diff options
| -rw-r--r-- | fs/pstore/platform.c | 148 |
1 files changed, 139 insertions, 9 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 20fa686..56218cb 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -26,6 +26,7 @@ #include <linux/console.h> #include <linux/module.h> #include <linux/pstore.h> +#include <linux/zlib.h> #include <linux/string.h> #include <linux/timer.h> #include <linux/slab.h> @@ -65,6 +66,15 @@ struct pstore_info *psinfo; static char *backend; +/* Compression parameters */ +#define COMPR_LEVEL 6 +#define WINDOW_BITS 12 +#define MEM_LEVEL 4 +static struct z_stream_s stream; + +static char *big_oops_buf; +static size_t big_oops_buf_sz; + /* How much of the console log to snapshot */ static unsigned long kmsg_bytes = 10240; @@ -117,6 +127,91 @@ bool pstore_cannot_block_path(enum kmsg_dump_reason reason) } EXPORT_SYMBOL_GPL(pstore_cannot_block_path); +/* Derived from logfs_compress() */ +static int pstore_compress(const void *in, void *out, size_t inlen, + size_t outlen) +{ + int err, ret; + + ret = -EIO; + err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, + MEM_LEVEL, Z_DEFAULT_STRATEGY); + 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_deflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) + goto error; + + err = zlib_deflateEnd(&stream); + if (err != Z_OK) + goto error; + + if (stream.total_out >= stream.total_in) + goto error; + + ret = stream.total_out; +error: + return ret; +} + +static void allocate_buf_for_compression(void) +{ + size_t size; + + big_oops_buf_sz = (psinfo->bufsize * 100) / 45; + big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); + if (big_oops_buf) { + size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), + zlib_inflate_workspacesize()); + stream.workspace = kmalloc(size, GFP_KERNEL); + if (!stream.workspace) { + pr_err("pstore: No memory for compression workspace; " + "skipping compression\n"); + kfree(big_oops_buf); + big_oops_buf = NULL; + } + } else { + pr_err("No memory for uncompressed data; " + "skipping compression\n"); + stream.workspace = NULL; + } + +} + +/* + * Called when compression fails, since the printk buffer + * would be fetched for compression calling it again when + * compression fails would have moved the iterator of + * printk buffer which results in fetching old contents. + * Copy the recent messages from big_oops_buf to psinfo->buf + */ +static size_t copy_kmsg_to_buffer(int hsize, size_t len) +{ + size_t total_len; + size_t diff; + + total_len = hsize + len; + + if (total_len > psinfo->bufsize) { + diff = total_len - psinfo->bufsize + hsize; + memcpy(psinfo->buf, big_oops_buf, hsize); + memcpy(psinfo->buf + hsize, big_oops_buf + diff, + psinfo->bufsize - hsize); + total_len = psinfo->bufsize; + } else + memcpy(psinfo->buf, big_oops_buf, total_len); + + return total_len; +} + /* * callback from kmsg_dump. (s2,l2) has the most recently * written bytes, older bytes are in (s1,l1). Save as much @@ -148,23 +243,56 @@ static void pstore_dump(struct kmsg_dumper *dumper, char *dst; unsigned long size; int hsize; + int zipped_len = -1; size_t len; - bool compressed = false; + bool compressed; + size_t total_len; - dst = psinfo->buf; - hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part); - size = psinfo->bufsize - hsize; - dst += hsize; + if (big_oops_buf) { + dst = big_oops_buf; + hsize = sprintf(dst, "%s#%d Part%d\n", why, + oopscount, part); + size = big_oops_buf_sz - hsize; - if (!kmsg_dump_get_buffer(dumper, true, dst, size, &len)) - break; + if (!kmsg_dump_get_buffer(dumper, true, dst + hsize, + size, &len)) + break; + + zipped_len = pstore_compress(dst, psinfo->buf, + hsize + len, psinfo->bufsize); + + if (zipped_len > 0) { + compressed = true; + total_len = zipped_len; + } else { + pr_err("pstore: compression failed for Part %d" + " returned %d\n", part, zipped_len); + pr_err("pstore: Capture uncompressed" + " oops/panic report of Part %d\n", part); + compressed = false; + total_len = copy_kmsg_to_buffer(hsize, len); + } + } else { + dst = psinfo->buf; + hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, + part); + size = psinfo->bufsize - hsize; + dst += hsize; + + if (!kmsg_dump_get_buffer(dumper, true, dst, + size, &len)) + break; + + compressed = false; + total_len = hsize + len; + } ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, - oopscount, compressed, hsize + len, psinfo); + oopscount, compressed, total_len, psinfo); if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) pstore_new_entry = 1; - total += hsize + len; + total += total_len; part++; } if (pstore_cannot_block_path(reason)) { @@ -262,6 +390,8 @@ int pstore_register(struct pstore_info *psi) return -EINVAL; } + allocate_buf_for_compression(); + if (pstore_is_mounted()) pstore_get_records(0); |
