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authorDave Hansen <haveblue@us.ibm.com>2008-02-15 14:37:27 -0800
committerAl Viro <viro@zeniv.linux.org.uk>2008-04-19 00:25:31 -0400
commitd57999e1527f0b0c818846dcba5a23015beb4823 (patch)
tree6cd6f1e773fb19b18531997131b0887f835dcf03 /fs/namei.c
parent3925e6fc1f774048404fdd910b0345b06c699eb4 (diff)
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[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 <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c43
1 files changed, 34 insertions, 9 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 8cf9bb9c2fc..c70dbf72010 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;
@@ -1696,26 +1701,46 @@ static int open_namei_create(struct nameidata *nd, struct path *path,
}
/*
+ * 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;