patch-2.4.2 linux/include/linux/raid/raid5.h
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- Lines: 41
- Date:
Thu Feb 8 19:38:38 2001
- Orig file:
v2.4.1/linux/include/linux/raid/raid5.h
- Orig date:
Fri Dec 29 14:07:24 2000
diff -u --recursive --new-file v2.4.1/linux/include/linux/raid/raid5.h linux/include/linux/raid/raid5.h
@@ -57,9 +57,9 @@
*
* Buffers for the md device that arrive via make_request are attached
* to the appropriate stripe in one of two lists linked on b_reqnext.
- * One list for read requests, one for write. There should never be
- * more than one buffer on the two lists together, but we are not
- * guaranteed of that so we allow for more.
+ * One list (bh_read) for read requests, one (bh_write) for write.
+ * There should never be more than one buffer on the two lists
+ * together, but we are not guaranteed of that so we allow for more.
*
* If a buffer is on the read list when the associated cache buffer is
* Uptodate, the data is copied into the read buffer and it's b_end_io
@@ -70,16 +70,18 @@
* that the Uptodate bit is set. Once they have checked that they may
* take buffers off the read queue.
*
- * When a buffer on the write_list is committed for write, it is
- * marked clean, copied into the cache buffer, which is then marked
- * dirty, and moved onto a third list, the written list. Once both
- * the parity block and the cached buffer are successfully written,
- * any buffer on a written list can be returned with b_end_io.
+ * When a buffer on the write list is committed for write is it copied
+ * into the cache buffer, which is then marked dirty, and moved onto a
+ * third list, the written list (bh_written). Once both the parity
+ * block and the cached buffer are successfully written, any buffer on
+ * a written list can be returned with b_end_io.
*
- * The write_list and read_list lists act as fifos. They are protected by the
- * device_lock which can be claimed when a stripe_lock is held.
- * The device_lock is only for list manipulations and will only be held for a very
- * short time. It can be claimed from interrupts.
+ * The write list and read list both act as fifos. The read list is
+ * protected by the device_lock. The write and written lists are
+ * protected by the stripe lock. The device_lock, which can be
+ * claimed while the stipe lock is held, is only for list
+ * manipulations and will only be held for a very short time. It can
+ * be claimed from interrupts.
*
*
* Stripes in the stripe cache can be on one of two lists (or on
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