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authorChristoph Hellwig <hch@lst.de>2008-02-15 14:37:28 -0800
committerAl Viro <viro@zeniv.linux.org.uk>2008-04-19 00:25:32 -0400
commita70e65df8812c52252fa07a2eb92a46451a4427f (patch)
treeb8154bebeb898743e89aeeea5971b410c7e49bf7
parentd57999e1527f0b0c818846dcba5a23015beb4823 (diff)
[PATCH] merge open_namei() and do_filp_open()
open_namei() will, in the future, need to take mount write counts over its creation and truncation (via may_open()) operations. It needs to keep these write counts until any potential filp that is created gets __fput()'d. This gets complicated in the error handling and becomes very murky as to how far open_namei() actually got, and whether or not that mount write count was taken. That makes it a bad interface. All that the current do_filp_open() really does is allocate the nameidata on the stack, then call open_namei(). So, this merges those two functions and moves filp_open() over to namei.c so it can be close to its buddy: do_filp_open(). It also gets a kerneldoc comment in the process. Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/namei.c100
-rw-r--r--fs/open.c19
-rw-r--r--include/linux/fs.h3
3 files changed, 59 insertions, 63 deletions
diff --git a/fs/namei.c b/fs/namei.c
index c70dbf72010..a1f8bbbd58e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1725,17 +1725,13 @@ static inline int open_to_namei_flags(int 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. See open_to_namei_flags().
- * SMP-safe
*/
-int open_namei(int dfd, const char *pathname, int open_flag,
- int mode, struct nameidata *nd)
+struct file *do_filp_open(int dfd, const char *pathname,
+ int open_flag, int mode)
{
+ struct nameidata nd;
int acc_mode, error;
struct path path;
struct dentry *dir;
@@ -1758,18 +1754,19 @@ int open_namei(int dfd, const char *pathname, int open_flag,
*/
if (!(flag & O_CREAT)) {
error = path_lookup_open(dfd, pathname, lookup_flags(flag),
- nd, flag);
+ &nd, flag);
if (error)
- return error;
+ return ERR_PTR(error);
goto ok;
}
/*
* Create - we need to know the parent.
*/
- error = path_lookup_create(dfd,pathname,LOOKUP_PARENT,nd,flag,mode);
+ error = path_lookup_create(dfd, pathname, LOOKUP_PARENT,
+ &nd, flag, mode);
if (error)
- return error;
+ return ERR_PTR(error);
/*
* We have the parent and last component. First of all, check
@@ -1777,14 +1774,14 @@ int open_namei(int dfd, const char *pathname, int open_flag,
* will not do.
*/
error = -EISDIR;
- if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len])
+ if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len])
goto exit;
- dir = nd->path.dentry;
- nd->flags &= ~LOOKUP_PARENT;
+ dir = nd.path.dentry;
+ nd.flags &= ~LOOKUP_PARENT;
mutex_lock(&dir->d_inode->i_mutex);
- path.dentry = lookup_hash(nd);
- path.mnt = nd->path.mnt;
+ path.dentry = lookup_hash(&nd);
+ path.mnt = nd.path.mnt;
do_last:
error = PTR_ERR(path.dentry);
@@ -1793,18 +1790,18 @@ do_last:
goto exit;
}
- if (IS_ERR(nd->intent.open.file)) {
+ if (IS_ERR(nd.intent.open.file)) {
mutex_unlock(&dir->d_inode->i_mutex);
- error = PTR_ERR(nd->intent.open.file);
+ error = PTR_ERR(nd.intent.open.file);
goto exit_dput;
}
/* 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;
+ return nameidata_to_filp(&nd, open_flag);
}
/*
@@ -1829,23 +1826,23 @@ do_last:
if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link)
goto do_link;
- path_to_nameidata(&path, nd);
+ path_to_nameidata(&path, &nd);
error = -EISDIR;
if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode))
goto exit;
ok:
- error = may_open(nd, acc_mode, flag);
+ error = may_open(&nd, acc_mode, flag);
if (error)
goto exit;
- return 0;
+ return nameidata_to_filp(&nd, open_flag);
exit_dput:
- path_put_conditional(&path, nd);
+ path_put_conditional(&path, &nd);
exit:
- if (!IS_ERR(nd->intent.open.file))
- release_open_intent(nd);
- path_put(&nd->path);
- return error;
+ if (!IS_ERR(nd.intent.open.file))
+ release_open_intent(&nd);
+ path_put(&nd.path);
+ return ERR_PTR(error);
do_link:
error = -ELOOP;
@@ -1861,43 +1858,60 @@ do_link:
* stored in nd->last.name and we will have to putname() it when we
* are done. Procfs-like symlinks just set LAST_BIND.
*/
- nd->flags |= LOOKUP_PARENT;
- error = security_inode_follow_link(path.dentry, nd);
+ nd.flags |= LOOKUP_PARENT;
+ error = security_inode_follow_link(path.dentry, &nd);
if (error)
goto exit_dput;
- error = __do_follow_link(&path, nd);
+ error = __do_follow_link(&path, &nd);
if (error) {
/* Does someone understand code flow here? Or it is only
* me so stupid? Anathema to whoever designed this non-sense
* with "intent.open".
*/
- release_open_intent(nd);
- return error;
+ release_open_intent(&nd);
+ return ERR_PTR(error);
}
- nd->flags &= ~LOOKUP_PARENT;
- if (nd->last_type == LAST_BIND)
+ nd.flags &= ~LOOKUP_PARENT;
+ if (nd.last_type == LAST_BIND)
goto ok;
error = -EISDIR;
- if (nd->last_type != LAST_NORM)
+ if (nd.last_type != LAST_NORM)
goto exit;
- if (nd->last.name[nd->last.len]) {
- __putname(nd->last.name);
+ if (nd.last.name[nd.last.len]) {
+ __putname(nd.last.name);
goto exit;
}
error = -ELOOP;
if (count++==32) {
- __putname(nd->last.name);
+ __putname(nd.last.name);
goto exit;
}
- dir = nd->path.dentry;
+ dir = nd.path.dentry;
mutex_lock(&dir->d_inode->i_mutex);
- path.dentry = lookup_hash(nd);
- path.mnt = nd->path.mnt;
- __putname(nd->last.name);
+ path.dentry = lookup_hash(&nd);
+ path.mnt = nd.path.mnt;
+ __putname(nd.last.name);
goto do_last;
}
/**
+ * filp_open - open file and return file pointer
+ *
+ * @filename: path to open
+ * @flags: open flags as per the open(2) second argument
+ * @mode: mode for the new file if O_CREAT is set, else ignored
+ *
+ * This is the helper to open a file from kernelspace if you really
+ * have to. But in generally you should not do this, so please move
+ * along, nothing to see here..
+ */
+struct file *filp_open(const char *filename, int flags, int mode)
+{
+ return do_filp_open(AT_FDCWD, filename, flags, mode);
+}
+EXPORT_SYMBOL(filp_open);
+
+/**
* lookup_create - lookup a dentry, creating it if it doesn't exist
* @nd: nameidata info
* @is_dir: directory flag
diff --git a/fs/open.c b/fs/open.c
index 5ab3f3f079c..8111947905d 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -796,25 +796,6 @@ cleanup_file:
return ERR_PTR(error);
}
-static struct file *do_filp_open(int dfd, const char *filename, int flags,
- int mode)
-{
- int error;
- struct nameidata nd;
-
- error = open_namei(dfd, filename, flags, mode, &nd);
- if (!error)
- return nameidata_to_filp(&nd, flags);
-
- return ERR_PTR(error);
-}
-
-struct file *filp_open(const char *filename, int flags, int mode)
-{
- return do_filp_open(AT_FDCWD, filename, flags, mode);
-}
-EXPORT_SYMBOL(filp_open);
-
/**
* lookup_instantiate_filp - instantiates the open intent filp
* @nd: pointer to nameidata
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b84b848431f..013b9c2b88e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1735,7 +1735,8 @@ extern struct file *create_read_pipe(struct file *f);
extern struct file *create_write_pipe(void);
extern void free_write_pipe(struct file *);
-extern int open_namei(int dfd, const char *, int, int, struct nameidata *);
+extern struct file *do_filp_open(int dfd, const char *pathname,
+ int open_flag, int mode);
extern int may_open(struct nameidata *, int, int);
extern int kernel_read(struct file *, unsigned long, char *, unsigned long);