Messages in this thread | | | Date | Thu, 13 Dec 2001 12:47:52 -0500 (EST) | From | Alexander Viro <> | Subject | Re: [RFC] Change locking in block_dev.c:do_open() |
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On Thu, 13 Dec 2001, Richard Gooch wrote:
> Al, I came up with a proposed solution for this race days ago. After > switching to try_inc_mod_count() (based on your first comments), you > haven't responded with whether you still see a problem with this > approach (your first message implied there were multiple problems).
Sigh... Please, take a look at sys_swapon() or get_sb_bdev() or devfs_open(). Any version starting with 2.3.46-pre<something> when devfs went into the tree.
All of them have ->bd_op set from devfs handle and follow that with blkdev_get() - directly or indirectly via def_blk_fops.open(). That function blocks. Think what will happen if entry is removed while blkdev_get() sleeps on semaphore.
BTW, I'd described that to you several times - last one couple of months ago on l-k.
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