block: push BKL into blktrace ioctls

The blktrace driver currently needs the BKL, but
we should not need to take that in the block layer,
so just push it down into the driver itself.

It is quite likely that the BKL is not actually
required in blktrace code and could be removed
in a follow-on patch.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index f26051f446814d24cf2bb1bb4077de455ffe54af..d530856377318a6bcc00bf732e1ffcb2a7e52498 100644 (file)
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -535,56 +535,6 @@ out:
        return err;
 }
 
-struct compat_blk_user_trace_setup {
-       char name[32];
-       u16 act_mask;
-       u32 buf_size;
-       u32 buf_nr;
-       compat_u64 start_lba;
-       compat_u64 end_lba;
-       u32 pid;
-};
-#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
-
-static int compat_blk_trace_setup(struct block_device *bdev, char __user *arg)
-{
-       struct blk_user_trace_setup buts;
-       struct compat_blk_user_trace_setup cbuts;
-       struct request_queue *q;
-       char b[BDEVNAME_SIZE];
-       int ret;
-
-       q = bdev_get_queue(bdev);
-       if (!q)
-               return -ENXIO;
-
-       if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
-               return -EFAULT;
-
-       bdevname(bdev, b);
-
-       buts = (struct blk_user_trace_setup) {
-               .act_mask = cbuts.act_mask,
-               .buf_size = cbuts.buf_size,
-               .buf_nr = cbuts.buf_nr,
-               .start_lba = cbuts.start_lba,
-               .end_lba = cbuts.end_lba,
-               .pid = cbuts.pid,
-       };
-       memcpy(&buts.name, &cbuts.name, 32);
-
-       mutex_lock(&bdev->bd_mutex);
-       ret = do_blk_trace_setup(q, b, bdev->bd_dev, bdev, &buts);
-       mutex_unlock(&bdev->bd_mutex);
-       if (ret)
-               return ret;
-
-       if (copy_to_user(arg, &buts.name, 32))
-               return -EFAULT;
-
-       return 0;
-}
-
 static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
                        unsigned cmd, unsigned long arg)
 {
@@ -802,16 +752,10 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
                return compat_put_u64(arg, bdev->bd_inode->i_size);
 
        case BLKTRACESETUP32:
-               lock_kernel();
-               ret = compat_blk_trace_setup(bdev, compat_ptr(arg));
-               unlock_kernel();
-               return ret;
        case BLKTRACESTART: /* compatible */
        case BLKTRACESTOP:  /* compatible */
        case BLKTRACETEARDOWN: /* compatible */
-               lock_kernel();
                ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
-               unlock_kernel();
                return ret;
        default:
                if (disk->fops->compat_ioctl)

diff --git a/block/ioctl.c b/block/ioctl.c
index 1cfa8d449d90d57e0c979093fedab181950a98ae..9d91e830b32095fd34b96b71275109ca2e7fd6c9 100644 (file)
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -320,9 +320,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
        case BLKTRACESTOP:
        case BLKTRACESETUP:
        case BLKTRACETEARDOWN:
-               lock_kernel();
                ret = blk_trace_ioctl(bdev, cmd, (char __user *) arg);
-               unlock_kernel();
                break;
        default:
                ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 23faa67e80223e0d221e95237e6ea3977bc368a0..07c698621ad097ddf7776744605810ce71c93deb 100644 (file)
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -5,6 +5,7 @@
 #ifdef __KERNEL__
 #include <linux/blkdev.h>
 #include <linux/relay.h>
+#include <linux/compat.h>
 #endif
 
 /*
@@ -203,6 +204,17 @@ extern int blk_trace_init_sysfs(struct device *dev);
 
 extern struct attribute_group blk_trace_attr_group;
 
+struct compat_blk_user_trace_setup {
+       char name[32];
+       u16 act_mask;
+       u32 buf_size;
+       u32 buf_nr;
+       compat_u64 start_lba;
+       compat_u64 end_lba;
+       u32 pid;
+};
+#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
+
 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 # define blk_trace_ioctl(bdev, cmd, arg)               (-ENOTTY)
 # define blk_trace_shutdown(q)                         do { } while (0)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 3b4a695051b603fa74cb4f33b37e0e032bbcac46..82499a5bdcb7c9779fc1c95840df41f424f18695 100644 (file)
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -552,6 +552,41 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 }
 EXPORT_SYMBOL_GPL(blk_trace_setup);
 
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+static int compat_blk_trace_setup(struct request_queue *q, char *name,
+                                 dev_t dev, struct block_device *bdev,
+                                 char __user *arg)
+{
+       struct blk_user_trace_setup buts;
+       struct compat_blk_user_trace_setup cbuts;
+       int ret;
+
+       if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
+               return -EFAULT;
+
+       buts = (struct blk_user_trace_setup) {
+               .act_mask = cbuts.act_mask,
+               .buf_size = cbuts.buf_size,
+               .buf_nr = cbuts.buf_nr,
+               .start_lba = cbuts.start_lba,
+               .end_lba = cbuts.end_lba,
+               .pid = cbuts.pid,
+       };
+       memcpy(&buts.name, &cbuts.name, 32);
+
+       ret = do_blk_trace_setup(q, name, dev, bdev, &buts);
+       if (ret)
+               return ret;
+
+       if (copy_to_user(arg, &buts.name, 32)) {
+               blk_trace_remove(q);
+               return -EFAULT;
+       }
+
+       return 0;
+}
+#endif
+
 int blk_trace_startstop(struct request_queue *q, int start)
 {
        int ret;
@@ -604,6 +639,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
        if (!q)
                return -ENXIO;
 
+       lock_kernel();
        mutex_lock(&bdev->bd_mutex);
 
        switch (cmd) {
@@ -611,6 +647,12 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
                bdevname(bdev, b);
                ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
                break;
+#if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
+       case BLKTRACESETUP32:
+               bdevname(bdev, b);
+               ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
+               break;
+#endif
        case BLKTRACESTART:
                start = 1;
        case BLKTRACESTOP:
@@ -625,6 +667,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
        }
 
        mutex_unlock(&bdev->bd_mutex);
+       unlock_kernel();
        return ret;
 }