From 684999149002dd046269666a390458e0acb38280 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Fri, 6 Feb 2009 13:52:43 -0700 Subject: [PATCH 1/4] Rename struct file->f_ep_lock This lock moves out of the CONFIG_EPOLL ifdef and becomes f_lock. For now, epoll remains the only user, but a future patch will use it to protect f_flags as well. Cc: Davide Libenzi Reviewed-by: Christoph Hellwig Signed-off-by: Jonathan Corbet --- fs/eventpoll.c | 12 +++++++----- fs/file_table.c | 1 + include/linux/eventpoll.h | 1 - include/linux/fs.h | 2 +- 4 files changed, 9 insertions(+), 7 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 011b9b8c90c..c5c424f23fd 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -417,10 +417,10 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi) ep_unregister_pollwait(ep, epi); /* Remove the current item from the list of epoll hooks */ - spin_lock(&file->f_ep_lock); + spin_lock(&file->f_lock); if (ep_is_linked(&epi->fllink)) list_del_init(&epi->fllink); - spin_unlock(&file->f_ep_lock); + spin_unlock(&file->f_lock); rb_erase(&epi->rbn, &ep->rbr); @@ -538,7 +538,7 @@ void eventpoll_release_file(struct file *file) struct epitem *epi; /* - * We don't want to get "file->f_ep_lock" because it is not + * We don't want to get "file->f_lock" because it is not * necessary. It is not necessary because we're in the "struct file" * cleanup path, and this means that noone is using this file anymore. * So, for example, epoll_ctl() cannot hit here sicne if we reach this @@ -547,6 +547,8 @@ void eventpoll_release_file(struct file *file) * will correctly serialize the operation. We do need to acquire * "ep->mtx" after "epmutex" because ep_remove() requires it when called * from anywhere but ep_free(). + * + * Besides, ep_remove() acquires the lock, so we can't hold it here. */ mutex_lock(&epmutex); @@ -785,9 +787,9 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event, goto error_unregister; /* Add the current item to the list of active epoll hook for this file */ - spin_lock(&tfile->f_ep_lock); + spin_lock(&tfile->f_lock); list_add_tail(&epi->fllink, &tfile->f_ep_links); - spin_unlock(&tfile->f_ep_lock); + spin_unlock(&tfile->f_lock); /* * Add the current item to the RB tree. All RB tree operations are diff --git a/fs/file_table.c b/fs/file_table.c index bbeeac6efa1..aa1e1805028 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -127,6 +127,7 @@ struct file *get_empty_filp(void) atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); f->f_cred = get_cred(cred); + spin_lock_init(&f->f_lock); eventpoll_init_file(f); /* f->f_version: 0 */ return f; diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h index f1e1d3c4712..f6856a5a1d4 100644 --- a/include/linux/eventpoll.h +++ b/include/linux/eventpoll.h @@ -61,7 +61,6 @@ struct file; static inline void eventpoll_init_file(struct file *file) { INIT_LIST_HEAD(&file->f_ep_links); - spin_lock_init(&file->f_ep_lock); } diff --git a/include/linux/fs.h b/include/linux/fs.h index 92734c0012e..2011600d12c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -848,6 +848,7 @@ struct file { #define f_dentry f_path.dentry #define f_vfsmnt f_path.mnt const struct file_operations *f_op; + spinlock_t f_lock; /* f_ep_links */ atomic_long_t f_count; unsigned int f_flags; fmode_t f_mode; @@ -866,7 +867,6 @@ struct file { #ifdef CONFIG_EPOLL /* Used by fs/eventpoll.c to link all the hooks to this file */ struct list_head f_ep_links; - spinlock_t f_ep_lock; #endif /* #ifdef CONFIG_EPOLL */ struct address_space *f_mapping; #ifdef CONFIG_DEBUG_WRITECOUNT From db1dd4d376134eba0e08af523b61cc566a4ea1cd Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Fri, 6 Feb 2009 15:25:24 -0700 Subject: [PATCH 2/4] Use f_lock to protect f_flags Traditionally, changes to struct file->f_flags have been done under BKL protection, or with no protection at all. This patch causes all f_flags changes after file open/creation time to be done under protection of f_lock. This allows the removal of some BKL usage and fixes a number of longstanding (if microscopic) races. Reviewed-by: Christoph Hellwig Cc: Al Viro Signed-off-by: Jonathan Corbet --- drivers/char/tty_io.c | 5 ++--- drivers/usb/gadget/file_storage.c | 7 ++++++- fs/fcntl.c | 2 ++ fs/ioctl.c | 7 ++++--- fs/nfsd/vfs.c | 5 ++++- include/linux/fs.h | 2 +- ipc/mqueue.c | 2 ++ sound/core/oss/pcm_oss.c | 2 ++ sound/oss/au1550_ac97.c | 2 ++ sound/oss/audio.c | 2 ++ sound/oss/sh_dac_audio.c | 2 ++ sound/oss/swarm_cs4297a.c | 2 ++ sound/oss/vwsnd.c | 2 ++ 13 files changed, 33 insertions(+), 9 deletions(-) diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index bc84e125c6b..224f271d8cb 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -2162,13 +2162,12 @@ static int fionbio(struct file *file, int __user *p) if (get_user(nonblock, p)) return -EFAULT; - /* file->f_flags is still BKL protected in the fs layer - vomit */ - lock_kernel(); + spin_lock(&file->f_lock); if (nonblock) file->f_flags |= O_NONBLOCK; else file->f_flags &= ~O_NONBLOCK; - unlock_kernel(); + spin_unlock(&file->f_lock); return 0; } diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c index 1ab9dac7e12..33bb76cef33 100644 --- a/drivers/usb/gadget/file_storage.c +++ b/drivers/usb/gadget/file_storage.c @@ -1711,7 +1711,9 @@ static int do_write(struct fsg_dev *fsg) curlun->sense_data = SS_WRITE_PROTECTED; return -EINVAL; } + spin_lock(&curlun->filp->f_lock); curlun->filp->f_flags &= ~O_SYNC; // Default is not to wait + spin_unlock(&curlun->filp->f_lock); /* Get the starting Logical Block Address and check that it's * not too big */ @@ -1728,8 +1730,11 @@ static int do_write(struct fsg_dev *fsg) curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } - if (fsg->cmnd[1] & 0x08) // FUA + if (fsg->cmnd[1] & 0x08) { // FUA + spin_lock(&curlun->filp->f_lock); curlun->filp->f_flags |= O_SYNC; + spin_unlock(&curlun->filp->f_lock); + } } if (lba >= curlun->num_sectors) { curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE; diff --git a/fs/fcntl.c b/fs/fcntl.c index bd215cc791d..04df8570a2d 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -189,7 +189,9 @@ static int setfl(int fd, struct file * filp, unsigned long arg) } } + spin_lock(&filp->f_lock); filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); + spin_unlock(&filp->f_lock); out: unlock_kernel(); return error; diff --git a/fs/ioctl.c b/fs/ioctl.c index 240ec63984c..421aab465da 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -404,10 +404,12 @@ static int ioctl_fionbio(struct file *filp, int __user *argp) if (O_NONBLOCK != O_NDELAY) flag |= O_NDELAY; #endif + spin_lock(&filp->f_lock); if (on) filp->f_flags |= flag; else filp->f_flags &= ~flag; + spin_unlock(&filp->f_lock); return error; } @@ -432,10 +434,12 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp, if (error) return error; + spin_lock(&filp->f_lock); if (on) filp->f_flags |= FASYNC; else filp->f_flags &= ~FASYNC; + spin_unlock(&filp->f_lock); return error; } @@ -499,10 +503,7 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, break; case FIONBIO: - /* BKL needed to avoid races tweaking f_flags */ - lock_kernel(); error = ioctl_fionbio(filp, argp); - unlock_kernel(); break; case FIOASYNC: diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 6e50aaa56ca..c165a6403df 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -998,8 +998,11 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, if (!EX_ISSYNC(exp)) stable = 0; - if (stable && !EX_WGATHER(exp)) + if (stable && !EX_WGATHER(exp)) { + spin_lock(&file->f_lock); file->f_flags |= O_SYNC; + spin_unlock(&file->f_lock); + } /* Write the data. */ oldfs = get_fs(); set_fs(KERNEL_DS); diff --git a/include/linux/fs.h b/include/linux/fs.h index 2011600d12c..7428c6d35e6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -848,7 +848,7 @@ struct file { #define f_dentry f_path.dentry #define f_vfsmnt f_path.mnt const struct file_operations *f_op; - spinlock_t f_lock; /* f_ep_links */ + spinlock_t f_lock; /* f_ep_links, f_flags */ atomic_long_t f_count; unsigned int f_flags; fmode_t f_mode; diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 54b4077fed7..a8ddadbc745 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -1156,10 +1156,12 @@ SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, omqstat.mq_flags = filp->f_flags & O_NONBLOCK; if (u_mqstat) { audit_mq_getsetattr(mqdes, &mqstat); + spin_lock(&filp->f_lock); if (mqstat.mq_flags & O_NONBLOCK) filp->f_flags |= O_NONBLOCK; else filp->f_flags &= ~O_NONBLOCK; + spin_unlock(&filp->f_lock); inode->i_atime = inode->i_ctime = CURRENT_TIME; } diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index 0a1798eafb0..d4460f18e76 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1895,7 +1895,9 @@ static int snd_pcm_oss_set_fragment(struct snd_pcm_oss_file *pcm_oss_file, unsig static int snd_pcm_oss_nonblock(struct file * file) { + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; } diff --git a/sound/oss/au1550_ac97.c b/sound/oss/au1550_ac97.c index 81e1f443d09..4191acccbcd 100644 --- a/sound/oss/au1550_ac97.c +++ b/sound/oss/au1550_ac97.c @@ -1627,7 +1627,9 @@ au1550_ioctl(struct inode *inode, struct file *file, unsigned int cmd, sizeof(abinfo)) ? -EFAULT : 0; case SNDCTL_DSP_NONBLOCK: + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_GETODELAY: diff --git a/sound/oss/audio.c b/sound/oss/audio.c index 89bd27a5e86..b69c05b7ea7 100644 --- a/sound/oss/audio.c +++ b/sound/oss/audio.c @@ -433,7 +433,9 @@ int audio_ioctl(int dev, struct file *file, unsigned int cmd, void __user *arg) return dma_ioctl(dev, cmd, arg); case SNDCTL_DSP_NONBLOCK: + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_GETCAPS: diff --git a/sound/oss/sh_dac_audio.c b/sound/oss/sh_dac_audio.c index e5d42399491..78cfb66e4c5 100644 --- a/sound/oss/sh_dac_audio.c +++ b/sound/oss/sh_dac_audio.c @@ -135,7 +135,9 @@ static int dac_audio_ioctl(struct inode *inode, struct file *file, return put_user(AFMT_U8, (int *)arg); case SNDCTL_DSP_NONBLOCK: + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_GETCAPS: diff --git a/sound/oss/swarm_cs4297a.c b/sound/oss/swarm_cs4297a.c index 41562ecde5b..1edab7b4ea8 100644 --- a/sound/oss/swarm_cs4297a.c +++ b/sound/oss/swarm_cs4297a.c @@ -2200,7 +2200,9 @@ static int cs4297a_ioctl(struct inode *inode, struct file *file, sizeof(abinfo)) ? -EFAULT : 0; case SNDCTL_DSP_NONBLOCK: + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_GETODELAY: diff --git a/sound/oss/vwsnd.c b/sound/oss/vwsnd.c index 78b8acc7c3b..187f72750e8 100644 --- a/sound/oss/vwsnd.c +++ b/sound/oss/vwsnd.c @@ -2673,7 +2673,9 @@ static int vwsnd_audio_do_ioctl(struct inode *inode, case SNDCTL_DSP_NONBLOCK: /* _SIO ('P',14) */ DBGX("SNDCTL_DSP_NONBLOCK\n"); + spin_lock(&file->f_lock); file->f_flags |= O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; case SNDCTL_DSP_RESET: /* _SIO ('P', 0) */ From 76398425bb06b07cc3a3b1ce169c67dc9d6874ed Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 1 Feb 2009 14:26:59 -0700 Subject: [PATCH 3/4] Move FASYNC bit handling to f_op->fasync() Removing the BKL from FASYNC handling ran into the challenge of keeping the setting of the FASYNC bit in filp->f_flags atomic with regard to calls to the underlying fasync() function. Andi Kleen suggested moving the handling of that bit into fasync(); this patch does exactly that. As a result, we have a couple of internal API changes: fasync() must now manage the FASYNC bit, and it will be called without the BKL held. As it happens, every fasync() implementation in the kernel with one exception calls fasync_helper(). So, if we make fasync_helper() set the FASYNC bit, we can avoid making any changes to the other fasync() functions - as long as those functions, themselves, have proper locking. Most fasync() implementations do nothing but call fasync_helper() - which has its own lock - so they are easily verified as correct. The BKL had already been pushed down into the rest. The networking code has its own version of fasync_helper(), so that code has been augmented with explicit FASYNC bit handling. Cc: Al Viro Cc: David Miller Reviewed-by: Christoph Hellwig Signed-off-by: Jonathan Corbet --- Documentation/filesystems/Locking | 7 +++++-- fs/fcntl.c | 29 ++++++++++++++++------------- fs/ioctl.c | 13 +------------ net/socket.c | 7 +++++++ 4 files changed, 29 insertions(+), 27 deletions(-) diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index ec6a9392a17..4e78ce67784 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -437,8 +437,11 @@ grab BKL for cases when we close a file that had been opened r/w, but that can and should be done using the internal locking with smaller critical areas). Current worst offender is ext2_get_block()... -->fasync() is a mess. This area needs a big cleanup and that will probably -affect locking. +->fasync() is called without BKL protection, and is responsible for +maintaining the FASYNC bit in filp->f_flags. Most instances call +fasync_helper(), which does that maintenance, so it's not normally +something one needs to worry about. Return values > 0 will be mapped to +zero in the VFS layer. ->readdir() and ->ioctl() on directories must be changed. Ideally we would move ->readdir() to inode_operations and use a separate method for directory diff --git a/fs/fcntl.c b/fs/fcntl.c index 04df8570a2d..431bb645927 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -141,7 +141,7 @@ SYSCALL_DEFINE1(dup, unsigned int, fildes) return ret; } -#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME) +#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | O_DIRECT | O_NOATIME) static int setfl(int fd, struct file * filp, unsigned long arg) { @@ -177,23 +177,19 @@ static int setfl(int fd, struct file * filp, unsigned long arg) return error; /* - * We still need a lock here for now to keep multiple FASYNC calls - * from racing with each other. + * ->fasync() is responsible for setting the FASYNC bit. */ - lock_kernel(); - if ((arg ^ filp->f_flags) & FASYNC) { - if (filp->f_op && filp->f_op->fasync) { - error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); - if (error < 0) - goto out; - } + if (((arg ^ filp->f_flags) & FASYNC) && filp->f_op && + filp->f_op->fasync) { + error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); + if (error < 0) + goto out; } - spin_lock(&filp->f_lock); filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); spin_unlock(&filp->f_lock); + out: - unlock_kernel(); return error; } @@ -518,7 +514,7 @@ static DEFINE_RWLOCK(fasync_lock); static struct kmem_cache *fasync_cache __read_mostly; /* - * fasync_helper() is used by some character device drivers (mainly mice) + * fasync_helper() is used by almost all character device drivers * to set up the fasync queue. It returns negative on error, 0 if it did * no changes and positive if it added/deleted the entry. */ @@ -557,6 +553,13 @@ int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fap result = 1; } out: + /* Fix up FASYNC bit while still holding fasync_lock */ + spin_lock(&filp->f_lock); + if (on) + filp->f_flags |= FASYNC; + else + filp->f_flags &= ~FASYNC; + spin_unlock(&filp->f_lock); write_unlock_irq(&fasync_lock); return result; } diff --git a/fs/ioctl.c b/fs/ioctl.c index 421aab465da..e8e89edba57 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -427,19 +427,11 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp, /* Did FASYNC state change ? */ if ((flag ^ filp->f_flags) & FASYNC) { if (filp->f_op && filp->f_op->fasync) + /* fasync() adjusts filp->f_flags */ error = filp->f_op->fasync(fd, filp, on); else error = -ENOTTY; } - if (error) - return error; - - spin_lock(&filp->f_lock); - if (on) - filp->f_flags |= FASYNC; - else - filp->f_flags &= ~FASYNC; - spin_unlock(&filp->f_lock); return error; } @@ -507,10 +499,7 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, break; case FIOASYNC: - /* BKL needed to avoid races tweaking f_flags */ - lock_kernel(); error = ioctl_fioasync(fd, filp, argp); - unlock_kernel(); break; case FIOQSIZE: diff --git a/net/socket.c b/net/socket.c index 35dd7371752..0f75746ab06 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1030,6 +1030,13 @@ static int sock_fasync(int fd, struct file *filp, int on) lock_sock(sk); + spin_lock(&filp->f_lock); + if (on) + filp->f_flags |= FASYNC; + else + filp->f_flags &= ~FASYNC; + spin_unlock(&filp->f_lock); + prev = &(sock->fasync_list); for (fa = *prev; fa != NULL; prev = &fa->fa_next, fa = *prev) From 60aa49243d09afc873f082567d2e3c16634ced84 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 1 Feb 2009 14:52:56 -0700 Subject: [PATCH 4/4] Rationalize fasync return values Most fasync implementations do something like: return fasync_helper(...); But fasync_helper() will return a positive value at times - a feature used in at least one place. Thus, a number of other drivers do: err = fasync_helper(...); if (err < 0) return err; return 0; In the interests of consistency and more concise code, it makes sense to map positive return values onto zero where ->fasync() is called. Cc: Al Viro Signed-off-by: Jonathan Corbet --- drivers/char/sonypi.c | 7 +------ drivers/gpu/drm/drm_fops.c | 6 +----- drivers/hid/usbhid/hiddev.c | 5 +---- drivers/ieee1394/dv1394.c | 6 +----- drivers/input/evdev.c | 5 +---- drivers/input/joydev.c | 5 +---- drivers/input/mousedev.c | 5 +---- drivers/input/serio/serio_raw.c | 4 +--- drivers/net/wan/cosa.c | 4 ++-- drivers/platform/x86/sony-laptop.c | 7 +------ drivers/scsi/sg.c | 4 +--- fs/fcntl.c | 2 ++ fs/ioctl.c | 2 +- fs/pipe.c | 16 +++------------- sound/core/control.c | 7 ++----- sound/core/pcm_native.c | 4 +--- sound/core/timer.c | 6 +----- 17 files changed, 22 insertions(+), 73 deletions(-) diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c index f4374437a03..fd3dced9777 100644 --- a/drivers/char/sonypi.c +++ b/drivers/char/sonypi.c @@ -888,12 +888,7 @@ found: static int sonypi_misc_fasync(int fd, struct file *filp, int on) { - int retval; - - retval = fasync_helper(fd, filp, on, &sonypi_device.fifo_async); - if (retval < 0) - return retval; - return 0; + return fasync_helper(fd, filp, on, &sonypi_device.fifo_async); } static int sonypi_misc_release(struct inode *inode, struct file *file) diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index f52663ebe01..e13cb62bbae 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -337,14 +337,10 @@ int drm_fasync(int fd, struct file *filp, int on) { struct drm_file *priv = filp->private_data; struct drm_device *dev = priv->minor->dev; - int retcode; DRM_DEBUG("fd = %d, device = 0x%lx\n", fd, (long)old_encode_dev(priv->minor->device)); - retcode = fasync_helper(fd, filp, on, &dev->buf_async); - if (retcode < 0) - return retcode; - return 0; + return fasync_helper(fd, filp, on, &dev->buf_async); } EXPORT_SYMBOL(drm_fasync); diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index 4940e4d70c2..3a7b4fe192a 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -227,12 +227,9 @@ void hiddev_report_event(struct hid_device *hid, struct hid_report *report) */ static int hiddev_fasync(int fd, struct file *file, int on) { - int retval; struct hiddev_list *list = file->private_data; - retval = fasync_helper(fd, file, on, &list->fasync); - - return retval < 0 ? retval : 0; + return fasync_helper(fd, file, on, &list->fasync); } diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c index 3838bc4acab..cb15bfa38d7 100644 --- a/drivers/ieee1394/dv1394.c +++ b/drivers/ieee1394/dv1394.c @@ -1325,11 +1325,7 @@ static int dv1394_fasync(int fd, struct file *file, int on) struct video_card *video = file_to_video_card(file); - int retval = fasync_helper(fd, file, on, &video->fasync); - - if (retval < 0) - return retval; - return 0; + return fasync_helper(fd, file, on, &video->fasync); } static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index ed8baa0aec3..7a7a026ba71 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -94,11 +94,8 @@ static void evdev_event(struct input_handle *handle, static int evdev_fasync(int fd, struct file *file, int on) { struct evdev_client *client = file->private_data; - int retval; - retval = fasync_helper(fd, file, on, &client->fasync); - - return retval < 0 ? retval : 0; + return fasync_helper(fd, file, on, &client->fasync); } static int evdev_flush(struct file *file, fl_owner_t id) diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c index 6f2366220a5..4224f011284 100644 --- a/drivers/input/joydev.c +++ b/drivers/input/joydev.c @@ -159,12 +159,9 @@ static void joydev_event(struct input_handle *handle, static int joydev_fasync(int fd, struct file *file, int on) { - int retval; struct joydev_client *client = file->private_data; - retval = fasync_helper(fd, file, on, &client->fasync); - - return retval < 0 ? retval : 0; + return fasync_helper(fd, file, on, &client->fasync); } static void joydev_free(struct device *dev) diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c index ef99a7e6d40..17fd6d46d08 100644 --- a/drivers/input/mousedev.c +++ b/drivers/input/mousedev.c @@ -403,12 +403,9 @@ static void mousedev_event(struct input_handle *handle, static int mousedev_fasync(int fd, struct file *file, int on) { - int retval; struct mousedev_client *client = file->private_data; - retval = fasync_helper(fd, file, on, &client->fasync); - - return retval < 0 ? retval : 0; + return fasync_helper(fd, file, on, &client->fasync); } static void mousedev_free(struct device *dev) diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c index 06bbd0e74c6..b03009bb746 100644 --- a/drivers/input/serio/serio_raw.c +++ b/drivers/input/serio/serio_raw.c @@ -58,10 +58,8 @@ static unsigned int serio_raw_no; static int serio_raw_fasync(int fd, struct file *file, int on) { struct serio_raw_list *list = file->private_data; - int retval; - retval = fasync_helper(fd, file, on, &list->fasync); - return retval < 0 ? retval : 0; + return fasync_helper(fd, file, on, &list->fasync); } static struct serio_raw *serio_raw_locate(int minor) diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c index d80b72e22de..ce753e9c576 100644 --- a/drivers/net/wan/cosa.c +++ b/drivers/net/wan/cosa.c @@ -993,8 +993,8 @@ static struct fasync_struct *fasync[256] = { NULL, }; static int cosa_fasync(struct inode *inode, struct file *file, int on) { int port = iminor(inode); - int rv = fasync_helper(inode, file, on, &fasync[port]); - return rv < 0 ? rv : 0; + + return fasync_helper(inode, file, on, &fasync[port]); } #endif diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c index 537959d0714..bc8996c849a 100644 --- a/drivers/platform/x86/sony-laptop.c +++ b/drivers/platform/x86/sony-laptop.c @@ -1917,12 +1917,7 @@ static struct sonypi_compat_s sonypi_compat = { static int sonypi_misc_fasync(int fd, struct file *filp, int on) { - int retval; - - retval = fasync_helper(fd, filp, on, &sonypi_compat.fifo_async); - if (retval < 0) - return retval; - return 0; + return fasync_helper(fd, filp, on, &sonypi_compat.fifo_async); } static int sonypi_misc_release(struct inode *inode, struct file *file) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 516925d8b57..b4ef2f84ea3 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1154,7 +1154,6 @@ sg_poll(struct file *filp, poll_table * wait) static int sg_fasync(int fd, struct file *filp, int mode) { - int retval; Sg_device *sdp; Sg_fd *sfp; @@ -1163,8 +1162,7 @@ sg_fasync(int fd, struct file *filp, int mode) SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n", sdp->disk->disk_name, mode)); - retval = fasync_helper(fd, filp, mode, &sfp->async_qp); - return (retval < 0) ? retval : 0; + return fasync_helper(fd, filp, mode, &sfp->async_qp); } static int diff --git a/fs/fcntl.c b/fs/fcntl.c index 431bb645927..d865ca66ccb 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -184,6 +184,8 @@ static int setfl(int fd, struct file * filp, unsigned long arg) error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); if (error < 0) goto out; + if (error > 0) + error = 0; } spin_lock(&filp->f_lock); filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); diff --git a/fs/ioctl.c b/fs/ioctl.c index e8e89edba57..ac2d47e4392 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -432,7 +432,7 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp, else error = -ENOTTY; } - return error; + return error < 0 ? error : 0; } static int ioctl_fsfreeze(struct file *filp) diff --git a/fs/pipe.c b/fs/pipe.c index 14f502b89cf..94ad15967cf 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -667,10 +667,7 @@ pipe_read_fasync(int fd, struct file *filp, int on) retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers); mutex_unlock(&inode->i_mutex); - if (retval < 0) - return retval; - - return 0; + return retval; } @@ -684,10 +681,7 @@ pipe_write_fasync(int fd, struct file *filp, int on) retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers); mutex_unlock(&inode->i_mutex); - if (retval < 0) - return retval; - - return 0; + return retval; } @@ -706,11 +700,7 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on) fasync_helper(-1, filp, 0, &pipe->fasync_readers); } mutex_unlock(&inode->i_mutex); - - if (retval < 0) - return retval; - - return 0; + return retval; } diff --git a/sound/core/control.c b/sound/core/control.c index 636b3b52ef8..4b20fa2b7e6 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1373,12 +1373,9 @@ EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat); static int snd_ctl_fasync(int fd, struct file * file, int on) { struct snd_ctl_file *ctl; - int err; + ctl = file->private_data; - err = fasync_helper(fd, file, on, &ctl->fasync); - if (err < 0) - return err; - return 0; + return fasync_helper(fd, file, on, &ctl->fasync); } /* diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index a789efc9df3..a75c194e629 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3246,9 +3246,7 @@ static int snd_pcm_fasync(int fd, struct file * file, int on) err = fasync_helper(fd, file, on, &runtime->fasync); out: unlock_kernel(); - if (err < 0) - return err; - return 0; + return err; } /* diff --git a/sound/core/timer.c b/sound/core/timer.c index 796532081e8..3f0050d0b71 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -1825,13 +1825,9 @@ static long snd_timer_user_ioctl(struct file *file, unsigned int cmd, static int snd_timer_user_fasync(int fd, struct file * file, int on) { struct snd_timer_user *tu; - int err; tu = file->private_data; - err = fasync_helper(fd, file, on, &tu->fasync); - if (err < 0) - return err; - return 0; + return fasync_helper(fd, file, on, &tu->fasync); } static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,