The patch titled
fasync: use f_lock to protect f_flags
has been removed from the -mm tree. Its filename was
fasync-use-f_lock-to-protect-f_flags.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: fasync: use f_lock to protect f_flags
From: Jonathan Corbet <corbet@xxxxxxx>
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.
Signed-off-by: Jonathan Corbet <corbet@xxxxxxx>
Acked-by: Matt Mackall <mpm@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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 -puN drivers/char/tty_io.c~fasync-use-f_lock-to-protect-f_flags drivers/char/tty_io.c
--- a/drivers/char/tty_io.c~fasync-use-f_lock-to-protect-f_flags
+++ a/drivers/char/tty_io.c
@@ -2162,13 +2162,12 @@ static int fionbio(struct file *file, in
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 -puN drivers/usb/gadget/file_storage.c~fasync-use-f_lock-to-protect-f_flags drivers/usb/gadget/file_storage.c
--- a/drivers/usb/gadget/file_storage.c~fasync-use-f_lock-to-protect-f_flags
+++ a/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 -puN fs/fcntl.c~fasync-use-f_lock-to-protect-f_flags fs/fcntl.c
--- a/fs/fcntl.c~fasync-use-f_lock-to-protect-f_flags
+++ a/fs/fcntl.c
@@ -189,7 +189,9 @@ static int setfl(int fd, struct file * f
}
}
+ 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 -puN fs/ioctl.c~fasync-use-f_lock-to-protect-f_flags fs/ioctl.c
--- a/fs/ioctl.c~fasync-use-f_lock-to-protect-f_flags
+++ a/fs/ioctl.c
@@ -404,10 +404,12 @@ static int ioctl_fionbio(struct file *fi
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 f
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, unsi
break;
case FIONBIO:
- /* BKL needed to avoid races tweaking f_flags */
- lock_kernel();
error = ioctl_fionbio(filp, argp);
- unlock_kernel();
break;
case FIOASYNC:
diff -puN fs/nfsd/vfs.c~fasync-use-f_lock-to-protect-f_flags fs/nfsd/vfs.c
--- a/fs/nfsd/vfs.c~fasync-use-f_lock-to-protect-f_flags
+++ a/fs/nfsd/vfs.c
@@ -998,8 +998,11 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s
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 -puN include/linux/fs.h~fasync-use-f_lock-to-protect-f_flags include/linux/fs.h
--- a/include/linux/fs.h~fasync-use-f_lock-to-protect-f_flags
+++ a/include/linux/fs.h
@@ -853,7 +853,7 @@ 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 -puN ipc/mqueue.c~fasync-use-f_lock-to-protect-f_flags ipc/mqueue.c
--- a/ipc/mqueue.c~fasync-use-f_lock-to-protect-f_flags
+++ a/ipc/mqueue.c
@@ -1156,10 +1156,12 @@ SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mq
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 -puN sound/core/oss/pcm_oss.c~fasync-use-f_lock-to-protect-f_flags sound/core/oss/pcm_oss.c
--- a/sound/core/oss/pcm_oss.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/core/oss/pcm_oss.c
@@ -1903,7 +1903,9 @@ static int snd_pcm_oss_set_fragment(stru
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 -puN sound/oss/au1550_ac97.c~fasync-use-f_lock-to-protect-f_flags sound/oss/au1550_ac97.c
--- a/sound/oss/au1550_ac97.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/oss/au1550_ac97.c
@@ -1627,7 +1627,9 @@ au1550_ioctl(struct inode *inode, struct
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 -puN sound/oss/audio.c~fasync-use-f_lock-to-protect-f_flags sound/oss/audio.c
--- a/sound/oss/audio.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/oss/audio.c
@@ -433,7 +433,9 @@ int audio_ioctl(int dev, struct file *fi
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 -puN sound/oss/sh_dac_audio.c~fasync-use-f_lock-to-protect-f_flags sound/oss/sh_dac_audio.c
--- a/sound/oss/sh_dac_audio.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/oss/sh_dac_audio.c
@@ -135,7 +135,9 @@ static int dac_audio_ioctl(struct inode
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 -puN sound/oss/swarm_cs4297a.c~fasync-use-f_lock-to-protect-f_flags sound/oss/swarm_cs4297a.c
--- a/sound/oss/swarm_cs4297a.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/oss/swarm_cs4297a.c
@@ -2200,7 +2200,9 @@ static int cs4297a_ioctl(struct inode *i
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 -puN sound/oss/vwsnd.c~fasync-use-f_lock-to-protect-f_flags sound/oss/vwsnd.c
--- a/sound/oss/vwsnd.c~fasync-use-f_lock-to-protect-f_flags
+++ a/sound/oss/vwsnd.c
@@ -2673,7 +2673,9 @@ static int vwsnd_audio_do_ioctl(struct i
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) */
_
Patches currently in -mm which might be from corbet@xxxxxxx are
linux-next.patch
pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash.patch
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