From: Christoph Hellwig Subject: [PATCH 2/2] add a file_permission helper Date: Tue, 1 Nov 2005 03:03:17 +0100 Message-ID: <20051101020317.GB23020@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org Return-path: Received: from verein.lst.de ([213.95.11.210]:43945 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S964929AbVKACDX (ORCPT ); Mon, 31 Oct 2005 21:03:23 -0500 To: akpm@osdl.org Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org A few more callers of permission() just want to check for a different access pattern on an already open file. This patch adds a wrapper for permission() that takes a file in preparation of per-mount read-only support and to clean up the callers a little. The helper is not intended for new code, everything without the interface set in stone should use vfs_permission() Signed-off-by: Christoph Hellwig Index: linux-2.6/drivers/block/floppy.c =================================================================== --- linux-2.6.orig/drivers/block/floppy.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/drivers/block/floppy.c 2005-10-31 17:55:19.000000000 +0100 @@ -3770,8 +3770,7 @@ /* Allow ioctls if we have write-permissions even if read-only open. * Needed so that programs such as fdrawcmd still can work on write * protected disks */ - if (filp->f_mode & 2 - || permission(filp->f_dentry->d_inode, 2, NULL) == 0) + if ((filp->f_mode & FMODE_WRITE) || !file_permission(filp, MAY_WRITE)) filp->private_data = (void *)8; if (UFDCS->rawcmd == 1) Index: linux-2.6/fs/binfmt_misc.c =================================================================== --- linux-2.6.orig/fs/binfmt_misc.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/fs/binfmt_misc.c 2005-10-31 17:55:19.000000000 +0100 @@ -150,7 +150,7 @@ /* if the binary is not readable than enforce mm->dumpable=0 regardless of the interpreter's permissions */ - if (permission(bprm->file->f_dentry->d_inode, MAY_READ, NULL)) + if (file_permission(bprm->file, MAY_READ)) bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; allow_write_access(bprm->file); Index: linux-2.6/fs/exec.c =================================================================== --- linux-2.6.orig/fs/exec.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/fs/exec.c 2005-10-31 17:55:19.000000000 +0100 @@ -891,7 +891,7 @@ flush_thread(); if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || - permission(bprm->file->f_dentry->d_inode,MAY_READ, NULL) || + file_permission(bprm->file, MAY_READ) || (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { suid_keys(current); current->mm->dumpable = suid_dumpable; Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/include/linux/fs.h 2005-10-31 17:55:19.000000000 +0100 @@ -878,6 +878,11 @@ extern void dentry_unhash(struct dentry *dentry); /* + * VFS file helper functions. + */ +extern int file_permission(struct file *, int); + +/* * File types * * NOTE! These match bits 12..15 of stat.st_mode Index: linux-2.6/fs/ncpfs/ioctl.c =================================================================== --- linux-2.6.orig/fs/ncpfs/ioctl.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/fs/ncpfs/ioctl.c 2005-10-31 17:55:23.000000000 +0100 @@ -30,11 +30,13 @@ #define NCP_PACKET_SIZE_INTERNAL 65536 static int -ncp_get_fs_info(struct ncp_server* server, struct inode* inode, struct ncp_fs_info __user *arg) +ncp_get_fs_info(struct ncp_server * server, struct file *file, + struct ncp_fs_info __user *arg) { + struct inode *inode = file->f_dentry->d_inode; struct ncp_fs_info info; - if ((permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(file, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; } @@ -58,11 +60,13 @@ } static int -ncp_get_fs_info_v2(struct ncp_server* server, struct inode* inode, struct ncp_fs_info_v2 __user * arg) +ncp_get_fs_info_v2(struct ncp_server * server, struct file *file, + struct ncp_fs_info_v2 __user * arg) { + struct inode *inode = file->f_dentry->d_inode; struct ncp_fs_info_v2 info2; - if ((permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(file, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; } @@ -190,7 +194,7 @@ switch (cmd) { case NCP_IOC_NCPREQUEST: - if ((permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(filp, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; } @@ -245,16 +249,16 @@ return ncp_conn_logged_in(inode->i_sb); case NCP_IOC_GET_FS_INFO: - return ncp_get_fs_info(server, inode, argp); + return ncp_get_fs_info(server, filp, argp); case NCP_IOC_GET_FS_INFO_V2: - return ncp_get_fs_info_v2(server, inode, argp); + return ncp_get_fs_info_v2(server, filp, argp); case NCP_IOC_GETMOUNTUID2: { unsigned long tmp = server->m.mounted_uid; - if ( (permission(inode, MAY_READ, NULL) != 0) + if ((file_permission(filp, MAY_READ) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -268,7 +272,7 @@ { struct ncp_setroot_ioctl sr; - if ( (permission(inode, MAY_READ, NULL) != 0) + if ((file_permission(filp, MAY_READ) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -343,7 +347,7 @@ #ifdef CONFIG_NCPFS_PACKET_SIGNING case NCP_IOC_SIGN_INIT: - if ((permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(filp, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -366,7 +370,7 @@ return 0; case NCP_IOC_SIGN_WANTED: - if ( (permission(inode, MAY_READ, NULL) != 0) + if ((file_permission(filp, MAY_READ) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -379,7 +383,7 @@ { int newstate; - if ( (permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(filp, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -400,7 +404,7 @@ #ifdef CONFIG_NCPFS_IOCTL_LOCKING case NCP_IOC_LOCKUNLOCK: - if ( (permission(inode, MAY_WRITE, NULL) != 0) + if ((file_permission(filp, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; @@ -605,7 +609,7 @@ #endif /* CONFIG_NCPFS_NLS */ case NCP_IOC_SETDENTRYTTL: - if ((permission(inode, MAY_WRITE, NULL) != 0) && + if ((file_permission(filp, MAY_WRITE) != 0) && (current->uid != server->m.mounted_uid)) return -EACCES; { @@ -635,7 +639,7 @@ so we have this out of switch */ if (cmd == NCP_IOC_GETMOUNTUID) { __kernel_uid_t uid = 0; - if ((permission(inode, MAY_READ, NULL) != 0) + if ((file_permission(filp, MAY_READ) != 0) && (current->uid != server->m.mounted_uid)) { return -EACCES; } Index: linux-2.6/fs/open.c =================================================================== --- linux-2.6.orig/fs/open.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/fs/open.c 2005-10-31 17:55:19.000000000 +0100 @@ -559,7 +559,7 @@ if (!S_ISDIR(inode->i_mode)) goto out_putf; - error = permission(inode, MAY_EXEC, NULL); + error = file_permission(file, MAY_EXEC); if (!error) set_fs_pwd(current->fs, mnt, dentry); out_putf: Index: linux-2.6/fs/udf/file.c =================================================================== --- linux-2.6.orig/fs/udf/file.c 2005-10-31 17:55:00.000000000 +0100 +++ linux-2.6/fs/udf/file.c 2005-10-31 17:55:19.000000000 +0100 @@ -186,7 +186,7 @@ { int result = -EINVAL; - if ( permission(inode, MAY_READ, NULL) != 0 ) + if ( file_permission(filp, MAY_READ) != 0 ) { udf_debug("no permission to access inode %lu\n", inode->i_ino); Index: linux-2.6/fs/namei.c =================================================================== --- linux-2.6.orig/fs/namei.c 2005-10-31 17:55:15.000000000 +0100 +++ linux-2.6/fs/namei.c 2005-10-31 17:55:19.000000000 +0100 @@ -271,6 +271,23 @@ return permission(nd->dentry->d_inode, mask, nd); } +/** + * file_permission - check for additional access rights to a given file + * @file: file to check access rights for + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on an already opened + * file. + * + * Note: + * Do not use this function in new code. All access checks should + * be done using vfs_permission(). + */ +int file_permission(struct file *file, int mask) +{ + return permission(file->f_dentry->d_inode, mask, NULL); +} + /* * get_write_access() gets write permission for a file. * put_write_access() releases this write permission. @@ -2551,6 +2568,7 @@ EXPORT_SYMBOL(path_walk); EXPORT_SYMBOL(permission); EXPORT_SYMBOL(vfs_permission); +EXPORT_SYMBOL(file_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create); EXPORT_SYMBOL(vfs_follow_link);