Commit adb42f5e authored by Aruna Balakrishnaiah's avatar Aruna Balakrishnaiah Committed by Tony Luck
Browse files

pstore: Add decompression support to pstore 



Based on the flag 'compressed' set or not, pstore will decompress the
data returning a plain text file. If decompression fails for a particular
record it will have the compressed data in the file which can be
decompressed with 'openssl' command line tool.

Signed-off-by: default avatarAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 9a4e1398

fs/pstore/platform.c

+51 −2
Original line number Diff line number Diff line
@@ -162,6 +162,36 @@ error: 
	return ret;

}



/* Derived from logfs_uncompress */

static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)

{

	int err, ret;



	ret = -EIO;

	err = zlib_inflateInit(&stream);

	if (err != Z_OK)

		goto error;



	stream.next_in = in;

	stream.avail_in = inlen;

	stream.total_in = 0;

	stream.next_out = out;

	stream.avail_out = outlen;

	stream.total_out = 0;



	err = zlib_inflate(&stream, Z_FINISH);

	if (err != Z_STREAM_END)

		goto error;



	err = zlib_inflateEnd(&stream);

	if (err != Z_OK)

		goto error;



	ret = stream.total_out;

error:

	return ret;

}



static void allocate_buf_for_compression(void)

{

	size_t size;
@@ -429,6 +459,7 @@ void pstore_get_records(int quiet) 
	struct timespec		time;

	int			failed = 0, rc;

	bool			compressed;

	int			unzipped_len = -1;



	if (!psi)

		return;
@@ -439,10 +470,28 @@ void pstore_get_records(int quiet) 


	while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,

				psi)) > 0) {

		if (compressed && (type == PSTORE_TYPE_DMESG)) {

			if (big_oops_buf)

				unzipped_len = pstore_decompress(buf,

							big_oops_buf, size,

							big_oops_buf_sz);



			if (unzipped_len > 0) {

				buf = big_oops_buf;

				size = unzipped_len;

			} else {

				pr_err("pstore: decompression failed;"

					"returned %d\n", unzipped_len);

			}

		}

		rc = pstore_mkfile(type, psi->name, id, count, buf,

				  (size_t)size, time, psi);

		if (unzipped_len < 0) {

			/* Free buffer other than big oops */

			kfree(buf);

			buf = NULL;

		} else

			unzipped_len = -1;

		if (rc && (rc != -EEXIST || !quiet))

			failed++;

	}

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