off_t end;
};
+#define REGIONKEEP(r) ((r,beg == r.end)?: 0 : 1)
+
struct Source {
char *filename;
ssize_t from;
int dirty;
};
+#define ENDSOURCE( S ) ( S.start + ( S.to - S.from ) )
+
static struct {
struct Source *array;
int count;
/**
* 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();
#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();
}
+ // copy elements from [index] to [count-1] one element down
+ size_t size = ( sources.count - index - 1 ) * sizeof( struct Source );
+ memmove( &sources.array[ index+1 ], &sources.array[ index ], size );
}
#if DEBUG
perror( p->filename );
return 1; // Error return
}
- if ( ( range == 0 ) && stat( p->filename, &filestat ) ) {
+ if ( ( range != 0 ) && stat( p->filename, &filestat ) ) {
perror( p->filename );
return 1;
}
if ( offset >= sources.size ) {
return -1;
}
-#if DEBUG
- fprintf( stderr, "find_source( %ld )\n", offset );
-#endif
while ( lo + 1 < hi ) {
int m = ( lo + hi ) / 2;
if ( offset < sources.array[ m ].start ) {
-#if DEBUG
- fprintf( stderr, " offset < [%d].start: %ld\n",
- m, sources.array[ m ].start );
-#endif
hi = m;
} else {
-#if DEBUG
- fprintf( stderr, " offset >= [%d].start: %ld\n",
- m, sources.array[ m ].start );
-#endif
lo = m;
}
}
-#if DEBUG
- fprintf( stderr, "found %d\n", lo );
-#endif
return lo;
}
static int fusefile_read(const char *path, char *buf, size_t size,
off_t off, struct fuse_file_info *fi)
{
-#if DEBUG
- fprintf( stderr, "fusefile_read( %s )\n", path );
-#endif
if( strcmp( path, "/" ) != 0 ) {
return -ENOENT;
}
-#if DEBUG
- fprintf( stderr, "read %ld %ld\n", off, size );
-#endif
size_t rr = 0; // total reading
- while ( size > 0 ) {
#if DEBUG
- fprintf( stderr, " find_source %ld %ld\n", off, size );
+ fprintf( stderr, "fusefile_read %ld + %ld\n", off, size );
#endif
+ while ( size > 0 ) {
int i = find_source( off );
if ( i < 0 ) {
return ( off == sources.size )? rr : -ENOENT;
}
+#if DEBUG
+ fprintf( stderr, " item: %d ", i );
+ print_source(& sources.array[i] );
+#endif
if ( sources.array[i].fd < 0 ) {
return -ENOENT;
}
-#if DEBUG
- print_source( &sources.array[i] );
-#endif
times.atime = time( 0 );
size_t b = off - sources.array[i].start + sources.array[i].from;
size_t n = sources.array[i].to - b;
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
if ( lseek( sources.array[i].fd, b, SEEK_SET ) < 0 ) {
perror( sources.array[i].filename );
return -ENOENT;
}
-#if DEBUG
- fprintf( stderr, " now read %ld from fd=%d\n",
- n, sources.array[i].fd );
-#endif
ssize_t r = read( sources.array[i].fd, buf + rr, n );
#if DEBUG
- fprintf( stderr, " got %ld bytes\n", r );
+ fprintf( stderr, " got: %ld bytes of %ld at %ld\n", r, n, rr );
#endif
if ( r < 0 ) {
perror( sources.array[i].filename );
}
}
+/**
+ * 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, end },
+ { end, ENDSOURCE( sources.array[ index ] ) } };
+#if DEBUG
+ int i;
+ for ( i = 0; i < 3; i++ ) {
+ fprintf( stderr, "frags[%d] = (%ld, %ld)\n",
+ i, frags[i].beg, frags[i].end );
+ }
+#endif
+ ssize_t size = frags[0].end - frags[0].beg;
+ if ( size ) {
+ // Handle any portion before injection point.
+ dup_source_item( index );
+ off_t point = sources.array[ index ].from + size;
+ sources.array[ index ].to = point;
+#if DEBUG
+ fprintf( stderr, "item %d ", index );
+ print_source( &sources.array[ index ] );
+#endif
+ // Adjust item after injection point
+ index++;
+ sources.array[ index ].start = beg;
+ sources.array[ index ].from = point;
+#if DEBUG
+ fprintf( stderr, "item %d adjust ", index );
+ print_source( &sources.array[ index ] );
+#endif
+ }
+ size = frags[2].end - frags[2].beg;
+ if ( size ) {
+ // Handle any remaining portion following injection fragment
+ dup_source_item( index );
+ sources.array[ index+1 ].start = frags[2].beg;
+ sources.array[ index+1 ].from += frags[1].end - frags[1].beg;
+#if DEBUG
+ fprintf( stderr, "item %d ", index+1 );
+ print_source( &sources.array[ index+1 ] );
+#endif
+ }
+ // Set up the injection fragment
+ sources.array[ index ].filename = overlay.source.filename;
+ sources.array[ index ].from = beg;
+ sources.array[ index ].to = end;
+ sources.array[ index ].fd = overlay.source.fd;
+#if DEBUG
+ fprintf( stderr, "item %d ", index );
+ print_source( &sources.array[ index ] );
+#endif
+ 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 );
+ size_t n;
+ if ( ( n = read( overlay.source.fd, &count, size ) ) != size ) {
+ if ( n != 0 ) {
+ fprintf( stderr, "** error injecting %s\n",
+ overlay.source.filename );
+ usage();
+ }
+ fprintf( stderr, "** ignoring empty %s\n", overlay.source.filename );
+ }
+ 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 ) {
+#if DEBUG
+ fprintf( stderr, "inject [%ld,%ld] ", beg, overlay.table[i].end );
+ print_source( &overlay.source );
+#endif
+
+ beg = overlay_inject_from_region( beg, overlay.table[i].end );
+ }
+ }
+ free( overlay.table );
+ overlay.table = 0;
+}
+
+/**
+ * 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
*/
if ( strcmp( path, "/" ) != 0 ) {
return -ENOENT;
}
-
size_t size = 0;
int i;
for ( i = 0; i < buf->count; i++ ) {
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
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;
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 ].from,
+ 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,
+ sources.array[ src ].from +
+ pos - sources.array[ src ].start,
+ x - sources.array[ src ].start +
+ sources.array[ src ].from
+ );
+ }
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 &&
// note: (*argv)[ argc ] is the mount point argument
char *OURS[] = {
"-odefault_permissions",
+ //"-s", // Forced single-threading
(*argv)[ argc ]
};
#define OURSN ( sizeof( OURS ) / sizeof( char* ) )
}
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();
}
}
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 );
}
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 ) ) {