MFffs ffs_balloc.c 1.5.
Long ago, bread() set b_blkno to the disk block number as a side effect of doing physical i/o (or it just retained the setting from when the i/o was done). The setting is lost when buffers go away and then are reconsituted from VM. bread() originally compensated by doing a VOP_BMAP() to recover b_blkno, but this was no good since it sometimes caused extra i/o or even deadlock for bread()ing metadata to do the bmap. This was fixed in vfs_bio.c 1.33 (1995/03/03) and ffs_balloc.c 1.5, etc., by removing the VOP_BMAP() from bread() and breadn(), and changing all (?) places that used b_blkno to set it if necessary. ext2fs was not imported until later in 1995 and was still depending on the old behaviour of bread() in at least ext2_balloc(). This caused filesystem and file corruption by clobbering direct block numbers in inodes.
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svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=75951
@ -111,6 +111,7 @@ ext2_debug("ext2_balloc called (%d, %d, %d)\n",
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brelse(bp);
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return (error);
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}
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bp->b_blkno = fsbtodb(fs, nb);
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*bpp = bp;
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return (0);
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}
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@ -126,6 +127,7 @@ ext2_debug("ext2_balloc called (%d, %d, %d)\n",
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brelse(bp);
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return (error);
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}
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bp->b_blkno = fsbtodb(fs, nb);
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} else {
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/* Godmar thinks: this shouldn't happen w/o fragments */
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printf("nsize %d(%d) > osize %d(%d) nb %d\n",
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@ -111,6 +111,7 @@ ext2_debug("ext2_balloc called (%d, %d, %d)\n",
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brelse(bp);
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return (error);
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}
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bp->b_blkno = fsbtodb(fs, nb);
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*bpp = bp;
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return (0);
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}
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@ -126,6 +127,7 @@ ext2_debug("ext2_balloc called (%d, %d, %d)\n",
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brelse(bp);
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return (error);
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}
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bp->b_blkno = fsbtodb(fs, nb);
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} else {
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/* Godmar thinks: this shouldn't happen w/o fragments */
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printf("nsize %d(%d) > osize %d(%d) nb %d\n",
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