From d57999e1527f0b0c818846dcba5a23015beb4823 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 15 Feb 2008 14:37:27 -0800 Subject: [PATCH] [PATCH] do namei_flags calculation inside open_namei() My end goal here is to make sure all users of may_open() return filps. This will ensure that we properly release mount write counts which were taken for the filp in may_open(). This patch moves the sys_open flags to namei flags calculation into fs/namei.c. We'll shortly be moving the nameidata_to_filp() calls into namei.c, and this gets the sys_open flags to a place where we can get at them when we need them. Acked-by: Al Viro Signed-off-by: Christoph Hellwig Signed-off-by: Dave Hansen Signed-off-by: Al Viro --- fs/namei.c | 43 ++++++++++++++++++++++++++++++++++--------- fs/open.c | 22 ++-------------------- 2 files changed, 36 insertions(+), 29 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 8cf9bb9c2fc0..c70dbf720109 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1677,7 +1677,12 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) return 0; } -static int open_namei_create(struct nameidata *nd, struct path *path, +/* + * Be careful about ever adding any more callers of this + * function. Its flags must be in the namei format, not + * what get passed to sys_open(). + */ +static int __open_namei_create(struct nameidata *nd, struct path *path, int flag, int mode) { int error; @@ -1695,27 +1700,47 @@ static int open_namei_create(struct nameidata *nd, struct path *path, return may_open(nd, 0, flag & ~O_TRUNC); } +/* + * Note that while the flag value (low two bits) for sys_open means: + * 00 - read-only + * 01 - write-only + * 10 - read-write + * 11 - special + * it is changed into + * 00 - no permissions needed + * 01 - read-permission + * 10 - write-permission + * 11 - read-write + * for the internal routines (ie open_namei()/follow_link() etc) + * This is more logical, and also allows the 00 "no perm needed" + * to be used for symlinks (where the permissions are checked + * later). + * +*/ +static inline int open_to_namei_flags(int flag) +{ + if ((flag+1) & O_ACCMODE) + flag++; + return flag; +} + /* * open_namei() * * namei for open - this is in fact almost the whole open-routine. * * Note that the low bits of "flag" aren't the same as in the open - * system call - they are 00 - no permissions needed - * 01 - read permission needed - * 10 - write permission needed - * 11 - read/write permissions needed - * which is a lot more logical, and also allows the "no perm" needed - * for symlinks (where the permissions are checked later). + * system call. See open_to_namei_flags(). * SMP-safe */ -int open_namei(int dfd, const char *pathname, int flag, +int open_namei(int dfd, const char *pathname, int open_flag, int mode, struct nameidata *nd) { int acc_mode, error; struct path path; struct dentry *dir; int count = 0; + int flag = open_to_namei_flags(open_flag); acc_mode = ACC_MODE(flag); @@ -1776,7 +1801,7 @@ do_last: /* Negative dentry, just create the file */ if (!path.dentry->d_inode) { - error = open_namei_create(nd, &path, flag, mode); + error = __open_namei_create(nd, &path, flag, mode); if (error) goto exit; return 0; diff --git a/fs/open.c b/fs/open.c index 3fa4e4ffce4c..5ab3f3f079c0 100644 --- a/fs/open.c +++ b/fs/open.c @@ -796,31 +796,13 @@ cleanup_file: return ERR_PTR(error); } -/* - * Note that while the flag value (low two bits) for sys_open means: - * 00 - read-only - * 01 - write-only - * 10 - read-write - * 11 - special - * it is changed into - * 00 - no permissions needed - * 01 - read-permission - * 10 - write-permission - * 11 - read-write - * for the internal routines (ie open_namei()/follow_link() etc). 00 is - * used by symlinks. - */ static struct file *do_filp_open(int dfd, const char *filename, int flags, int mode) { - int namei_flags, error; + int error; struct nameidata nd; - namei_flags = flags; - if ((namei_flags+1) & O_ACCMODE) - namei_flags++; - - error = open_namei(dfd, filename, namei_flags, mode, &nd); + error = open_namei(dfd, filename, flags, mode, &nd); if (!error) return nameidata_to_filp(&nd, flags);