ubik: Abstract buffer matching and pass trans ptrs

Abstract the code for matching buffers in DRead, and pass around
ubik_trans pointers instead of ubik_dbase pointers. This changes no
behavior, but makes changing ubik buffer code a bit easier.

Change-Id: Ie98005edb0f0dc008190e709dc08d2cc5ef5e16c
Reviewed-on: http://gerrit.openafs.org/2230
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/ubik/disk.c b/src/ubik/disk.c
index 9a9da8f..00ba518 100644 (file)
--- a/src/ubik/disk.c
+++ b/src/ubik/disk.c
@@ -59,7 +59,7 @@ static struct buffer *newslot(struct ubik_dbase *adbase, afs_int32 afid,
 static int initd = 0;
 #define        BADFID      0xffffffff
 
-static int DTrunc(struct ubik_dbase *dbase, afs_int32 fid, afs_int32 length);
+static int DTrunc(struct ubik_trans *atrans, afs_int32 fid, afs_int32 length);
 
 static struct ubik_trunc *freeTruncList = 0;
 
@@ -316,28 +316,44 @@ Dmru(struct buffer *abuf)
     LruBuffer->lru_prev = abuf;
 }
 
+static_inline int
+MatchBuffer(struct buffer *buf, int page, afs_int32 fid,
+            struct ubik_trans *atrans)
+{
+    if (buf->page != page) {
+       return 0;
+    }
+    if (buf->file != fid) {
+       return 0;
+    }
+    if (buf->dbase != atrans->dbase) {
+       return 0;
+    }
+    return 1;
+}
+
 /*!
  * \brief Get a pointer to a particular buffer.
  */
 static char *
-DRead(struct ubik_dbase *dbase, afs_int32 fid, int page)
+DRead(struct ubik_trans *atrans, afs_int32 fid, int page)
 {
     /* Read a page from the disk. */
     struct buffer *tb, *lastbuffer;
     afs_int32 code;
+    struct ubik_dbase *dbase = atrans->dbase;
 
     calls++;
     lastbuffer = LruBuffer->lru_prev;
 
-    if ((lastbuffer->page == page) && (lastbuffer->file == fid)
-       && (lastbuffer->dbase == dbase)) {
+    if (MatchBuffer(lastbuffer, page, fid, atrans)) {
        tb = lastbuffer;
        tb->lockers++;
        lastb++;
        return tb->data;
     }
     for (tb = phTable[pHash(page)]; tb; tb = tb->hashNext) {
-       if (tb->page == page && tb->file == fid && tb->dbase == dbase) {
+       if (MatchBuffer(tb, page, fid, atrans)) {
            Dmru(tb);
            tb->lockers++;
            return tb->data;
@@ -372,11 +388,12 @@ DRead(struct ubik_dbase *dbase, afs_int32 fid, int page)
  * \brief Zap truncated pages.
  */
 static int
-DTrunc(struct ubik_dbase *dbase, afs_int32 fid, afs_int32 length)
+DTrunc(struct ubik_trans *atrans, afs_int32 fid, afs_int32 length)
 {
     afs_int32 maxPage;
     struct buffer *tb;
     int i;
+    struct ubik_dbase *dbase = atrans->dbase;
 
     maxPage = (length + UBIK_PAGESIZE - 1) >> UBIK_LOGPAGESIZE;        /* first invalid page now in file */
     for (i = 0, tb = Buffers; i < nbuffers; i++, tb++) {
@@ -447,7 +464,7 @@ DoTruncs(struct ubik_trans *atrans)
     tproc = atrans->dbase->truncate;
     for (tt = atrans->activeTruncs; tt; tt = nt) {
        nt = tt->next;
-       DTrunc(atrans->dbase, tt->file, tt->length);    /* zap pages from buffer cache */
+       DTrunc(atrans, tt->file, tt->length);   /* zap pages from buffer cache */
        code = (*tproc) (atrans->dbase, tt->file, tt->length);
        if (code)
            rcode = code;
@@ -566,11 +583,12 @@ DRelease(char *ap, int flag)
  * always call DFlush/DSync as a pair.
  */
 static int
-DFlush(struct ubik_dbase *adbase)
+DFlush(struct ubik_trans *atrans)
 {
     int i;
     afs_int32 code;
     struct buffer *tb;
+    struct ubik_dbase *adbase = atrans->dbase;
 
     tb = Buffers;
     for (i = 0; i < nbuffers; i++, tb++) {
@@ -590,7 +608,7 @@ DFlush(struct ubik_dbase *adbase)
  * \brief Flush all modified buffers.
  */
 static int
-DAbort(struct ubik_dbase *adbase)
+DAbort(struct ubik_trans *atrans)
 {
     int i;
     struct buffer *tb;
@@ -610,13 +628,14 @@ DAbort(struct ubik_dbase *adbase)
  * \attention DSync() must only be called after DFlush(), due to its interpretation of dirty flag.
  */
 static int
-DSync(struct ubik_dbase *adbase)
+DSync(struct ubik_trans *atrans)
 {
     int i;
     afs_int32 code;
     struct buffer *tb;
     afs_int32 file;
     afs_int32 rCode;
+    struct ubik_dbase *adbase = atrans->dbase;
 
     rCode = 0;
     while (1) {
@@ -643,9 +662,10 @@ DSync(struct ubik_dbase *adbase)
  * \brief Same as DRead(), only do not even try to read the page.
  */
 static char *
-DNew(struct ubik_dbase *dbase, afs_int32 fid, int page)
+DNew(struct ubik_trans *atrans, afs_int32 fid, int page)
 {
     struct buffer *tb;
+    struct ubik_dbase *dbase = atrans->dbase;
 
     if ((tb = newslot(dbase, fid, page)) == 0)
        return NULL;
@@ -663,14 +683,12 @@ udisk_read(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
 {
     char *bp;
     afs_int32 offset, len, totalLen;
-    struct ubik_dbase *dbase;
 
     if (atrans->flags & TRDONE)
        return UDONE;
     totalLen = 0;
-    dbase = atrans->dbase;
     while (alen > 0) {
-       bp = DRead(dbase, afile, apos >> UBIK_LOGPAGESIZE);
+       bp = DRead(atrans, afile, apos >> UBIK_LOGPAGESIZE);
        if (!bp)
            return UEOF;
        /* otherwise, min of remaining bytes and end of buffer to user mode */
@@ -731,7 +749,6 @@ udisk_write(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
 {
     char *bp;
     afs_int32 offset, len, totalLen;
-    struct ubik_dbase *dbase;
     struct ubik_trunc *tt;
     afs_int32 code;
 
@@ -740,9 +757,8 @@ udisk_write(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
     if (atrans->type != UBIK_WRITETRANS)
        return UBADTYPE;
 
-    dbase = atrans->dbase;
     /* first write the data to the log */
-    code = udisk_LogWriteData(dbase, afile, abuffer, apos, alen);
+    code = udisk_LogWriteData(atrans->dbase, afile, abuffer, apos, alen);
     if (code)
        return code;
 
@@ -757,9 +773,9 @@ udisk_write(struct ubik_trans *atrans, afs_int32 afile, void *abuffer,
     /* now update vm */
     totalLen = 0;
     while (alen > 0) {
-       bp = DRead(dbase, afile, apos >> UBIK_LOGPAGESIZE);
+       bp = DRead(atrans, afile, apos >> UBIK_LOGPAGESIZE);
        if (!bp) {
-           bp = DNew(dbase, afile, apos >> UBIK_LOGPAGESIZE);
+           bp = DNew(atrans, afile, apos >> UBIK_LOGPAGESIZE);
            if (!bp)
                return UIOERROR;
            memset(bp, 0, UBIK_PAGESIZE);
@@ -867,10 +883,10 @@ udisk_commit(struct ubik_trans *atrans)
        /* If we fail anytime after this, then panic and let the
         * recovery replay the log.
         */
-       code = DFlush(dbase);   /* write dirty pages to respective files */
+       code = DFlush(atrans);  /* write dirty pages to respective files */
        if (code)
            panic("Writing Ubik DB modifications\n");
-       code = DSync(dbase);    /* sync the files and mark pages not dirty */
+       code = DSync(atrans);   /* sync the files and mark pages not dirty */
        if (code)
            panic("Synchronizing Ubik DB modifications\n");
 
@@ -921,7 +937,7 @@ udisk_abort(struct ubik_trans *atrans)
        code = (*dbase->truncate) (dbase, LOGFILE, 0);
        if (code)
            panic("Truncating Ubik logfile during an abort\n");
-       DAbort(dbase);          /* remove all dirty pages */
+       DAbort(atrans);         /* remove all dirty pages */
     }
 
     /* When the transaction is marked done, it also means the logfile