pstore: Add decompression support to pstore

[linux-2.6-block.git] / fs / pstore / platform.c

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 6418eb77d64bb5bae0e7d1349ddc3860fc1b71ea..76bc5c12c0cf76eb5e6e276305ce0bec2cc29282 100644 (file)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -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);
-               kfree(buf);
-               buf = NULL;
+               if (unzipped_len < 0) {
+                       /* Free buffer other than big oops */
+                       kfree(buf);
+                       buf = NULL;
+               } else
+                       unzipped_len = -1;
                if (rc && (rc != -EEXIST || !quiet))
                        failed++;
        }