Merge branch 'master' into debian

diff --git a/debian/changelog b/debian/changelog
index f1aaad3ef9fa2c06d02c89c81a95bbc376e80ac4..9a43c81506a24a7be483406ad9431aaa968df11c 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,10 +1,12 @@
-fusefile (1.1-1) unstable; urgency=medium
+fusefile (1.2-1) unstable; urgency=medium
 
+  * Added stacked overlays
+  * Added -push action, to push overlay data into source fragments
   * Corrected fragment ranges to be 64-bit (long int)
   * Allow for fragment pathnames including "/" without range appendix
   * Fix index oob in -dump function.
 
- -- Ralph Ronnquist <rrq@rrq.au>  Thu, 03 Aug 2023 21:02:13 +1000
+ -- Ralph Ronnquist <rrq@rrq.au>  Tue, 15 Aug 2023 13:28:23 +1000
 
 fusefile (1.0-1) unstable; urgency=medium
 

diff --git a/fusefile.8 b/fusefile.8
index 6af36f49202ba1dc85f3e20690e54d8646ab0582..b952f5574075e2ae9b0df699ead855873618a772 100644 (file)
--- a/fusefile.8
+++ b/fusefile.8
@@ -8,6 +8,8 @@ fusefile, fusedisk \- FUSE file mount for combining file fragments
 .br
 .B fusefile \fB-dump\fR \fR[\fIfuse-opts\fR] \fBmountpoint\fR \fR[\fIoverlay\fR] \fIfilename/from-to\fR ...
 .br
+.B fusefile \fB-push\fR \fR[\fIfuse-opts\fR] \fBmountpoint\fR \fR[\fIoverlay\fR] \fIfilename/from-to\fR ...
+.br
 .B fusedisk \fR[\fIfuse-opts\fR] \fBmountpoint\fR \fR[\fIoverlay\fR] \fIfilename/from-to\fR ...
 
 .SH DESCRIPTION
@@ -31,14 +33,25 @@ any new written fused file regions followed by meta data to
 distinguish between new, written content and old content that comes
 from the fragments.
 
+By instead using the \fB-overlay:\fIlist\fR argument where \fIlist\fR
+is a colon-separated list of filenames, \fBfusefile\fR will use those
+as an ordered stack of overlays and "inject" them as fragments on top
+of each other.
+
 The option \fB-dump\fR as first argument together with a fusefile
 setup will print the setup to standard output rather than establishing
-a fusefile mount. This is of most use with a prior overlay setup,
-where then the printout includes the portions of updates that have
-been captured in the overlay. The printout is the series of fusefile
+a fusefile mount. This is of most use with a prior overlay setup where
+then the printout includes the portions of updates that have been
+captured in the overlay. The printout is the series of fusefile
 fragment argments to give in order to intersperse the captured overlay
 portions according to the overlay table.
 
+The option \fB-push\fR as first argument together with a fusefile
+setup will push the overlay into the sources (except for
+write-protected fragments). This is only of use with a prior overlay
+setup where then the updates that have been captured in the overlay
+get pushed into the fragments.
+
 \fBfusedisk\fR is a helper script to set up a \fBfusefile\fR as a
 block device (via \fIfuseblk\fR) by using the device mapper
 (\fBdmsetup\fR) to manage an empty block device mapping where content

diff --git a/fusefile.c b/fusefile.c
index 9e5cb45d835b771e73548b8b443461474fcaa487..ab97ff7f0f50c8902066075c2df1951f5c9fdb31 100644 (file)
--- a/fusefile.c
+++ b/fusefile.c
@@ -41,6 +41,8 @@ struct Region {
     off_t end;
 };
 
+#define REGIONKEEP(r) ((r,beg == r.end)?: 0 : 1)
+
 struct Source {
     char *filename;
     ssize_t from;
@@ -50,6 +52,8 @@ struct Source {
     int dirty;
 };
 
+#define ENDSOURCE( S ) ( S.start + ( S.to - S.from ) )
+
 static struct {
     struct Source *array;
     int count;
@@ -65,12 +69,12 @@ static struct {
 /**
  * Overlay
  */
-static struct {
+static struct Overlay {
     struct Source source;
     struct Region *table;
     size_t count;
     size_t limit;
-} overlay;
+} overlay; // The current overlay.
 
 static void usage();
 
@@ -270,13 +274,24 @@ static void overlay_mark(off_t beg,off_t end) {
 #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 );
+/**
+ * Capture overlay filenames for processing after source fragments.
+ */
+static void overlay_setup(char *filenames) {
+    overlay.source.filename = filenames;
+}
+
+// Duplicate the source record data at the given index.
+static void dup_source_item(int index) {
+    sources.count++;
+    sources.array = realloc(
+       sources.array, sources.count * sizeof( struct Source ) );
+    if ( sources.array == 0 ) {
+       fprintf( stderr, "** OOM when expanding frament table\n" );
        usage();
     }
+    memcpy( &sources.array[ index+1 ], &sources.array[ index ],
+           sizeof( struct Source ) );
 }
 
 #if DEBUG
@@ -626,6 +641,111 @@ static void overlay_load() {
     }
 }
 
+/**
+ * Inject an overlay fragment into the source table, end return the
+ * end of the injected fragment.
+ */
+static off_t overlay_inject_from_region(off_t beg,off_t end) {
+    int index = find_source( beg );
+    if ( index < 0 ) {
+       fprintf( stderr, "** Injecting %s at %ld failed\n",
+                overlay.source.filename, beg );
+       usage();
+    }
+    if ( end > ENDSOURCE( sources.array[ index ] ) ) {
+       end = ENDSOURCE( sources.array[ index ] );
+    }
+    struct Region frags[3] = {
+       { sources.array[ index ].start, beg },
+       { beg, ENDSOURCE( sources.array[ index ] ) },
+       { ENDSOURCE( sources.array[ index ] ), end } };
+    ssize_t size = frags[0].end - frags[0].beg;
+    if ( size ) {
+       // "Duplicate" the indexed source data, copying the filename
+       dup_source_item( index );
+       sources.array[ index ].to = sources.array[ index ].from + size;
+       index++;
+       sources.array[ index ].start = beg;
+       sources.array[ index ].from = sources.array[ index-1 ].to;
+    }
+    size = frags[2].end        - frags[2].beg;
+    if ( size ) {
+       dup_source_item( index );
+       sources.array[ index+1 ].start = frags[2].beg;
+       sources.array[ index+1 ].from = sources.array[ index+1 ].to -size;
+    }
+    // Replace the [index] fragment
+    sources.array[ index ].filename = overlay.source.filename;
+    sources.array[ index ].start = beg;
+    sources.array[ index ].from = beg;
+    sources.array[ index ].to = end;
+    sources.array[ index ].fd = overlay.source.fd; //?
+    return end;
+}
+
+/**
+ * Inject the current (unopened) overlay into the source list.
+ */
+static void overlay_inject() {
+    overlay.source.fd = open( overlay.source.filename, O_RDONLY );
+    if ( overlay.source.fd < 0 ) {
+       perror( overlay.source.filename );
+       usage();
+    }
+    
+    if ( lseek( overlay.source.fd, overlay.source.to, SEEK_SET ) < 0 ) {
+       perror( overlay.source.filename );
+       usage();
+    }
+    size_t count = 0;
+    size_t size = sizeof( overlay.count );
+    if ( read( overlay.source.fd, &count, size ) != size ) {
+       fprintf( stderr, "** error injecting %s\n", overlay.source.filename );
+       usage();
+    }
+    if ( count == 0 ) {
+       close( overlay.source.fd );
+       return;
+    }
+    size = count * sizeof( struct Region );
+    overlay.table = calloc( sizeof( struct Region ), count );
+    if ( read( overlay.source.fd, overlay.table, size ) != size ) {
+       fprintf( stderr, "** error injecting %s\n", overlay.source.filename );
+       usage();
+    }
+    size_t i;
+    for ( i = 0; i < count; i++ ) {
+       off_t beg = overlay.table[i].beg;
+       while ( beg < overlay.table[i].end ) {
+           beg = overlay_inject_from_region( beg, overlay.table[i].end );
+       }
+    }
+    free( overlay.table );
+    overlay.table = 0;
+    close( overlay.source.fd );
+}
+
+/**
+ * Each stacked overlay file is nested into to source list
+ */
+static void overlay_post_setup() {
+    char *end;
+    while ( ( end = strchr( overlay.source.filename, ':' ) ) ) {
+       *end = 0; //  
+       overlay_inject();
+       overlay.source.filename = end + 1;
+    }
+    if ( *overlay.source.filename ) {
+       overlay.source.fd = open( overlay.source.filename,
+                                 O_RDWR | O_CREAT, S_IRUSR | S_IWUSR );
+       if ( overlay.source.fd < 0 ) {
+           perror( overlay.source.filename );
+           usage();
+       }
+       overlay_load();
+    }
+}
+
 /**
  * Write a full block of data over the sources at the offset
  */
@@ -717,6 +837,40 @@ static int fusefile_write(const char *path, const char *buf, size_t size,
     return size;
 }
 
+#define PUSHBUF 104857600
+/**
+ * Write data from overlay to source.
+ */
+static void push_oly(off_t beg, off_t end) {
+    static char * buffer = 0;
+    // Pretend that there isn't an overlay
+    char *filename = overlay.source.filename;
+    if ( buffer == 0 ) {
+       buffer = malloc( PUSHBUF );
+       if ( buffer == 0 ) {
+           fprintf( stderr, "** OOM!!\n" );
+           exit( 1 );
+       }
+    }
+    overlay.source.filename = 0;
+    while ( beg < end ) {
+       off_t size = end - beg;
+       if ( size > PUSHBUF ) {
+           size = PUSHBUF;
+       }
+       if ( lseek( overlay.source.fd, beg, SEEK_SET ) < 0 ) {
+           fprintf( stderr, "** Cannot seek overlay at %ld\n", beg );
+           break;
+       }
+       size = read( overlay.source.fd, buffer, size );
+       if ( write_block( beg, buffer, size ) < 0 ) {
+           fprintf( stderr, "** Cannot push %ld bytes at %ld\n", size, beg );
+       }
+       beg += size;
+    }
+    overlay.source.filename = filename;
+}
+
 static void fusefile_destroy(void *data) {
     char *mnt = (char*) data; // As passed to fuse_main
 #if DEBUG
@@ -799,12 +953,10 @@ void *fusefile_init(struct fuse_conn_info *fci) {
     return 0;
 }
 
-#define ENDSOURCE( S ) ( S.start + ( S.to - S.from ) )
-
 /**
  * Dump the current fragmentation to stdout.
  */
-static int dump_fragments() {
+static int dump_fragments(int push) {
     int oly = 0;
     int src = 0;
     size_t pos = 0;
@@ -814,25 +966,33 @@ static int dump_fragments() {
        for ( ; src < sources.count && 
                  ENDSOURCE( sources.array[ src ] ) <= x; src++ ) {
            // Dump sources.array[src] in full
-           fprintf( stdout, "%s/%ld:%ld\n",
-                    sources.array[ src ].filename,
-                    pos - sources.array[ src ].start,
-                    sources.array[ src ].to );
+           if ( !push ) {
+               fprintf( stdout, "%s/%ld:%ld\n",
+                        sources.array[ src ].filename,
+                        pos - sources.array[ src ].start,
+                        sources.array[ src ].to );
+           }
            pos = ENDSOURCE( sources.array[ src ] );
        }
        if ( ( src < sources.count ) && ( sources.array[ src ].start < x ) ) {
            // Dump sources.array[src] up to x;
-           fprintf( stdout, "%s/%ld:%ld\n",
-                    sources.array[ src ].filename,
-                    pos - sources.array[ src ].start,
-                    x - sources.array[ src ].start );
+           if ( !push ) {
+               fprintf( stdout, "%s/%ld:%ld\n",
+                        sources.array[ src ].filename,
+                        pos - sources.array[ src ].start,
+                        x - sources.array[ src ].start );
+           }
            pos = ENDSOURCE( sources.array[ src ] );
        }
        if ( oly < overlay.count ) {
-           fprintf( stdout, "%s/%ld:%ld\n",
-                    overlay.source.filename,
-                    overlay.table[ oly ].beg,
-                    overlay.table[ oly ].end );
+           if ( !push ) {
+               fprintf( stdout, "%s/%ld:%ld\n",
+                        overlay.source.filename,
+                        overlay.table[ oly ].beg,
+                        overlay.table[ oly ].end );
+           } else {
+               push_oly( overlay.table[ oly ].beg, overlay.table[ oly ].end );
+           }
            pos = overlay.table[ oly++ ].end;
        }
        for ( ; src < sources.count &&
@@ -926,11 +1086,10 @@ int main(int argc, char *argv[])
     }
     fuseargc = i;
     mnt = argv[ i++ ]; // First non-option argument is the mount pount
-    char *overlaytag = "-overlay:";
-    int overlaytagsize = strlen( overlaytag );
-    if ( strncmp( argv[i], overlaytag, overlaytagsize ) == 0 ) {
-       // consume "-overlay:filename"
-       setup_overlay( argv[i++] + overlaytagsize ); // Need a writable file
+    #define OVERLAYTAG "-overlay:"
+    if ( strncmp( argv[i], OVERLAYTAG, strlen( OVERLAYTAG ) ) == 0 ) {
+       // consume "-overlay:filename[,filename]*"
+       overlay_setup( argv[i++] + strlen( OVERLAYTAG ) );
        if ( i >= argc ) {
            usage();
        }
@@ -940,7 +1099,7 @@ int main(int argc, char *argv[])
     }
     if ( overlay.source.filename ) {
        overlay.source.to = sources.size; // Register total size.
-       overlay_load();
+       overlay_post_setup();
     }
     if ( stat( mnt, &stbuf ) == -1 ) {
        int fd = open( mnt, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR );
@@ -975,7 +1134,10 @@ int main(int argc, char *argv[])
     }
     fuseargc = setup_argv( fuseargc, &argv );
     if ( strcmp( "-dump", argv[ 1 ] ) == 0 ) {
-       return dump_fragments();
+       return dump_fragments( 0 );
+    }
+    if ( strcmp( "-push", argv[ 1 ] ) == 0 ) {
+       return dump_fragments( 1 );
     }
     struct fuse_args args = FUSE_ARGS_INIT( fuseargc, argv );
     if ( fuse_parse_cmdline( &args, &mnt, &mt, &fg ) ) {