fs/namei.c: get do_last() and friends return int

Same conventions as for ->atomic_open().  Trimmed the
forest of labels a bit, while we are at it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 70 insertions, 80 deletions

diff --git a/fs/namei.c b/fs/namei.c
index aaff8a862151..16256d915cb8 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2193,18 +2193,17 @@ static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
         return security_inode_create(dir->dentry->d_inode, dentry, mode);
 }
 
-static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
-                                struct path *path, struct file *file,
-                                const struct open_flags *op,
-                                bool *want_write, bool need_lookup,
-                                int *opened)
+static int atomic_open(struct nameidata *nd, struct dentry *dentry,
+                        struct path *path, struct file *file,
+                        const struct open_flags *op,
+                        bool *want_write, bool need_lookup,
+                        int *opened)
 {
         struct inode *dir =  nd->path.dentry->d_inode;
         unsigned open_flag = open_to_namei_flags(op->open_flag);
         umode_t mode;
         int error;
         int acc_mode;
-        struct file *filp = NULL;
         int create_error = 0;
         struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
 
@@ -2212,7 +2211,7 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 
         /* Don't create child dentry for a dead directory. */
         if (unlikely(IS_DEADDIR(dir))) {
-                filp = ERR_PTR(-ENOENT);
+                error = -ENOENT;
                 goto out;
         }
 
@@ -2276,7 +2275,6 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
         if (error < 0) {
                 if (create_error && error == -ENOENT)
                         error = create_error;
-                filp = ERR_PTR(error);
                 goto out;
         }
 
@@ -2288,7 +2286,7 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
 
         if (error) {    /* returned 1, that is */
                 if (WARN_ON(file->f_path.dentry == DENTRY_NOT_SET)) {
-                        filp = ERR_PTR(-EIO);
+                        error = -EIO;
                         goto out;
                 }
                 if (file->f_path.dentry) {
@@ -2302,27 +2300,24 @@ static struct file *atomic_open(struct nameidata *nd, struct dentry *dentry,
          * We didn't have the inode before the open, so check open permission
          * here.
          */
-        filp = file;
-        error = may_open(&filp->f_path, acc_mode, open_flag);
-        if (error) {
-                fput(filp);
-                filp = ERR_PTR(error);
-        }
+        error = may_open(&file->f_path, acc_mode, open_flag);
+        if (error)
+                fput(file);
 
 out:
         dput(dentry);
-        return filp;
+        return error;
 
 no_open:
         if (need_lookup) {
                 dentry = lookup_real(dir, dentry, nd);
                 if (IS_ERR(dentry))
-                        return ERR_CAST(dentry);
+                        return PTR_ERR(dentry);
 
                 if (create_error) {
                         int open_flag = op->open_flag;
 
-                        filp = ERR_PTR(create_error);
+                        error = create_error;
                         if ((open_flag & O_EXCL)) {
                                 if (!dentry->d_inode)
                                         goto out;
@@ -2338,7 +2333,7 @@ no_open:
 looked_up:
         path->dentry = dentry;
         path->mnt = nd->path.mnt;
-        return NULL;
+        return 1;
 }
 
 /*
@@ -2349,10 +2344,10 @@ looked_up:
  * Returns open file or NULL on success, error otherwise.  NULL means no open
  * was performed, only lookup.
  */
-static struct file *lookup_open(struct nameidata *nd, struct path *path,
-                                struct file *file,
-                                const struct open_flags *op,
-                                bool *want_write, int *opened)
+static int lookup_open(struct nameidata *nd, struct path *path,
+                        struct file *file,
+                        const struct open_flags *op,
+                        bool *want_write, int *opened)
 {
         struct dentry *dir = nd->path.dentry;
         struct inode *dir_inode = dir->d_inode;
@@ -2363,7 +2358,7 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
         *opened &= ~FILE_CREATED;
         dentry = lookup_dcache(&nd->last, dir, nd, &need_lookup);
         if (IS_ERR(dentry))
-                return ERR_CAST(dentry);
+                return PTR_ERR(dentry);
 
         /* Cached positive dentry: will open in f_op->open */
         if (!need_lookup && dentry->d_inode)
@@ -2379,7 +2374,7 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 
                 dentry = lookup_real(dir_inode, dentry, nd);
                 if (IS_ERR(dentry))
-                        return ERR_CAST(dentry);
+                        return PTR_ERR(dentry);
         }
 
         /* Negative dentry, just create the file */
@@ -2409,26 +2404,25 @@ static struct file *lookup_open(struct nameidata *nd, struct path *path,
 out_no_open:
         path->dentry = dentry;
         path->mnt = nd->path.mnt;
-        return NULL;
+        return 1;
 
 out_dput:
         dput(dentry);
-        return ERR_PTR(error);
+        return error;
 }
 
 /*
  * Handle the last step of open()
  */
-static struct file *do_last(struct nameidata *nd, struct path *path,
-                            struct file *file, const struct open_flags *op,
-                            int *opened, const char *pathname)
+static int do_last(struct nameidata *nd, struct path *path,
+                   struct file *file, const struct open_flags *op,
+                   int *opened, const char *pathname)
 {
         struct dentry *dir = nd->path.dentry;
         int open_flag = op->open_flag;
         bool will_truncate = (open_flag & O_TRUNC) != 0;
         bool want_write = false;
         int acc_mode = op->acc_mode;
-        struct file *filp;
         struct inode *inode;
         bool symlink_ok = false;
         struct path save_parent = { .dentry = NULL, .mnt = NULL };
@@ -2443,22 +2437,22 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
         case LAST_DOT:
                 error = handle_dots(nd, nd->last_type);
                 if (error)
-                        return ERR_PTR(error);
+                        return error;
                 /* fallthrough */
         case LAST_ROOT:
                 error = complete_walk(nd);
                 if (error)
-                        return ERR_PTR(error);
+                        return error;
                 audit_inode(pathname, nd->path.dentry);
                 if (open_flag & O_CREAT) {
                         error = -EISDIR;
-                        goto exit;
+                        goto out;
                 }
                 goto finish_open;
         case LAST_BIND:
                 error = complete_walk(nd);
                 if (error)
-                        return ERR_PTR(error);
+                        return error;
                 audit_inode(pathname, dir);
                 goto finish_open;
         }
@@ -2474,7 +2468,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                         goto finish_lookup;
 
                 if (error < 0)
-                        goto exit;
+                        goto out;
 
                 BUG_ON(nd->inode != dir->d_inode);
         } else {
@@ -2486,29 +2480,29 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
                  */
                 error = complete_walk(nd);
                 if (error)
-                        return ERR_PTR(error);
+                        return error;
 
                 audit_inode(pathname, dir);
                 error = -EISDIR;
                 /* trailing slashes? */
                 if (nd->last.name[nd->last.len])
-                        goto exit;
+                        goto out;
         }
 
 retry_lookup:
         mutex_lock(&dir->d_inode->i_mutex);
-        filp = lookup_open(nd, path, file, op, &want_write, opened);
+        error = lookup_open(nd, path, file, op, &want_write, opened);
         mutex_unlock(&dir->d_inode->i_mutex);
 
-        if (filp) {
-                if (IS_ERR(filp))
+        if (error <= 0) {
+                if (error)
                         goto out;
 
                 if ((*opened & FILE_CREATED) ||
-                    !S_ISREG(filp->f_path.dentry->d_inode->i_mode))
+                    !S_ISREG(file->f_path.dentry->d_inode->i_mode))
                         will_truncate = false;
 
-                audit_inode(pathname, filp->f_path.dentry);
+                audit_inode(pathname, file->f_path.dentry);
                 goto opened;
         }
 
@@ -2554,18 +2548,18 @@ finish_lookup:
         error = -ENOENT;
         if (!inode) {
                 path_to_nameidata(path, nd);
-                goto exit;
+                goto out;
         }
 
         if (should_follow_link(inode, !symlink_ok)) {
                 if (nd->flags & LOOKUP_RCU) {
                         if (unlikely(unlazy_walk(nd, path->dentry))) {
                                 error = -ECHILD;
-                                goto exit;
+                                goto out;
                         }
                 }
                 BUG_ON(inode != path->dentry->d_inode);
-                return NULL;
+                return 1;
         }
 
         if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) {
@@ -2581,14 +2575,14 @@ finish_lookup:
         error = complete_walk(nd);
         if (error) {
                 path_put(&save_parent);
-                return ERR_PTR(error);
+                return error;
         }
         error = -EISDIR;
         if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode))
-                goto exit;
+                goto out;
         error = -ENOTDIR;
         if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup)
-                goto exit;
+                goto out;
         audit_inode(pathname, nd->path.dentry);
 finish_open:
         if (!S_ISREG(nd->inode->i_mode))
@@ -2597,32 +2591,30 @@ finish_open:
         if (will_truncate) {
                 error = mnt_want_write(nd->path.mnt);
                 if (error)
-                        goto exit;
+                        goto out;
                 want_write = true;
         }
 finish_open_created:
         error = may_open(&nd->path, acc_mode, open_flag);
         if (error)
-                goto exit;
+                goto out;
         file->f_path.mnt = nd->path.mnt;
         error = finish_open(file, nd->path.dentry, NULL, opened);
         if (error) {
-                filp = ERR_PTR(error);
                 if (error == -EOPENSTALE)
                         goto stale_open;
                 goto out;
         }
-        filp = file;
 opened:
-        error = open_check_o_direct(filp);
+        error = open_check_o_direct(file);
         if (error)
                 goto exit_fput;
-        error = ima_file_check(filp, op->acc_mode);
+        error = ima_file_check(file, op->acc_mode);
         if (error)
                 goto exit_fput;
 
         if (will_truncate) {
-                error = handle_truncate(filp);
+                error = handle_truncate(file);
                 if (error)
                         goto exit_fput;
         }
@@ -2631,16 +2623,14 @@ out:
                 mnt_drop_write(nd->path.mnt);
         path_put(&save_parent);
         terminate_walk(nd);
-        return filp;
+        return error;
 
 exit_dput:
         path_put_conditional(path, nd);
-exit:
-        filp = ERR_PTR(error);
         goto out;
 exit_fput:
-        fput(filp);
-        goto exit;
+        fput(file);
+        goto out;
 
 stale_open:
         /* If no saved parent or already retried then can't retry */
@@ -2666,7 +2656,6 @@ static struct file *path_openat(int dfd, const char *pathname,
 {
         struct file *base = NULL;
         struct file *file;
-        struct file *res;
         struct path path;
         int opened = 0;
         int error;
@@ -2679,29 +2668,29 @@ static struct file *path_openat(int dfd, const char *pathname,
 
         error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base);
         if (unlikely(error))
-                goto out_filp;
+                goto out;
 
         current->total_link_count = 0;
         error = link_path_walk(pathname, nd);
         if (unlikely(error))
-                goto out_filp;
+                goto out;
 
-        res = do_last(nd, &path, file, op, &opened, pathname);
-        while (unlikely(!res)) { /* trailing symlink */
+        error = do_last(nd, &path, file, op, &opened, pathname);
+        while (unlikely(error > 0)) { /* trailing symlink */
                 struct path link = path;
                 void *cookie;
                 if (!(nd->flags & LOOKUP_FOLLOW)) {
                         path_put_conditional(&path, nd);
                         path_put(&nd->path);
-                        res = ERR_PTR(-ELOOP);
+                        error = -ELOOP;
                         break;
                 }
                 nd->flags |= LOOKUP_PARENT;
                 nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
                 error = follow_link(&link, nd, &cookie);
                 if (unlikely(error))
-                        goto out_filp;
-                res = do_last(nd, &path, file, op, &opened, pathname);
+                        break;
+                error = do_last(nd, &path, file, op, &opened, pathname);
                 put_link(nd, &link, cookie);
         }
 out:
@@ -2709,19 +2698,20 @@ out:
                 path_put(&nd->root);
         if (base)
                 fput(base);
-        if (!(opened & FILE_OPENED))
+        if (!(opened & FILE_OPENED)) {
+                BUG_ON(!error);
                 put_filp(file);
-        if (res == ERR_PTR(-EOPENSTALE)) {
-                if (flags & LOOKUP_RCU)
-                        res = ERR_PTR(-ECHILD);
-                else
-                        res = ERR_PTR(-ESTALE);
         }
-        return res;
-
-out_filp:
-        res = ERR_PTR(error);
-        goto out;
+        if (unlikely(error)) {
+                if (error == -EOPENSTALE) {
+                        if (flags & LOOKUP_RCU)
+                                error = -ECHILD;
+                        else
+                                error = -ESTALE;
+                }
+                file = ERR_PTR(error);
+        }
+        return file;
 }
 
 struct file *do_filp_open(int dfd, const char *pathname,