Messages in this thread | | | Date | Wed, 8 May 2002 22:48:10 +0200 | From | Pavel Machek <> | Subject | Reading page from given block device |
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Hi!
For swsusp, I kind of need to read 4K from given block device.
Here's my attempt:
static int bdev_read_page(kdev_t dev, long pos, void *buf) { struct buffer_head *bh; struct block_device *bdev;
if (pos%PAGE_SIZE) panic("Sorry, dave, I can't let you do that!\n"); bdev = bdget(kdev_t_to_nr(dev)); if (!bdev) { printk("No block device for %s\n", __bdevname(dev)); BUG(); } printk("C"); bh = __bread(bdev, pos/PAGE_SIZE, PAGE_SIZE); printk("D"); bdput(bdev); if (!bh || (!bh->b_data)) { return -1; } memcpy(buf, bh->b_data, PAGE_SIZE); bforget(bh); /* FIXME: maybe bforget should be here */ return 0; }
It works *once*, second time it deadlocks in __bread(). I tried both bforget() and brelse(). Kernel is 2.5.13. What am I doing wrong/what's wrong?
Pavel -- (about SSSCA) "I don't say this lightly. However, I really think that the U.S. no longer is classifiable as a democracy, but rather as a plutocracy." --hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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