[PATCH v2] tty: Remove __GFP_NOFAIL from tty_add_file()

From: Pekka Enberg
Date: Tue Aug 24 2010 - 00:54:41 EST


This patch removes __GFP_NOFAIL use from tty_add_file() and adds proper error
handling to the call-sites of the function.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
---
- v1 -> v2: Use devpts_kill_index() for tty_add_file() failures in
ptmx_open() as suggested by David Rientjes.

drivers/char/pty.c | 4 +++-
drivers/char/tty_io.c | 15 +++++++++++----
include/linux/tty.h | 2 +-
3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index c350d01..923a485 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -676,7 +676,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)

set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */

- tty_add_file(tty, filp);
+ retval = tty_add_file(tty, filp);
+ if (retval)
+ goto out;

retval = devpts_pty_new(inode, tty->link);
if (retval)
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 949067a..1587f93 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -194,12 +194,13 @@ static inline struct tty_struct *file_tty(struct file *file)
}

/* Associate a new file with the tty structure */
-void tty_add_file(struct tty_struct *tty, struct file *file)
+int tty_add_file(struct tty_struct *tty, struct file *file)
{
struct tty_file_private *priv;

- /* XXX: must implement proper error handling in callers */
- priv = kmalloc(sizeof(*priv), GFP_KERNEL|__GFP_NOFAIL);
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;

priv->tty = tty;
priv->file = file;
@@ -208,6 +209,8 @@ void tty_add_file(struct tty_struct *tty, struct file *file)
spin_lock(&tty_files_lock);
list_add(&priv->list, &tty->tty_files);
spin_unlock(&tty_files_lock);
+
+ return 0;
}

/* Delete file from its tty */
@@ -1875,7 +1878,11 @@ got_driver:
return PTR_ERR(tty);
}

- tty_add_file(tty, filp);
+ retval = tty_add_file(tty, filp);
+ if (retval) {
+ tty_unlock();
+ return retval;
+ }

check_tty_count(tty, "tty_open");
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 67d64e6..a3f4388 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -465,7 +465,7 @@ extern void proc_clear_tty(struct task_struct *p);
extern struct tty_struct *get_current_tty(void);
extern void tty_default_fops(struct file_operations *fops);
extern struct tty_struct *alloc_tty_struct(void);
-extern void tty_add_file(struct tty_struct *tty, struct file *file);
+extern int tty_add_file(struct tty_struct *tty, struct file *file);
extern void free_tty_struct(struct tty_struct *tty);
extern void initialize_tty_struct(struct tty_struct *tty,
struct tty_driver *driver, int idx);
--
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/