From: Ralph Ronnquist <rrq@rrq.au>
Date: Fri, 11 Aug 2023 22:42:36 +0000 (+1000)
Subject: Added -push action, to push overlay data into source fragments.
X-Git-Tag: p-1.1.1~6^2
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=refs%2Fheads%2Fwip%2Fpush;p=rrq%2Ffusefile.git
Added -push action, to push overlay data into source fragments.
---
diff --git a/fusefile.8 b/fusefile.8
index 6af36f4..194f4aa 100644
--- 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
@@ -33,12 +35,18 @@ from the fragments.
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 9e5cb45..69750fa 100644
--- a/fusefile.c
+++ b/fusefile.c
@@ -717,6 +717,40 @@ 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
@@ -804,7 +838,7 @@ void *fusefile_init(struct fuse_conn_info *fci) {
/**
* 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 +848,33 @@ 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 &&
@@ -975,7 +1017,10 @@ 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 ) ) {