summaryrefslogtreecommitdiffstats
path: root/fs/ocfs2/blockcheck.c
Commit message (Collapse)AuthorAgeFilesLines
* tree-wide: fix typos "offest" -> "offset"Uwe Kleine-König2009-12-041-1/+1
| | | | | | | | | This patch was generated by git grep -E -i -l 'offest' | xargs -r perl -p -i -e 's/offest/offset/' Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* ocfs2: Add statistics for the checksum and ecc operations.Joel Becker2009-06-031-8/+176
| | | | | | | | | | | | | It would be nice to know how often we get checksum failures. Even better, how many of them we can fix with the single bit ecc. So, we add a statistics structure. The structure can be installed into debugfs wherever the user wants. For ocfs2, we'll put it in the superblock-specific debugfs directory and pass it down from our higher-level functions. The stats are only registered with debugfs when the filesystem supports metadata ecc. Signed-off-by: Joel Becker <joel.becker@oracle.com>
* ocfs2: One more hamming code optimization.Joel Becker2009-01-051-42/+19
| | | | | | | | | | | | | | | The previous optimization used a fast find-highest-bit-set operation to give us a good starting point in calc_code_bit(). This version lets the caller cache the previous code buffer bit offset. Thus, the next call always starts where the last one left off. This reduces the calculation another 39%, for a total 80% reduction from the original, naive implementation. At least, on my machine. This also brings the parity calculation to within an order of magnitude of the crc32 calculation. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* ocfs2: Another hamming code optimization.Joel Becker2009-01-051-1/+39
| | | | | | | | | | | | | In the calc_code_bit() function, we must find all powers of two beneath the code bit number, *after* it's shifted by those powers of two. This requires a loop to see where it ends up. We can optimize it by starting at its most significant bit. This shaves 32% off the time, for a total of 67.6% shaved off of the original, naive implementation. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* ocfs2: Don't hand-code xor in ocfs2_hamming_encode().Joel Becker2009-01-051-47/+20
| | | | | | | | | | | | | | | | When I wrote ocfs2_hamming_encode(), I was following documentation of the algorithm and didn't have quite the (possibly still imperfect) grasp of it I do now. As part of this, I literally hand-coded xor. I would test a bit, and then add that bit via xor to the parity word. I can, of course, just do a single xor of the parity word and the source word (the code buffer bit offset). This cuts CPU usage by 53% on a mostly populated buffer (an inode containing utmp.h inline). Joel Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* ocfs2: block read meta ecc.Joel Becker2009-01-051-0/+9
| | | | | | | | | Add block check calls to the read_block validate functions. This is the almost all of the read-side checking of metaecc. xattr buckets are not checked yet. Writes are also unchecked, and so a read-write mount will quickly fail. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* ocfs2: Add the underlying blockcheck code.Joel Becker2009-01-051-0/+480
This is the code that computes crc32 and ecc for ocfs2 metadata blocks. There are high-level functions that check whether the filesystem has the ecc feature, mid-level functions that work on a single block or array of buffer_heads, and the low-level ecc hamming code that can handle multiple buffers like crc32_le(). It's not hooked up to the filesystem yet. Signed-off-by: Joel Becker <joel.becker@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
OpenPOWER on IntegriCloud