, one + * easy fix is: if vfs_readlink() precisely fills the buffer, assume + * that truncation occurred, and return NFS4ERR_RESOURCE. */ nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, (char *)p, &maxcount); diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 8ca642fe9b21..b854f02c1c36 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1451,7 +1451,6 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, __be32 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) { - struct inode *inode; mm_segment_t oldfs; __be32 err; int host_err; @@ -1463,10 +1462,9 @@ nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) path.mnt = fhp->fh_export->ex_path.mnt; path.dentry = fhp->fh_dentry; - inode = d_inode(path.dentry); err = nfserr_inval; - if (!inode->i_op->readlink) + if (!d_is_symlink(path.dentry)) goto out; touch_atime(&path); @@ -1475,7 +1473,7 @@ nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) */ oldfs = get_fs(); set_fs(KERNEL_DS); - host_err = inode->i_op->readlink(path.dentry, (char __user *)buf, *lenp); + host_err = vfs_readlink(path.dentry, (char __user *)buf, *lenp); set_fs(oldfs); if (host_err < 0) diff --git a/fs/stat.c b/fs/stat.c index bc045c7994e1..0b210c3ead5c 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -329,12 +329,14 @@ retry: struct inode *inode = d_backing_inode(path.dentry); error = empty ? -ENOENT : -EINVAL; - if (inode->i_op->readlink) { + /* + * AFS mountpoints allow readlink(2) but are not symlinks + */ + if (d_is_symlink(path.dentry) || inode->i_op->readlink) { error = security_inode_readlink(path.dentry); if (!error) { touch_atime(&path); - error = inode->i_op->readlink(path.dentry, - buf, bufsiz); + error = vfs_readlink(path.dentry, buf, bufsiz); } } path_put(&path); diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index c245bed3249b..9b12f7c993e9 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -287,7 +287,7 @@ xfs_readlink_by_handle( return PTR_ERR(dentry); /* Restrict this handle operation to symlinks only. */ - if (!d_inode(dentry)->i_op->readlink) { + if (!d_is_symlink(dentry)) { error = -EINVAL; goto out_dput; } @@ -297,7 +297,7 @@ xfs_readlink_by_handle( goto out_dput; } - error = d_inode(dentry)->i_op->readlink(dentry, hreq->ohandle, olen); + error = vfs_readlink(dentry, hreq->ohandle, olen); out_dput: dput(dentry); diff --git a/include/linux/fs.h b/include/linux/fs.h index dc0478c07b2a..eba20d1c068d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2935,6 +2935,7 @@ extern int vfs_lstat(const char __user *, struct kstat *); extern int vfs_fstat(unsigned int, struct kstat *); extern int vfs_fstatat(int , const char __user *, struct kstat *, int); extern const char *vfs_get_link(struct dentry *, struct delayed_call *); +extern int vfs_readlink(struct dentry *, char __user *, int); extern int __generic_block_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |