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authorAl Viro <viro@zeniv.linux.org.uk>2009-12-24 09:58:28 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2010-03-05 17:01:13 +0300
commitfb1cc555d533869910e20de4b8d5147570afdfad (patch)
tree99ee86c8370e28df0991a4ecd03677cb65704f01
parent648fa8611de3d4d43bbd64af3226679d2d0eb609 (diff)
downloadlinux-fb1cc555d533869910e20de4b8d5147570afdfad.tar.xz
gut do_filp_open() a bit more (do_last separation)
Brute-force separation of stuff reachable from do_last: with the exception of do_link:; just take all that crap to a helper function as-is and have it tell the caller if it has to go to do_link. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/namei.c171
1 files changed, 103 insertions, 68 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 60b74b3946a1..3c39fa1608c5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1645,6 +1645,104 @@ exit:
return ERR_PTR(error);
}
+static struct file *do_last(struct nameidata *nd, struct path *path,
+ int open_flag, int flag, int acc_mode,
+ int mode, const char *pathname,
+ struct dentry *dir, int *is_link)
+{
+ struct file *filp;
+ int error;
+
+ *is_link = 0;
+
+ error = PTR_ERR(path->dentry);
+ if (IS_ERR(path->dentry)) {
+ mutex_unlock(&dir->d_inode->i_mutex);
+ goto exit;
+ }
+
+ if (IS_ERR(nd->intent.open.file)) {
+ error = PTR_ERR(nd->intent.open.file);
+ goto exit_mutex_unlock;
+ }
+
+ /* Negative dentry, just create the file */
+ if (!path->dentry->d_inode) {
+ /*
+ * This write is needed to ensure that a
+ * ro->rw transition does not occur between
+ * the time when the file is created and when
+ * a permanent write count is taken through
+ * the 'struct file' in nameidata_to_filp().
+ */
+ error = mnt_want_write(nd->path.mnt);
+ if (error)
+ goto exit_mutex_unlock;
+ error = __open_namei_create(nd, path, open_flag, mode);
+ if (error) {
+ mnt_drop_write(nd->path.mnt);
+ goto exit;
+ }
+ filp = nameidata_to_filp(nd);
+ mnt_drop_write(nd->path.mnt);
+ if (nd->root.mnt)
+ path_put(&nd->root);
+ if (!IS_ERR(filp)) {
+ error = ima_file_check(filp, acc_mode);
+ if (error) {
+ fput(filp);
+ filp = ERR_PTR(error);
+ }
+ }
+ return filp;
+ }
+
+ /*
+ * It already exists.
+ */
+ mutex_unlock(&dir->d_inode->i_mutex);
+ audit_inode(pathname, path->dentry);
+
+ error = -EEXIST;
+ if (flag & O_EXCL)
+ goto exit_dput;
+
+ if (__follow_mount(path)) {
+ error = -ELOOP;
+ if (flag & O_NOFOLLOW)
+ goto exit_dput;
+ }
+
+ error = -ENOENT;
+ if (!path->dentry->d_inode)
+ goto exit_dput;
+ if (path->dentry->d_inode->i_op->follow_link) {
+ *is_link = 1;
+ return NULL;
+ }
+
+ path_to_nameidata(path, nd);
+ error = -EISDIR;
+ if (S_ISDIR(path->dentry->d_inode->i_mode))
+ goto exit;
+ filp = finish_open(nd, open_flag, flag, acc_mode);
+ if (nd->root.mnt)
+ path_put(&nd->root);
+ return filp;
+
+exit_mutex_unlock:
+ mutex_unlock(&dir->d_inode->i_mutex);
+exit_dput:
+ path_put_conditional(path, nd);
+exit:
+ if (!IS_ERR(nd->intent.open.file))
+ release_open_intent(nd);
+ if (nd->root.mnt)
+ path_put(&nd->root);
+ path_put(&nd->path);
+ return ERR_PTR(error);
+}
+
/*
* Note that the low bits of the passed in "open_flag"
* are not the same as in the local variable "flag". See
@@ -1661,6 +1759,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
int count = 0;
int flag = open_to_namei_flags(open_flag);
int force_reval = 0;
+ int is_link;
/*
* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
@@ -1754,82 +1853,18 @@ reval:
path.mnt = nd.path.mnt;
do_last:
- error = PTR_ERR(path.dentry);
- if (IS_ERR(path.dentry)) {
- mutex_unlock(&dir->d_inode->i_mutex);
- goto exit;
- }
-
- if (IS_ERR(nd.intent.open.file)) {
- error = PTR_ERR(nd.intent.open.file);
- goto exit_mutex_unlock;
- }
-
- /* Negative dentry, just create the file */
- if (!path.dentry->d_inode) {
- /*
- * This write is needed to ensure that a
- * ro->rw transition does not occur between
- * the time when the file is created and when
- * a permanent write count is taken through
- * the 'struct file' in nameidata_to_filp().
- */
- error = mnt_want_write(nd.path.mnt);
- if (error)
- goto exit_mutex_unlock;
- error = __open_namei_create(&nd, &path, open_flag, mode);
- if (error) {
- mnt_drop_write(nd.path.mnt);
- goto exit;
- }
- filp = nameidata_to_filp(&nd);
- mnt_drop_write(nd.path.mnt);
- if (nd.root.mnt)
- path_put(&nd.root);
- if (!IS_ERR(filp)) {
- error = ima_file_check(filp, acc_mode);
- if (error) {
- fput(filp);
- filp = ERR_PTR(error);
- }
- }
- return filp;
- }
-
- /*
- * It already exists.
- */
- mutex_unlock(&dir->d_inode->i_mutex);
- audit_inode(pathname, path.dentry);
-
- error = -EEXIST;
- if (flag & O_EXCL)
- goto exit_dput;
-
- if (__follow_mount(&path)) {
- error = -ELOOP;
- if (flag & O_NOFOLLOW)
- goto exit_dput;
- }
-
- error = -ENOENT;
- if (!path.dentry->d_inode)
- goto exit_dput;
- if (path.dentry->d_inode->i_op->follow_link)
+ filp = do_last(&nd, &path, open_flag, flag, acc_mode, mode,
+ pathname, dir, &is_link);
+ if (is_link)
goto do_link;
+ return filp;
- path_to_nameidata(&path, &nd);
- error = -EISDIR;
- if (S_ISDIR(path.dentry->d_inode->i_mode))
- goto exit;
ok:
filp = finish_open(&nd, open_flag, flag, acc_mode);
if (nd.root.mnt)
path_put(&nd.root);
return filp;
-exit_mutex_unlock:
- mutex_unlock(&dir->d_inode->i_mutex);
exit_dput:
path_put_conditional(&path, &nd);
exit: