diff options
author | Arnd Bergmann <arnd@arndb.de> | 2010-06-01 20:53:08 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-10 20:47:44 (GMT) |
commit | ddcd9fb66ae7f448b517242c10a31d4e17bcad45 (patch) | |
tree | 54c5894f3c1dd45580cd45c621bbeb9174da879b /drivers | |
parent | 203652192634c1fce5e79df0a8ff2fabfaefd3ab (diff) | |
download | linux-fsl-qoriq-ddcd9fb66ae7f448b517242c10a31d4e17bcad45.tar.xz |
tty: remove tty_lock_nested
This changes all remaining users of tty_lock_nested
to be non-recursive, which lets us kill this function.
As a consequence, we won't need to keep the lock count
any more, which allows more simplifications later.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/char/pty.c | 2 | ||||
-rw-r--r-- | drivers/char/selection.c | 4 | ||||
-rw-r--r-- | drivers/char/tty_io.c | 41 | ||||
-rw-r--r-- | drivers/char/tty_ldisc.c | 3 |
4 files changed, 24 insertions, 26 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c index de22ea9..f2d7a76 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -62,7 +62,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp) if (tty->driver == ptm_driver) devpts_pty_kill(tty->link); #endif - tty_vhangup(tty->link); + tty_vhangup_locked(tty->link); } } diff --git a/drivers/char/selection.c b/drivers/char/selection.c index 75889cd..ebae344 100644 --- a/drivers/char/selection.c +++ b/drivers/char/selection.c @@ -313,7 +313,8 @@ int paste_selection(struct tty_struct *tty) struct tty_ldisc *ld; DECLARE_WAITQUEUE(wait, current); - tty_lock_nested(); /* always called with BTM from vt_ioctl */ + /* always called with BTM from vt_ioctl */ + WARN_ON(!tty_locked()); acquire_console_sem(); poke_blanked_console(); @@ -343,6 +344,5 @@ int paste_selection(struct tty_struct *tty) __set_current_state(TASK_RUNNING); tty_ldisc_deref(ld); - tty_unlock(); return 0; } diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index bb22cf4..dcf7d36 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -492,10 +492,8 @@ EXPORT_SYMBOL_GPL(tty_wakeup); * tasklist_lock to walk task list for hangup event * ->siglock to protect ->signal/->sighand */ -static void do_tty_hangup(struct work_struct *work) +void tty_vhangup_locked(struct tty_struct *tty) { - struct tty_struct *tty = - container_of(work, struct tty_struct, hangup_work); struct file *cons_filp = NULL; struct file *filp, *f = NULL; struct task_struct *p; @@ -517,8 +515,6 @@ static void do_tty_hangup(struct work_struct *work) /* inuse_filps is protected by the single tty lock, this really needs to change if we want to flush the workqueue with the lock held */ - tty_lock_nested(); /* called with BTM held from pty_close and - others */ check_tty_count(tty, "do_tty_hangup"); file_list_lock(); @@ -598,11 +594,20 @@ static void do_tty_hangup(struct work_struct *work) */ set_bit(TTY_HUPPED, &tty->flags); tty_ldisc_enable(tty); - tty_unlock(); if (f) fput(f); } +static void do_tty_hangup(struct work_struct *work) +{ + struct tty_struct *tty = + container_of(work, struct tty_struct, hangup_work); + + tty_lock(); + tty_vhangup_locked(tty); + tty_unlock(); +} + /** * tty_hangup - trigger a hangup event * @tty: tty to hangup @@ -638,7 +643,9 @@ void tty_vhangup(struct tty_struct *tty) printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); #endif - do_tty_hangup(&tty->hangup_work); + tty_lock(); + tty_vhangup_locked(tty); + tty_unlock(); } EXPORT_SYMBOL(tty_vhangup); @@ -719,10 +726,12 @@ void disassociate_ctty(int on_exit) tty = get_current_tty(); if (tty) { tty_pgrp = get_pid(tty->pgrp); - tty_lock_nested(); /* see above */ - if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) - tty_vhangup(tty); - tty_unlock(); + if (on_exit) { + tty_lock(); + if (tty->driver->type != TTY_DRIVER_TYPE_PTY) + tty_vhangup_locked(tty); + tty_unlock(); + } tty_kref_put(tty); } else if (on_exit) { struct pid *old_pgrp; @@ -1213,18 +1222,14 @@ static int tty_driver_install_tty(struct tty_driver *driver, int ret; if (driver->ops->install) { - tty_lock_nested(); /* already called with BTM held */ ret = driver->ops->install(driver, tty); - tty_unlock(); return ret; } if (tty_init_termios(tty) == 0) { - tty_lock_nested(); tty_driver_kref_get(driver); tty->count++; driver->ttys[idx] = tty; - tty_unlock(); return 0; } return -ENOMEM; @@ -1317,15 +1322,11 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, struct tty_struct *tty; int retval; - tty_lock_nested(); /* always called with tty lock held already */ - /* Check if pty master is being opened multiple times */ if (driver->subtype == PTY_TYPE_MASTER && (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { - tty_unlock(); return ERR_PTR(-EIO); } - tty_unlock(); /* * First time open is complex, especially for PTY devices. @@ -1369,9 +1370,7 @@ release_mem_out: if (printk_ratelimit()) printk(KERN_INFO "tty_init_dev: ldisc open failed, " "clearing slot %d\n", idx); - tty_lock_nested(); release_tty(tty, idx); - tty_unlock(); return ERR_PTR(retval); } diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c index 0f49479..412f977 100644 --- a/drivers/char/tty_ldisc.c +++ b/drivers/char/tty_ldisc.c @@ -450,9 +450,8 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld) if (ld->ops->open) { int ret; /* BTM here locks versus a hangup event */ - tty_lock_nested(); /* always held here already */ + WARN_ON(!tty_locked()); ret = ld->ops->open(tty); - tty_unlock(); return ret; } return 0; |