From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Wed, 10 Aug 2022 10:58:29 +0000 (+1000)
Subject: bug fixing overlay option
X-Git-Tag: 0.5
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=c3822433d020325223dc098393e03131fd91330b;p=rrq%2Ffusefile.git

bug fixing overlay option
---

diff --git a/fusefile.c b/fusefile.c
index 99424c5..f74632a 100644
--- a/fusefile.c
+++ b/fusefile.c
@@ -45,6 +45,7 @@ struct Source {
     ssize_t to;
     ssize_t start; // starting position in concatenated file
     int fd;
+    int dirty;
 };
 
 static struct {
@@ -69,6 +70,8 @@ static struct {
     size_t limit;
 } overlay;
 
+static void usage();
+
 #define FRAG(m) (overlay.table+m)
 #define BEG(m) (FRAG(m)->pos)
 #define END(m) (FRAG(m)->pos + FRAG(m)->size)
@@ -102,6 +105,10 @@ static void overlay_save_count() {
 	size -= n;
 	p += n;
     }
+    if ( overlay.source.dirty++ > 1000 ) {
+	fsync( overlay.source.fd );
+	overlay.source.dirty = 0;
+    }
 }
 
 static void overlay_save_table(size_t lo,size_t hi) {
@@ -122,6 +129,10 @@ static void overlay_save_table(size_t lo,size_t hi) {
 	size -= n;
 	p += n;
     }
+    if ( overlay.source.dirty++ > 1000 ) {
+	fsync( overlay.source.fd );
+	overlay.source.dirty = 0;
+    }
 }
 
 static void overlay_insert(size_t p,off_t pos,size_t size) {
@@ -150,28 +161,77 @@ static void overlay_delete(size_t p) {
 }
 
 static void overlay_mark(off_t pos,size_t size) {
+#if DEBUG
+    fprintf( stderr, "overlay_mark( %ld, %ld )\n", pos, size );
+#endif
+    int deleted = 0;
+    ssize_t q;
     ssize_t p = overlay_prior_fragment( pos );
+    // p is the nearest region below pos (or -1)
     if ( p >= 0 && pos <= END(p) ) {
-	// Merge new marks with fragment p
+	// p overlaps mark region
+	if ( END(p) >= pos + size ) {
+#if DEBUG
+	fprintf( stderr, "overlay size 1( %ld )\n", FRAG(p)->size );
+#endif
+	    return; // new mark within existing.
+	}
+	// new mark region extends existing
 	FRAG(p)->size = pos + size - BEG(p);
-	if ( p+1 < overlay.count && BEG(p+1) <= END(p) ) {
-	    FRAG(p)->size = END(p+1) - BEG(p);
-	    overlay_delete( p+1 );
-	    overlay_save_table( p, overlay.count );
-	} else {
-	    overlay_save_table( p, p+1 );
+	q = p+1;
+	while ( q < overlay.count && BEG(q) <= END(p) ) {
+	    if ( END(q) > END(p) ) {
+		FRAG(p)->size = END(q) - BEG(p);
+	    }
+	    overlay_delete( q );
+	    deleted++;
 	}
+	overlay_save_table( p, deleted? overlay.count : q );
+#if DEBUG
+	fprintf( stderr, "overlay size 2( %ld ) deleted %d\n",
+		 FRAG(p)->size, deleted );
+#endif
 	return;
     }
-    p++; // index of subsequent fragment
-    if ( p < overlay.count && BEG(p) < pos + size ) {
-	// Merge new marks with pragment p+1
-	FRAG(p)->size = END(p) - pos;
-	FRAG(p)->pos = pos;
-	overlay_save_table( p, p+1 );
-    } else {
+    // The region p does not expand into new mark region
+    p++; // subsequent region
+    if ( p >= overlay.count || BEG(p) > pos + size ) {
+	// New mark is separate region at p
 	overlay_insert( p, pos, size);
+#if DEBUG
+	fprintf( stderr, "overlay size 4( %ld )\n", FRAG(p)->size );
+#endif
 	overlay_save_table( p, overlay.count );
+	return;
+    }
+    // New marks start before and overlap with the region
+    if ( BEG(p) + FRAG(p)->size < pos + size ) {
+	FRAG(p)->size = size; // new mark covers old region
+    } else {
+	FRAG(p)->size += BEG(p) - pos;
+    }
+    BEG(p) = pos;
+    q = p+1;
+    while ( q < overlay.count && BEG(q) <= END(p) ) {
+	if ( END(q) > END(p) ) {
+	    FRAG(p)->size = END(q) - BEG(p);
+	}
+	overlay_delete( q );
+	deleted++;
+    }
+    overlay_save_table( p, deleted? overlay.count : q );
+#if DEBUG
+    fprintf( stderr, "overlay size 4( %ld ) deleted %d\n",
+	     FRAG(p)->size, deleted );
+#endif
+}
+
+static void setup_overlay(char *filename) {
+    overlay.source.filename = filename;
+    overlay.source.fd = open( filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR );
+    if ( overlay.source.fd < 0 ) {
+	perror( filename );
+	usage();
     }
 }
 
@@ -188,17 +248,6 @@ static int RANGE(int s,int n ) {
     return ( s == n ) && *(range+c) == 0;
 }
 
-static void usage();
-
-static void setup_overlay(char *filename) {
-    overlay.source.filename = filename;
-    overlay.source.fd = open( filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR );
-    if ( overlay.source.fd < 0 ) {
-	perror( filename );
-	usage();
-    }
-}
-
 static int setup_sources(char **argv,int i,int n) {
     sources.array = calloc( n, sizeof( struct Source ) );
     if ( sources.array == 0 ) {
@@ -428,6 +477,10 @@ static int fusefile_read(const char *path, char *buf, size_t size,
 	if ( n > size ) {
 	    n = size;
 	}
+	if ( sources.array[i].dirty ) {
+	    fsync( sources.array[i].fd );
+	    sources.array[i].dirty = 0;
+	}
 #if DEBUG
 	fprintf( stderr, "  seek fd=%d to %ld\n", sources.array[i].fd, b );
 #endif
@@ -440,12 +493,6 @@ static int fusefile_read(const char *path, char *buf, size_t size,
 		 n, sources.array[i].fd );
 #endif
 	ssize_t r = read( sources.array[i].fd, buf + rr, n );
-	if ( overlay.source.filename ) {
-	    int x = overlay_merge( buf + rr, off + rr, r );
-	    if ( x ) {
-		return x;
-	    }
-	}
 #if DEBUG
 	fprintf( stderr, "  got %ld bytes\n", r );
 #endif
@@ -456,6 +503,16 @@ static int fusefile_read(const char *path, char *buf, size_t size,
 	if ( r == 0 ) {
 	    break;
 	}
+	if ( overlay.source.filename ) {
+	    if ( overlay.source.dirty ) {
+		fsync( overlay.source.fd );
+		overlay.source.dirty = 0;
+	    }
+	    int x = overlay_merge( buf + rr, off + rr, r );
+	    if ( x ) {
+		return x;
+	    }
+	}
 	rr += r;
 	off += r;
 	size -= r;
@@ -516,18 +573,16 @@ static int write_block(off_t off,const char *buf,size_t size) {
 #if DEBUG
     fprintf( stderr, "write_block( %ld, ?, %ld )\n", off, size );
 #endif
+    if ( overlay.source.filename ) {
+	overlay_mark( off, size ); // Mark region as written
+    }
     while ( size > 0 ) {
 	int index = find_source( off ); // index of source file
 	if ( index < 0 ) {
 	    return -EIO; // past EOF
 	}
-	struct Source *source;
-	if ( overlay.source.filename ) {
-	    source = &overlay.source;
-	    overlay_mark( off, size ); // Mark region as written
-	} else {
-	    source = &sources.array[ index ];
-	}
+	struct Source *source = overlay.source.filename?
+	    &overlay.source :  &sources.array[ index ];
 	off_t from = off - source->start + source->from;
 	off_t max = source->to - from;
 	if ( lseek( source->fd, from, SEEK_SET ) < 0 ) {
@@ -545,6 +600,10 @@ static int write_block(off_t off,const char *buf,size_t size) {
 	    size -= n;
 	    off += n;
 	}
+	if ( source->dirty++ >= 1000 ) {
+	    fsync( source->fd );
+	    source->dirty = 0;
+	}
     }
     return 0;
 }
@@ -608,6 +667,20 @@ static void fusefile_destroy(void *data) {
     }
 }
 
+static void fsync_all_dirty() {
+    int i = 0;
+    for ( ; i < sources.count; i++ ) {
+	if ( sources.array[i].dirty ) {
+	    fsync( sources.array[i].fd );
+	    sources.array[i].dirty = 0;
+	}
+    }
+    if ( overlay.source.filename && overlay.source.dirty ) {
+	fsync( overlay.source.fd );
+	overlay.source.dirty = 0;
+    }
+}
+
 static int fusefile_flush(const char *path, struct fuse_file_info *info) {
 #if DEBUG
     fprintf( stderr, "fusefile_flush( %s )\n", path );
@@ -615,6 +688,7 @@ static int fusefile_flush(const char *path, struct fuse_file_info *info) {
     if ( strcmp( path, "/" ) != 0 ) {
 	return -ENOENT;
     }
+    fsync_all_dirty();
     return 0;
 }
 
@@ -635,6 +709,7 @@ static int fusefile_fsync(const char *path, int x, struct fuse_file_info *fi) {
     if ( strcmp( path, "/" ) != 0 ) {
 	return -ENOENT;
     }
+    fsync_all_dirty();
     return 0;
 }