On Thu, Sep 14, 2023 at 11:58:59AM +0200, Juergen Borleis wrote: > An Android sparse image file generated by the 'genimage' tool can be seen as a > kind of compression, since it contains only the data which should really be > written to a device. > > This implementation writes only the intended content and skips anything else. > > Signed-off-by: Juergen Borleis <[email protected]>
Tested-by: Uwe Kleine-König <[email protected]> while this obviously works, I still have a comment below: > --- > lib/uncompress.c | 82 +++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 78 insertions(+), 4 deletions(-) > > diff --git a/lib/uncompress.c b/lib/uncompress.c > index 0608e9f..f17e9ce 100644 > --- a/lib/uncompress.c > +++ b/lib/uncompress.c > @@ -25,6 +25,10 @@ > #include <malloc.h> > #include <fs.h> > #include <libfile.h> > +#ifdef CONFIG_IMAGE_SPARSE > +#include <image-sparse.h> > +#include <linux/sizes.h> > +#endif > > static void *uncompress_buf; > static unsigned int uncompress_size; > @@ -60,6 +64,71 @@ static int uncompress_fill(void *buf, unsigned int len) > return total; > } > > +#ifdef CONFIG_IMAGE_SPARSE > +static int uncompress_sparse(int source, int destination) > +{ > + int ret = 0; > + struct sparse_image_ctx *sparse; > + > + /* rewind after checking the file type */ > + lseek(source, 0, SEEK_SET); > + > + sparse = sparse_image_fd(source); > + if (IS_ERR(sparse)) { > + pr_err("Failed to open or interpret sparse image file: %m\n"); > + ret = 1; > + goto on_error_dev; > + } > + > + const size_t transfer_buffer_length = SZ_128K; > + unsigned char *buf = malloc(transfer_buffer_length); > + if (!buf) { > + pr_err("Failed to alloc memory for the transfers\n"); > + ret = 1; > + goto on_error_sparse; > + } > + > + while (1) { > + loff_t write_offset; > + size_t write_length; > + > + int rc = sparse_image_read(sparse, buf, &write_offset, > transfer_buffer_length, &write_length); > + if (rc) { > + ret = 1; > + goto on_error_memory; > + } > + if (!write_length) > + break; > + > + discard_range(destination, write_length, write_offset); > + > + write_offset = lseek(destination, write_offset, SEEK_SET); > + if (write_offset == -1) { > + pr_err("Failed to set next data's destination offset: > %m\n"); > + ret = 1; > + goto on_error_memory; > + > + } > + > + rc = write_full(destination, buf, write_length); > + if (rc < 0) { > + pr_err("Failed to write destination's next data: %m\n"); > + ret = 1; > + goto on_error_memory; > + } > + } > + > +on_error_memory: > + free(buf); > +on_error_sparse: > + free(sparse); /* Note: sparse_image_close(sparse); would also close the > input file descriptor */ > +on_error_dev: > + return ret; > +} > +#endif > + > +static int uncompress_infd, uncompress_outfd; > + > int uncompress(unsigned char *inbuf, int len, > int(*fill)(void*, unsigned int), > int(*flush)(void*, unsigned int), > @@ -121,6 +190,10 @@ int uncompress(unsigned char *inbuf, int len, > case filetype_xz_compressed: > compfn = decompress_unxz; > break; > +#endif > +#ifdef CONFIG_IMAGE_SPARSE > + case filetype_android_sparse: > + break; > #endif > default: > err = basprintf("cannot handle filetype %s", > @@ -131,16 +204,17 @@ int uncompress(unsigned char *inbuf, int len, > goto err; > } > > - ret = compfn(inbuf, len, fill ? uncompress_fill : NULL, > - flush, output, pos, error_fn); > + if (ft == filetype_android_sparse) > + ret = uncompress_sparse(uncompress_infd, uncompress_outfd); > + else > + ret = compfn(inbuf, len, fill ? uncompress_fill : NULL, > + flush, output, pos, error_fn); Wouldn't it be more natural to make uncompress_sparse use the same prototype as the other uncompress functions and then just have: #ifdef CONFIG_IMAGE_SPARSE case filetype_android_sparse: compfn = decompress_sparse; break; #endif Without the need to adapt the compfn call? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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