--- zzzz-none-000/linux-3.10.107/fs/pstore/platform.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/fs/pstore/platform.c 2021-02-04 17:41:59.000000000 +0000 @@ -18,6 +18,8 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#define pr_fmt(fmt) "pstore: " fmt + #include #include #include @@ -26,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -65,6 +68,15 @@ 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 +129,148 @@ } 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; +} + +/* 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_inflateInit2(&stream, WINDOW_BITS); + 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; + size_t cmpr; + + switch (psinfo->bufsize) { + /* buffer range for efivars */ + case 1000 ... 2000: + cmpr = 56; + break; + case 2001 ... 3000: + cmpr = 54; + break; + case 3001 ... 3999: + cmpr = 52; + break; + /* buffer range for nvram, erst */ + case 4000 ... 10000: + cmpr = 45; + break; + default: + cmpr = 60; + break; + } + + big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr; + 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("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; + } + +} + +static void free_buf_for_compression(void) +{ + kfree(stream.workspace); + stream.workspace = NULL; + kfree(big_oops_buf); + big_oops_buf = 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 @@ -148,22 +302,52 @@ char *dst; unsigned long size; int hsize; + int zipped_len = -1; size_t len; + 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 && is_locked) { + dst = big_oops_buf; + hsize = sprintf(dst, "%s#%d Part%u\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 { + compressed = false; + total_len = copy_kmsg_to_buffer(hsize, len); + } + } else { + dst = psinfo->buf; + hsize = sprintf(dst, "%s#%d Part%u\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, 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)) { @@ -177,6 +361,19 @@ .dump = pstore_dump, }; +/* + * Register with kmsg_dump to save last part of console log on panic. + */ +static void pstore_register_kmsg(void) +{ + kmsg_dump_register(&pstore_dumper); +} + +static void pstore_unregister_kmsg(void) +{ + kmsg_dump_unregister(&pstore_dumper); +} + #ifdef CONFIG_PSTORE_CONSOLE static void pstore_console_write(struct console *con, const char *s, unsigned c) { @@ -196,7 +393,7 @@ spin_lock_irqsave(&psinfo->buf_lock, flags); } memcpy(psinfo->buf, s, c); - psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, c, psinfo); + psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo); spin_unlock_irqrestore(&psinfo->buf_lock, flags); s += c; c = e - s; @@ -214,16 +411,24 @@ { register_console(&pstore_console); } + +static void pstore_unregister_console(void) +{ + unregister_console(&pstore_console); +} #else static void pstore_register_console(void) {} +static void pstore_unregister_console(void) {} #endif static int pstore_write_compat(enum pstore_type_id type, enum kmsg_dump_reason reason, u64 *id, unsigned int part, int count, - size_t size, struct pstore_info *psi) + bool compressed, size_t size, + struct pstore_info *psi) { - return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi); + return psi->write_buf(type, reason, id, part, psinfo->buf, compressed, + size, psi); } /* @@ -232,24 +437,20 @@ * read function right away to populate the file system. If not * then the pstore mount code will call us later to fill out * the file system. - * - * Register with kmsg_dump to save last part of console log on panic. */ int pstore_register(struct pstore_info *psi) { struct module *owner = psi->owner; + if (backend && strcmp(backend, psi->name)) + return -EPERM; + spin_lock(&pstore_lock); if (psinfo) { spin_unlock(&pstore_lock); return -EBUSY; } - if (backend && strcmp(backend, psi->name)) { - spin_unlock(&pstore_lock); - return -EINVAL; - } - if (!psi->write) psi->write = pstore_write_compat; psinfo = psi; @@ -261,12 +462,18 @@ return -EINVAL; } + allocate_buf_for_compression(); + if (pstore_is_mounted()) pstore_get_records(0); - kmsg_dump_register(&pstore_dumper); - pstore_register_console(); - pstore_register_ftrace(); + pstore_register_kmsg(); + + if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) { + pstore_register_console(); + pstore_register_ftrace(); + pstore_register_pmsg(); + } if (pstore_update_ms >= 0) { pstore_timer.expires = jiffies + @@ -274,10 +481,34 @@ add_timer(&pstore_timer); } + /* + * Update the module parameter backend, so it is visible + * through /sys/module/pstore/parameters/backend + */ + backend = psi->name; + + module_put(owner); + + pr_info("Registered %s as persistent store backend\n", psi->name); + return 0; } EXPORT_SYMBOL_GPL(pstore_register); +void pstore_unregister(struct pstore_info *psi) +{ + pstore_unregister_pmsg(); + pstore_unregister_ftrace(); + pstore_unregister_console(); + pstore_unregister_kmsg(); + + free_buf_for_compression(); + + psinfo = NULL; + backend = NULL; +} +EXPORT_SYMBOL_GPL(pstore_unregister); + /* * Read all the records from the persistent store. Create * files in our filesystem. Don't warn about -EEXIST errors @@ -294,6 +525,8 @@ enum pstore_type_id type; struct timespec time; int failed = 0, rc; + bool compressed; + int unzipped_len = -1; if (!psi) return; @@ -302,11 +535,33 @@ if (psi->open && psi->open(psi)) goto out; - while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) { + 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) { + kfree(buf); + buf = big_oops_buf; + size = unzipped_len; + compressed = false; + } else { + pr_err("decompression failed;returned %d\n", + unzipped_len); + compressed = true; + } + } rc = pstore_mkfile(type, psi->name, id, count, buf, - (size_t)size, time, psi); - kfree(buf); - buf = NULL; + compressed, (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++; } @@ -316,8 +571,8 @@ mutex_unlock(&psi->read_mutex); if (failed) - printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n", - failed, psi->name); + pr_warn("failed to load %d record(s) from '%s'\n", + failed, psi->name); } static void pstore_dowork(struct work_struct *work)