X-Git-Url: http://git.openafs.org/?p=openafs.git;a=blobdiff_plain;f=src%2Fdir%2Fbuffer.c;h=1a8da8f19698990262212a1d15c8b661458798a7;hp=5d00736bca4f6602d7bfb5d95a9714d26a2f5374;hb=70065cb1831dbcfd698c8fee216e33511a314904;hpb=a1b425f76746f9e56605eafd7c495ef21b84ad45

diff --git a/src/dir/buffer.c b/src/dir/buffer.c
index 5d00736..1a8da8f 100644
--- a/src/dir/buffer.c
+++ b/src/dir/buffer.c
@@ -1,7 +1,7 @@
 /*
  * Copyright 2000, International Business Machines Corporation and others.
  * All Rights Reserved.
- * 
+ *
  * This software has been released under the terms of the IBM Public
  * License.  For details, see the LICENSE file in the top-level source
  * directory or online at http://www.openafs.org/dl/license10.html
@@ -10,13 +10,40 @@
 #include <afsconfig.h>
 #include <afs/param.h>
 
-RCSID("$Header$");
+#include <roken.h>
+#include <afs/opr.h>
 
-#include <stdlib.h>
 #include <lock.h>
 
 #include "dir.h"
 
+#ifdef AFS_64BIT_IOPS_ENV
+#define BUFFER_FID_SIZE (9*sizeof(int) + 2*sizeof(char*))
+#else
+#define BUFFER_FID_SIZE (6*sizeof(int) + 2*sizeof(char*))
+#endif
+
+struct buffer {
+    /* fid is used for Unique cache key + i/o addressing.
+     * fid size is based on 4 + size of inode and size of pointer
+     */
+    char fid[BUFFER_FID_SIZE];
+    afs_int32 page;
+    afs_int32 accesstime;
+    struct buffer *hashNext;
+    void *data;
+    char lockers;
+    char dirty;
+    char hashIndex;
+    struct Lock lock;
+};
+
+static_inline dir_file_t
+bufferDir(struct buffer *b)
+{
+    return (dir_file_t) &b->fid;
+}
+
 struct Lock afs_bufferLock;
 
 /* page size */
@@ -30,7 +57,7 @@ struct Lock afs_bufferLock;
  * based on the volume id. This means this macro is dependent upon the
  * layout of DirHandle in viced/viced.h, vol/salvage.h and volser/salvage.h.
  */
-#define pHash(fid) ((fid)[0] & (PHSIZE-1))
+#define pHash(fid) (((afs_int32 *)fid)[0] & (PHSIZE-1))
 #define vHash(vid) (vid & (PHSIZE-1))
 
 /* admittedly system dependent, this is the maximum signed 32-bit value */
@@ -39,26 +66,7 @@ struct Lock afs_bufferLock;
 #define NULL 0
 #endif
 
-#ifdef AFS_64BIT_IOPS_ENV
-#define BUFFER_FID_SIZE (9 + 2*sizeof(char*)/sizeof(int))
-#else
-#define BUFFER_FID_SIZE (6 + 2*sizeof(char*)/sizeof(int))
-#endif
-
-struct buffer {
-    /* fid is used for Unique cache key + i/o addressing.
-     * fid size is based on 4 + size of inode and size of pointer
-     */
-    afs_int32 fid[BUFFER_FID_SIZE];
-    afs_int32 page;
-    afs_int32 accesstime;
-    struct buffer *hashNext;
-    char *data;
-    char lockers;
-    char dirty;
-    char hashIndex;
-    struct Lock lock;
-    } **Buffers;
+static struct buffer **Buffers;
 
 char *BufferData;
 
@@ -66,279 +74,333 @@ static struct buffer *phTable[PHSIZE];	/* page hash table */
 static struct buffer *LastBuffer;
 int nbuffers;
 int timecounter;
-static int calls=0, ios=0;
+static int calls = 0, ios = 0;
+
+struct buffer *newslot(dir_file_t dir, afs_int32 apage,
+		       struct buffer *lp);
+
+/* XXX - This sucks. The correct prototypes for these functions are ...
+ *
+ * extern void FidZero(DirHandle *);
+ * extern int  FidEq(DirHandle *a, DirHandle *b);
+ * extern int  ReallyRead(DirHandle *a, int block, char *data);
+ */
 
-struct buffer *newslot();
+extern void FidZero(dir_file_t);
+extern int FidEq(dir_file_t, dir_file_t);
+extern int ReallyRead(dir_file_t, int block, char *data);
+extern int ReallyWrite(dir_file_t, int block, char *data);
+extern void FidZap(dir_file_t);
+extern int  FidVolEq(dir_file_t, afs_int32 vid);
+extern void FidCpy(dir_file_t, dir_file_t fromfile);
 
-int DStat (abuffers, acalls, aios)
-    int *abuffers, *acalls, *aios;
-    {*abuffers = nbuffers;
+int
+DStat(int *abuffers, int *acalls, int *aios)
+{
+    *abuffers = nbuffers;
     *acalls = calls;
     *aios = ios;
-    }
+    return 0;
+}
 
-int DInit (abuffers)
-    int abuffers;
-    {/* Initialize the venus buffer system. */
-    register int i, tsize;
-    register struct buffer *tb;
-    register char *tp;
+/**
+ * initialize the directory package.
+ *
+ * @param[in] abuffers  size of directory buffer cache
+ *
+ * @return operation status
+ *    @retval 0 success
+ */
+void
+DInit(int abuffers)
+{
+    /* Initialize the venus buffer system. */
+    int i, tsize;
+    struct buffer *tb;
+    char *tp;
 
     Lock_Init(&afs_bufferLock);
     /* Align each element of Buffers on a doubleword boundary */
     tsize = (sizeof(struct buffer) + 7) & ~7;
-    tp = (char *) malloc(abuffers * tsize);
-    Buffers = (struct buffer **) malloc(abuffers * sizeof(struct buffer *));
-    BufferData = (char *) malloc(abuffers * BUFFER_PAGE_SIZE);
+    tp = malloc(abuffers * tsize);
+    Buffers = malloc(abuffers * sizeof(struct buffer *));
+    BufferData = malloc(abuffers * BUFFER_PAGE_SIZE);
     timecounter = 0;
     LastBuffer = (struct buffer *)tp;
     nbuffers = abuffers;
-    for(i=0;i<PHSIZE;i++) phTable[i] = 0;
-    for (i=0;i<abuffers;i++)
-        {/* Fill in each buffer with an empty indication. */
+    for (i = 0; i < PHSIZE; i++)
+	phTable[i] = 0;
+    for (i = 0; i < abuffers; i++) {
+	/* Fill in each buffer with an empty indication. */
 	tb = (struct buffer *)tp;
 	Buffers[i] = tb;
 	tp += tsize;
-        FidZero(tb->fid);
-        tb->accesstime = tb->lockers = 0;
-        tb->data = &BufferData[BUFFER_PAGE_SIZE*i];
+	FidZero(bufferDir(tb));
+	tb->accesstime = tb->lockers = 0;
+	tb->data = &BufferData[BUFFER_PAGE_SIZE * i];
 	tb->hashIndex = 0;
-        tb->dirty = 0;
+	tb->dirty = 0;
 	Lock_Init(&tb->lock);
-        }
-    return 0;
     }
+    return;
+}
+
+/**
+ * read a page out of a directory object.
+ *
+ * @param[in] fid   directory object fid
+ * @param[in] page  page in hash table to be read
+ *
+ * @return pointer to requested page in directory cache
+ *    @retval NULL read failed
+ */
+int
+DRead(dir_file_t fid, int page, struct DirBuffer *entry)
+{
+    /* Read a page from the disk. */
+    struct buffer *tb, *tb2, **bufhead;
 
-char *DRead(fid,page)
-  register afs_int32 *fid;
-  register int page;
-{ /* Read a page from the disk. */
-    register struct buffer *tb, *tb2, **bufhead;
+    memset(entry, 0, sizeof(struct DirBuffer));
 
     ObtainWriteLock(&afs_bufferLock);
     calls++;
 
-#define bufmatch(tb) (tb->page == page && FidEq(tb->fid, fid))
+#define bufmatch(tb,fid) (tb->page == page && FidEq(bufferDir(tb), fid))
 #define buf_Front(head,parent,p) {(parent)->hashNext = (p)->hashNext; (p)->hashNext= *(head);*(head)=(p);}
 
     /* this apparently-complicated-looking code is simply an example of
-     * a little bit of loop unrolling, and is a standard linked-list 
+     * a little bit of loop unrolling, and is a standard linked-list
      * traversal trick. It saves a few assignments at the the expense
      * of larger code size.  This could be simplified by better use of
      * macros.  With the use of these LRU queues, the old one-cache is
-     * probably obsolete. 
+     * probably obsolete.
      */
-    if ( tb = phTable[pHash(fid)] ) {  /* ASSMT HERE */
-	if (bufmatch(tb)) {
+    if ((tb = phTable[pHash(fid)])) {	/* ASSMT HERE */
+	if (bufmatch(tb, fid)) {
 	    ObtainWriteLock(&tb->lock);
-	    ReleaseWriteLock(&afs_bufferLock);
 	    tb->lockers++;
+	    ReleaseWriteLock(&afs_bufferLock);
 	    tb->accesstime = ++timecounter;
 	    ReleaseWriteLock(&tb->lock);
-	    return tb->data;
-	}
-	else {
-	  bufhead = &( phTable[pHash(fid)] );
-	  while (tb2 = tb->hashNext) {
-	    if (bufmatch(tb2)) {
-	      buf_Front(bufhead,tb,tb2);
-	      ObtainWriteLock(&tb2->lock);
-	      ReleaseWriteLock(&afs_bufferLock);
-	      tb2->lockers++;
-	      tb2->accesstime = ++timecounter;
-	      ReleaseWriteLock(&tb2->lock);
-	      return tb2->data;
-	    }
-	    if (tb = tb2->hashNext) { /* ASSIGNMENT HERE! */ 
-	      if (bufmatch(tb)) {
-		buf_Front(bufhead,tb2,tb);
-		ObtainWriteLock(&tb->lock);
-		ReleaseWriteLock(&afs_bufferLock);
-		tb->lockers++;
-		tb->accesstime = ++timecounter;
-		ReleaseWriteLock(&tb->lock);
-		return tb->data;
-	      }
+	    entry->buffer = tb;
+	    entry->data = tb->data;
+	    return 0;
+	} else {
+	    bufhead = &(phTable[pHash(fid)]);
+	    while ((tb2 = tb->hashNext)) {
+		if (bufmatch(tb2, fid)) {
+		    buf_Front(bufhead, tb, tb2);
+		    ObtainWriteLock(&tb2->lock);
+		    tb2->lockers++;
+		    ReleaseWriteLock(&afs_bufferLock);
+		    tb2->accesstime = ++timecounter;
+		    ReleaseWriteLock(&tb2->lock);
+		    entry->buffer = tb2;
+		    entry->data = tb2->data;
+		    return 0;
+		}
+		if ((tb = tb2->hashNext)) {	/* ASSIGNMENT HERE! */
+		    if (bufmatch(tb, fid)) {
+			buf_Front(bufhead, tb2, tb);
+			ObtainWriteLock(&tb->lock);
+			tb->lockers++;
+			ReleaseWriteLock(&afs_bufferLock);
+			tb->accesstime = ++timecounter;
+			ReleaseWriteLock(&tb->lock);
+			entry->buffer = tb;
+			entry->data = tb->data;
+			return 0;
+		    }
+		} else
+		    break;
 	    }
-	    else break;
-	  }
 	}
-      }  
-    else tb2 = NULL;
+    } else
+	tb2 = NULL;
 
     /* can't find it */
     /* The last thing we looked at was either tb or tb2 (or nothing). That
-     * is at least the oldest buffer on one particular hash chain, so it's 
+     * is at least the oldest buffer on one particular hash chain, so it's
      * a pretty good place to start looking for the truly oldest buffer.
      */
     tb = newslot(fid, page, (tb ? tb : tb2));
     ios++;
     ObtainWriteLock(&tb->lock);
-    ReleaseWriteLock(&afs_bufferLock);
     tb->lockers++;
-    if (ReallyRead(tb->fid,tb->page,tb->data)) {
+    ReleaseWriteLock(&afs_bufferLock);
+    if (ReallyRead(bufferDir(tb), tb->page, tb->data)) {
 	tb->lockers--;
-        FidZap(tb->fid);	/* disaster */
+	FidZap(bufferDir(tb));	/* disaster */
 	ReleaseWriteLock(&tb->lock);
-        return 0;
+	return EIO;
     }
     /* Note that findslot sets the page field in the buffer equal to
      * what it is searching for.
      */
     ReleaseWriteLock(&tb->lock);
-    return tb->data;
+    entry->buffer = tb;
+    entry->data = tb->data;
+    return 0;
 }
 
-static FixupBucket(ap)
-    register struct buffer *ap;
-    {register struct buffer **lp, *tp;
-    register int i;
+
+static int
+FixupBucket(struct buffer *ap)
+{
+    struct buffer **lp, *tp;
+    int i;
+
     /* first try to get it out of its current hash bucket, in which it might not be */
     i = ap->hashIndex;
     lp = &phTable[i];
-    for(tp = *lp; tp; tp=tp->hashNext)
-	{if (tp == ap)
-	    {*lp = tp->hashNext;
+    for (tp = *lp; tp; tp = tp->hashNext) {
+	if (tp == ap) {
+	    *lp = tp->hashNext;
 	    break;
-	    }
-	lp = &tp->hashNext;
 	}
+	lp = &tp->hashNext;
+    }
     /* now figure the new hash bucket */
-    i = pHash(ap->fid);
+    i = pHash(ap);
     ap->hashIndex = i;		/* remember where we are for deletion */
     ap->hashNext = phTable[i];	/* add us to the list */
-    phTable[i] = ap;            /* at the front, since it's LRU */
-    }
+    phTable[i] = ap;		/* at the front, since it's LRU */
+    return 0;
+}
 
-struct buffer *newslot (afid, apage, lp)
-    afs_int32 *afid, apage;
-     register struct buffer *lp;   /* pointer to a fairly-old buffer */
-    {/* Find a usable buffer slot */
-    register afs_int32 i;
-    afs_int32 lt,pt;
-    register struct buffer **tbp;
+struct buffer *
+newslot(dir_file_t dir, afs_int32 apage, struct buffer *lp)
+{
+    /* Find a usable buffer slot */
+    afs_int32 i;
+    afs_int32 lt;
+    struct buffer **tbp;
 
     if (lp && (lp->lockers == 0)) {
-      lt = lp->accesstime;
-    }
-    else {
-      lp = 0;
-      lt = BUFFER_LONG_MAX;
+	lt = lp->accesstime;
+    } else {
+	lp = 0;
+	lt = BUFFER_LONG_MAX;
     }
 
     tbp = Buffers;
-    for (i=0;i<nbuffers;i++,tbp++) {
-      if ((*tbp)->lockers == 0) {
-	if ((*tbp)->accesstime < lt) {
-	  lp = (*tbp);
-	  lt = (*tbp)->accesstime;
+    for (i = 0; i < nbuffers; i++, tbp++) {
+	if ((*tbp)->lockers == 0) {
+	    if ((*tbp)->accesstime < lt) {
+		lp = (*tbp);
+		lt = (*tbp)->accesstime;
+	    }
 	}
-      }
     }
 
     /* There are no unlocked buffers */
     if (lp == 0) {
-      if (lt < 0)
-	Die("accesstime counter wrapped");
-      else 
-	Die ("all buffers locked");
+	if (lt < 0)
+	    Die("accesstime counter wrapped");
+	else
+	    Die("all buffers locked");
     }
 
     /* We do not need to lock the buffer here because it has no lockers
      * and the afs_bufferLock prevents other threads from zapping this
      * buffer while we are writing it out */
     if (lp->dirty) {
-        if (ReallyWrite(lp->fid,lp->page,lp->data)) Die("writing bogus buffer");
-        lp->dirty = 0;
-        }
+	if (ReallyWrite(bufferDir(lp), lp->page, lp->data))
+	    Die("writing bogus buffer");
+	lp->dirty = 0;
+    }
 
     /* Now fill in the header. */
-    FidZap(lp->fid);
-    FidCpy(lp->fid, afid);	/* set this */
+    FidZap(bufferDir(lp));
+    FidCpy(bufferDir(lp), dir);	/* set this */
+    memset(lp->data, 0, BUFFER_PAGE_SIZE);  /* Don't leak stale data. */
     lp->page = apage;
     lp->accesstime = ++timecounter;
 
     FixupBucket(lp);		/* move to the right hash bucket */
 
     return lp;
-    }
+}
 
-DRelease (bp,flag)
-    register struct buffer *bp;
-    int flag;
-    {/* Release a buffer, specifying whether or not the buffer has been modified by the locker. */
-    register int index;
+/* Release a buffer, specifying whether or not the buffer has been modified
+ * by the locker. */
+void
+DRelease(struct DirBuffer *entry, int flag)
+{
+    struct buffer *bp;
 
-    if (!bp) return;
-    index = (((char *)bp)-((char *)BufferData))>>LOGPS;
-    bp = Buffers[index];
+    bp = (struct buffer *) entry->buffer;
+    if (bp == NULL)
+	return;
     ObtainWriteLock(&bp->lock);
     bp->lockers--;
-    if (flag) bp->dirty=1;
+    if (flag)
+	bp->dirty = 1;
     ReleaseWriteLock(&bp->lock);
-    }
+}
 
-DVOffset (ap)
-    register void *ap;
-    {/* Return the byte within a file represented by a buffer pointer. */
-    register struct buffer *bp;
-    register int index;
-    bp=ap;
-    index = (((char *)bp) - ((char *)BufferData)) >> LOGPS;
-    if (index<0 || index >= nbuffers) return -1;
-    bp = Buffers[index];
-    return BUFFER_PAGE_SIZE*bp->page+((char *)ap)-bp->data;
-    }
+/* Return the byte within a file represented by a buffer pointer. */
+int
+DVOffset(struct DirBuffer *entry)
+{
+    struct buffer *bp;
+
+    bp = entry->buffer;
+    return BUFFER_PAGE_SIZE * bp->page + (char *)entry->data - (char *)bp->data;
+}
 
-DZap (fid)
-    register afs_int32 *fid;
-    {/* Destroy all buffers pertaining to a particular fid. */
-    register struct buffer *tb;
+void
+DZap(dir_file_t dir)
+{
+    /* Destroy all buffers pertaining to a particular fid. */
+    struct buffer *tb;
     ObtainReadLock(&afs_bufferLock);
-    for(tb=phTable[pHash(fid)]; tb; tb=tb->hashNext)
-        if (FidEq(tb->fid,fid)) {
+    for (tb = phTable[pHash(dir)]; tb; tb = tb->hashNext)
+	if (FidEq(bufferDir(tb), dir)) {
 	    ObtainWriteLock(&tb->lock);
-	    FidZap(tb->fid);
+	    FidZap(bufferDir(tb));
 	    tb->dirty = 0;
 	    ReleaseWriteLock(&tb->lock);
 	}
     ReleaseReadLock(&afs_bufferLock);
-    }
+}
 
-DFlushVolume (vid)
-    register afs_int32 vid;
-    {/* Flush all data and release all inode handles for a particular volume */
-    register struct buffer *tb;
-    register int code, rcode = 0;
+int
+DFlushVolume(afs_int32 vid)
+{
+    /* Flush all data and release all inode handles for a particular volume */
+    struct buffer *tb;
+    int code, rcode = 0;
     ObtainReadLock(&afs_bufferLock);
-    for(tb=phTable[vHash(vid)]; tb; tb=tb->hashNext)
-        if (FidVolEq(tb->fid,vid)) {
+    for (tb = phTable[vHash(vid)]; tb; tb = tb->hashNext)
+	if (FidVolEq(bufferDir(tb), vid)) {
 	    ObtainWriteLock(&tb->lock);
 	    if (tb->dirty) {
-		code = ReallyWrite(tb->fid, tb->page, tb->data);
+		code = ReallyWrite(bufferDir(tb), tb->page, tb->data);
 		if (code && !rcode)
 		    rcode = code;
 		tb->dirty = 0;
 	    }
-	    FidZap(tb->fid);
+	    FidZap(bufferDir(tb));
 	    ReleaseWriteLock(&tb->lock);
 	}
     ReleaseReadLock(&afs_bufferLock);
     return rcode;
-    }
+}
 
-DFlushEntry (fid)
-register afs_int32 *fid;
-{/* Flush pages modified by one entry. */
-    register struct buffer *tb;
+int
+DFlushEntry(dir_file_t fid)
+{
+    /* Flush pages modified by one entry. */
+    struct buffer *tb;
     int code;
 
     ObtainReadLock(&afs_bufferLock);
-    for(tb = phTable[pHash(fid)]; tb; tb=tb->hashNext)
-        if (FidEq(tb->fid, fid) && tb->dirty) {
+    for (tb = phTable[pHash(fid)]; tb; tb = tb->hashNext)
+	if (FidEq(bufferDir(tb), fid) && tb->dirty) {
 	    ObtainWriteLock(&tb->lock);
 	    if (tb->dirty) {
-		code = ReallyWrite(tb->fid, tb->page, tb->data);
+		code = ReallyWrite(bufferDir(tb), tb->page, tb->data);
 		if (code) {
 		    ReleaseWriteLock(&tb->lock);
 		    ReleaseReadLock(&afs_bufferLock);
@@ -352,22 +414,24 @@ register afs_int32 *fid;
     return 0;
 }
 
-DFlush ()
-{/* Flush all the modified buffers. */
-    register int i;
-    register struct buffer **tbp;
+int
+DFlush(void)
+{
+    /* Flush all the modified buffers. */
+    int i;
+    struct buffer **tbp;
     afs_int32 code, rcode;
 
     rcode = 0;
     tbp = Buffers;
     ObtainReadLock(&afs_bufferLock);
-    for(i=0;i<nbuffers;i++,tbp++) {
-        if ((*tbp)->dirty) {
+    for (i = 0; i < nbuffers; i++, tbp++) {
+	if ((*tbp)->dirty) {
 	    ObtainWriteLock(&(*tbp)->lock);
 	    (*tbp)->lockers++;
 	    ReleaseReadLock(&afs_bufferLock);
 	    if ((*tbp)->dirty) {
-		code = ReallyWrite((*tbp)->fid, (*tbp)->page, (*tbp)->data);
+		code = ReallyWrite(bufferDir(*tbp), (*tbp)->page, (*tbp)->data);
 		if (!code)
 		    (*tbp)->dirty = 0;	/* Clear the dirty flag */
 		if (code && !rcode) {
@@ -383,22 +447,28 @@ DFlush ()
     return rcode;
 }
 
-char *DNew (fid,page)
-  register int page;
-  register afs_int32 *fid;
+/* Same as read, only do *not* even try to read the page,
+ * since it probably doesn't exist.
+ */
+int
+DNew(dir_file_t dir, int page, struct DirBuffer *entry)
 {
-    /* Same as read, only do *not* even try to read the page,
-     * since it probably doesn't exist.
-     */
-    register struct buffer *tb;
+    struct buffer *tb;
+
+    memset(entry,0, sizeof(struct DirBuffer));
+
     ObtainWriteLock(&afs_bufferLock);
-    if ((tb = newslot(fid,page,0)) == 0) {
+    if ((tb = newslot(dir, page, 0)) == 0) {
 	ReleaseWriteLock(&afs_bufferLock);
-	return 0;
+	return EIO;
     }
     ObtainWriteLock(&tb->lock);
-    ReleaseWriteLock(&afs_bufferLock);
     tb->lockers++;
+    ReleaseWriteLock(&afs_bufferLock);
     ReleaseWriteLock(&tb->lock);
-    return tb->data;
+
+    entry->buffer = tb;
+    entry->data = tb->data;
+
+    return 0;
 }