Messages in this thread Patch in this message |  | | From | Bjorn Helgaas <> | Subject | [PATCH] don't swapon mounted devices | Date | Wed, 5 Feb 2003 13:08:14 -0700 |
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The attached patch against 2.4.21-pre3 fixes a problem in sys_swapon. Previous behavior:
* boot kernel with "root=/dev/sda3 init=/bin/bash" (ext3 root) * mount -t proc proc /proc * /sbin/swapon /dev/sda3 <--- NOTE: same as root! * mount -n -o remount,rw / * oops in __make_request because superblock buffer_head is no longer mapped (via sys_swapon -> set_blocksize -> kill_bdev-> truncate_inode_pages -> do_flushpage -> block_flushpage -> discard_bh_page -> discard_buffer)
I think 2.5 avoids this problem by attempting to get exclusive use of the device with bd_claim (see http://linux.bkbits.net:8080/linux-2.5/cset@1.369.32.10?nav=index.html|src/.|src/mm|related/mm/swapfile.c)
bd_claim is not in 2.4, so this seems next-best.
Bjorn
--- 1.25/mm/swapfile.c Sat Dec 28 16:18:13 2002 +++ edited/mm/swapfile.c Wed Feb 5 10:32:27 2003 @@ -915,6 +915,11 @@ struct block_device_operations *bdops; devfs_handle_t de; + if (is_mounted(dev)) { + error = -EBUSY; + goto bad_swap_2; + } + p->swap_device = dev; set_blocksize(dev, PAGE_SIZE); - 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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