Module Name: src
Committed By: riz
Date: Wed Jan 2 23:23:15 UTC 2013
Modified Files:
src/sys/kern [netbsd-6]: vfs_wapbl.c
Log Message:
Pull up following revision(s) (requested by hannken in ticket #758):
sys/kern/vfs_wapbl.c: revision 1.53
sys/kern/vfs_wapbl.c: revision 1.54
wapbl_biodone: Release the buffer before reclaiming the log.
wapbl_flush() may wait for the log to become empty and
all buffers should be unbusy before it returns.
Try to coalesce writes to the journal in MAXPHYS sized and aligned blocks.
Speeds up wapbl_flush() on raid5 by a factor of 3-4.
Discussed on tech-kern.
Needs pullup to NetBSD-6.
To generate a diff of this commit:
cvs rdiff -u -r1.51.2.1 -r1.51.2.2 src/sys/kern/vfs_wapbl.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_wapbl.c
diff -u src/sys/kern/vfs_wapbl.c:1.51.2.1 src/sys/kern/vfs_wapbl.c:1.51.2.2
--- src/sys/kern/vfs_wapbl.c:1.51.2.1 Mon May 7 03:01:13 2012
+++ src/sys/kern/vfs_wapbl.c Wed Jan 2 23:23:15 2013
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_wapbl.c,v 1.51.2.1 2012/05/07 03:01:13 riz Exp $ */
+/* $NetBSD: vfs_wapbl.c,v 1.51.2.2 2013/01/02 23:23:15 riz Exp $ */
/*-
* Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
#define WAPBL_INTERNAL
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.51.2.1 2012/05/07 03:01:13 riz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.51.2.2 2013/01/02 23:23:15 riz Exp $");
#include <sys/param.h>
#include <sys/bitops.h>
@@ -184,6 +184,10 @@ struct wapbl {
SIMPLEQ_HEAD(, wapbl_entry) wl_entries; /* On disk transaction
accounting */
+
+ u_char *wl_buffer; /* l: buffer for wapbl_buffered_write() */
+ daddr_t wl_buffer_dblk; /* l: buffer disk block address */
+ size_t wl_buffer_used; /* l: buffer current use */
};
#ifdef WAPBL_DEBUG_PRINT
@@ -489,6 +493,9 @@ wapbl_start(struct wapbl ** wlp, struct
wl->wl_dealloclens = wapbl_alloc(sizeof(*wl->wl_dealloclens) *
wl->wl_dealloclim);
+ wl->wl_buffer = wapbl_alloc(MAXPHYS);
+ wl->wl_buffer_used = 0;
+
wapbl_inodetrk_init(wl, WAPBL_INODETRK_SIZE);
/* Initialize the commit header */
@@ -537,6 +544,7 @@ wapbl_start(struct wapbl ** wlp, struct
sizeof(*wl->wl_deallocblks) * wl->wl_dealloclim);
wapbl_free(wl->wl_dealloclens,
sizeof(*wl->wl_dealloclens) * wl->wl_dealloclim);
+ wapbl_free(wl->wl_buffer, MAXPHYS);
wapbl_inodetrk_free(wl);
wapbl_free(wl, sizeof(*wl));
@@ -716,6 +724,7 @@ wapbl_stop(struct wapbl *wl, int force)
sizeof(*wl->wl_deallocblks) * wl->wl_dealloclim);
wapbl_free(wl->wl_dealloclens,
sizeof(*wl->wl_dealloclens) * wl->wl_dealloclim);
+ wapbl_free(wl->wl_buffer, MAXPHYS);
wapbl_inodetrk_free(wl);
cv_destroy(&wl->wl_reclaimable_cv);
@@ -791,6 +800,81 @@ wapbl_read(void *data, size_t len, struc
}
/*
+ * Flush buffered data if any.
+ */
+static int
+wapbl_buffered_flush(struct wapbl *wl)
+{
+ int error;
+
+ if (wl->wl_buffer_used == 0)
+ return 0;
+
+ error = wapbl_doio(wl->wl_buffer, wl->wl_buffer_used,
+ wl->wl_devvp, wl->wl_buffer_dblk, B_WRITE);
+ wl->wl_buffer_used = 0;
+
+ return error;
+}
+
+/*
+ * Write data to the log.
+ * Try to coalesce writes and emit MAXPHYS aligned blocks.
+ */
+static int
+wapbl_buffered_write(void *data, size_t len, struct wapbl *wl, daddr_t pbn)
+{
+ int error;
+ size_t resid;
+
+ /*
+ * If not adjacent to buffered data flush first. Disk block
+ * address is always valid for non-empty buffer.
+ */
+ if (wl->wl_buffer_used > 0 &&
+ pbn != wl->wl_buffer_dblk + btodb(wl->wl_buffer_used)) {
+ error = wapbl_buffered_flush(wl);
+ if (error)
+ return error;
+ }
+ /*
+ * If this write goes to an empty buffer we have to
+ * save the disk block address first.
+ */
+ if (wl->wl_buffer_used == 0)
+ wl->wl_buffer_dblk = pbn;
+ /*
+ * Remaining space so this buffer ends on a MAXPHYS boundary.
+ *
+ * Cannot become less or equal zero as the buffer would have been
+ * flushed on the last call then.
+ */
+ resid = MAXPHYS - dbtob(wl->wl_buffer_dblk % btodb(MAXPHYS)) -
+ wl->wl_buffer_used;
+ KASSERT(resid > 0);
+ KASSERT(dbtob(btodb(resid)) == resid);
+ if (len >= resid) {
+ memcpy(wl->wl_buffer + wl->wl_buffer_used, data, resid);
+ wl->wl_buffer_used += resid;
+ error = wapbl_doio(wl->wl_buffer, wl->wl_buffer_used,
+ wl->wl_devvp, wl->wl_buffer_dblk, B_WRITE);
+ data = (uint8_t *)data + resid;
+ len -= resid;
+ wl->wl_buffer_dblk = pbn + btodb(resid);
+ wl->wl_buffer_used = 0;
+ if (error)
+ return error;
+ }
+ KASSERT(len < MAXPHYS);
+ if (len > 0) {
+ memcpy(wl->wl_buffer + wl->wl_buffer_used, data, len);
+ wl->wl_buffer_used += len;
+ }
+
+ return 0;
+}
+
+/*
* Off is byte offset returns new offset for next write
* handles log wraparound
*/
@@ -813,7 +897,7 @@ wapbl_circ_write(struct wapbl *wl, void
#ifdef _KERNEL
pbn = btodb(pbn << wl->wl_log_dev_bshift);
#endif
- error = wapbl_write(data, slen, wl->wl_devvp, pbn);
+ error = wapbl_buffered_write(data, slen, wl, pbn);
if (error)
return error;
data = (uint8_t *)data + slen;
@@ -824,7 +908,7 @@ wapbl_circ_write(struct wapbl *wl, void
#ifdef _KERNEL
pbn = btodb(pbn << wl->wl_log_dev_bshift);
#endif
- error = wapbl_write(data, len, wl->wl_devvp, pbn);
+ error = wapbl_buffered_write(data, len, wl, pbn);
if (error)
return error;
off += len;
@@ -1224,6 +1308,9 @@ wapbl_biodone(struct buf *bp)
{
struct wapbl_entry *we = bp->b_private;
struct wapbl *wl = we->we_wapbl;
+#ifdef WAPBL_DEBUG_BUFBYTES
+ const int bufsize = bp->b_bufsize;
+#endif
/*
* Handle possible flushing of buffers after log has been
@@ -1233,8 +1320,8 @@ wapbl_biodone(struct buf *bp)
KASSERT(we->we_bufcount > 0);
we->we_bufcount--;
#ifdef WAPBL_DEBUG_BUFBYTES
- KASSERT(we->we_unsynced_bufbytes >= bp->b_bufsize);
- we->we_unsynced_bufbytes -= bp->b_bufsize;
+ KASSERT(we->we_unsynced_bufbytes >= bufsize);
+ we->we_unsynced_bufbytes -= bufsize;
#endif
if (we->we_bufcount == 0) {
@@ -1300,15 +1387,22 @@ wapbl_biodone(struct buf *bp)
#endif
}
+ /*
+ * Release the buffer here. wapbl_flush() may wait for the
+ * log to become empty and we better unbusy the buffer before
+ * wapbl_flush() returns.
+ */
+ brelse(bp, 0);
+
mutex_enter(&wl->wl_mtx);
KASSERT(we->we_bufcount > 0);
we->we_bufcount--;
#ifdef WAPBL_DEBUG_BUFBYTES
- KASSERT(we->we_unsynced_bufbytes >= bp->b_bufsize);
- we->we_unsynced_bufbytes -= bp->b_bufsize;
- KASSERT(wl->wl_unsynced_bufbytes >= bp->b_bufsize);
- wl->wl_unsynced_bufbytes -= bp->b_bufsize;
+ KASSERT(we->we_unsynced_bufbytes >= bufsize);
+ we->we_unsynced_bufbytes -= bufsize;
+ KASSERT(wl->wl_unsynced_bufbytes >= bufsize);
+ wl->wl_unsynced_bufbytes -= bufsize;
#endif
/*
@@ -1345,7 +1439,6 @@ wapbl_biodone(struct buf *bp)
}
mutex_exit(&wl->wl_mtx);
- brelse(bp, 0);
}
/*
@@ -1958,6 +2051,9 @@ wapbl_write_commit(struct wapbl *wl, off
int error;
daddr_t pbn;
+ error = wapbl_buffered_flush(wl);
+ if (error)
+ return error;
/*
* flush disk cache to ensure that blocks we've written are actually
* written to the stable storage before the commit header.
@@ -1989,7 +2085,10 @@ wapbl_write_commit(struct wapbl *wl, off
#ifdef _KERNEL
pbn = btodb(pbn << wc->wc_log_dev_bshift);
#endif
- error = wapbl_write(wc, wc->wc_len, wl->wl_devvp, pbn);
+ error = wapbl_buffered_write(wc, wc->wc_len, wl, pbn);
+ if (error)
+ return error;
+ error = wapbl_buffered_flush(wl);
if (error)
return error;
