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author | Ingo Molnar <mingo@kernel.org> | 2016-05-05 10:01:49 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2016-05-05 10:01:49 +0300 |
commit | 64b7aad5798478ffff52e110878ccaae4c3aaa34 (patch) | |
tree | 211764492dba48c45cbf186c66efa320ab7540db /drivers/tty/pty.c | |
parent | 078194f8e9fe3cf54c8fd8bded48a1db5bd8eb8a (diff) | |
parent | 2548d546d40c0014efdde88a53bf7896e917dcce (diff) | |
download | linux-64b7aad5798478ffff52e110878ccaae4c3aaa34.tar.xz |
Merge branch 'sched/urgent' into sched/core, to pick up fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/tty/pty.c')
-rw-r--r-- | drivers/tty/pty.c | 63 |
1 files changed, 30 insertions, 33 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index e16a49b507ef..0058d9fbf931 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -663,14 +663,14 @@ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) /* this is called once with whichever end is closed last */ static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) { - struct inode *ptmx_inode; + struct pts_fs_info *fsi; if (tty->driver->subtype == PTY_TYPE_MASTER) - ptmx_inode = tty->driver_data; + fsi = tty->driver_data; else - ptmx_inode = tty->link->driver_data; - devpts_kill_index(ptmx_inode, tty->index); - devpts_del_ref(ptmx_inode); + fsi = tty->link->driver_data; + devpts_kill_index(fsi, tty->index); + devpts_put_ref(fsi); } static const struct tty_operations ptm_unix98_ops = { @@ -720,6 +720,7 @@ static const struct tty_operations pty_unix98_ops = { static int ptmx_open(struct inode *inode, struct file *filp) { + struct pts_fs_info *fsi; struct tty_struct *tty; struct inode *slave_inode; int retval; @@ -734,47 +735,41 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) return retval; + fsi = devpts_get_ref(inode, filp); + retval = -ENODEV; + if (!fsi) + goto out_free_file; + /* find a device that is not in use. */ mutex_lock(&devpts_mutex); - index = devpts_new_index(inode); - if (index < 0) { - retval = index; - mutex_unlock(&devpts_mutex); - goto err_file; - } - + index = devpts_new_index(fsi); mutex_unlock(&devpts_mutex); - mutex_lock(&tty_mutex); - tty = tty_init_dev(ptm_driver, index); + retval = index; + if (index < 0) + goto out_put_ref; - if (IS_ERR(tty)) { - retval = PTR_ERR(tty); - goto out; - } + mutex_lock(&tty_mutex); + tty = tty_init_dev(ptm_driver, index); /* The tty returned here is locked so we can safely drop the mutex */ mutex_unlock(&tty_mutex); - set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ - tty->driver_data = inode; + retval = PTR_ERR(tty); + if (IS_ERR(tty)) + goto out; /* - * In the case where all references to ptmx inode are dropped and we - * still have /dev/tty opened pointing to the master/slave pair (ptmx - * is closed/released before /dev/tty), we must make sure that the inode - * is still valid when we call the final pty_unix98_shutdown, thus we - * hold an additional reference to the ptmx inode. For the same /dev/tty - * last close case, we also need to make sure the super_block isn't - * destroyed (devpts instance unmounted), before /dev/tty is closed and - * on its release devpts_kill_index is called. + * From here on out, the tty is "live", and the index and + * fsi will be killed/put by the tty_release() */ - devpts_add_ref(inode); + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ + tty->driver_data = fsi; tty_add_file(tty, filp); - slave_inode = devpts_pty_new(inode, + slave_inode = devpts_pty_new(fsi, MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index, tty->link); if (IS_ERR(slave_inode)) { @@ -793,12 +788,14 @@ static int ptmx_open(struct inode *inode, struct file *filp) return 0; err_release: tty_unlock(tty); + // This will also put-ref the fsi tty_release(inode, filp); return retval; out: - mutex_unlock(&tty_mutex); - devpts_kill_index(inode, index); -err_file: + devpts_kill_index(fsi, index); +out_put_ref: + devpts_put_ref(fsi); +out_free_file: tty_free_file(filp); return retval; } |