Messages in this thread Patch in this message |  | | Date | Mon, 08 Jan 2001 02:46:51 +0900 | From | HIBINO Kei <> | Subject | [PATCH] Atomic lock |
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I think atomic lock is needed for SMP code.
diff -ur linux-2.2.19pre6/drivers/block/ll_rw_blk.c linux-2.2.19pre6+lockfix/drivers/block/ll_rw_blk.c --- linux-2.2.19pre6/drivers/block/ll_rw_blk.c Mon Dec 11 09:49:41 2000 +++ linux-2.2.19pre6+lockfix/drivers/block/ll_rw_blk.c Mon Jan 8 02:40:37 2001 @@ -578,11 +578,9 @@ count = bh->b_size >> 9; sector = bh->b_rsector; - /* Uhhuh.. Nasty dead-lock possible here.. */ - if (buffer_locked(bh)) + if(test_and_set_bit(BH_Lock, &bh->b_state)) { /* Does atomic lock resolv problems? */ return; - /* Maybe the above fixes it, and maybe it doesn't boot. Life is interesting */ - lock_buffer(bh); + } if (blk_size[major]) { unsigned long maxsector = (blk_size[major][MINOR(bh->b_rdev)] << 1) + 1; diff -ur linux-2.2.19pre6/drivers/block/md.c linux-2.2.19pre6+lockfix/drivers/block/md.c --- linux-2.2.19pre6/drivers/block/md.c Tue Sep 5 02:39:16 2000 +++ linux-2.2.19pre6+lockfix/drivers/block/md.c Mon Jan 8 02:41:19 2001 @@ -778,9 +778,9 @@ int md_make_request (int minor, int rw, struct buffer_head * bh) { if (md_dev [minor].pers->make_request) { - if (buffer_locked(bh)) + if(test_and_set_bit(BH_Lock, &bh->b_state)) { /* atomic lock */ return 0; - set_bit(BH_Lock, &bh->b_state); + } if (rw == WRITE || rw == WRITEA) { if (!buffer_dirty(bh)) { bh->b_end_io(bh, test_bit(BH_Uptodate, &bh->b_state)); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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