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gut do_filp_open() a bit more (do_last separation)

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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>
This commit is contained in:
Al Viro 2009-12-24 01:58:28 -05:00
parent 648fa8611d
commit fb1cc555d5
1 changed files with 103 additions and 68 deletions
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171
fs/namei.c
View File

@ -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: