diff options
Diffstat (limited to 'fs/pstore/platform.c')
| -rw-r--r-- | fs/pstore/platform.c | 295 |
1 files changed, 263 insertions, 32 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 947fbe06c3b..0a9b72cdfec 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -18,6 +18,8 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#define pr_fmt(fmt) "pstore: " fmt + #include <linux/atomic.h> #include <linux/types.h> #include <linux/errno.h> @@ -26,6 +28,7 @@ #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 +68,15 @@ 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; @@ -96,6 +108,161 @@ static const char *get_reason_str(enum kmsg_dump_reason reason) } } +bool pstore_cannot_block_path(enum kmsg_dump_reason reason) +{ + /* + * In case of NMI path, pstore shouldn't be blocked + * regardless of reason. + */ + if (in_nmi()) + return true; + + switch (reason) { + /* In panic case, other cpus are stopped by smp_send_stop(). */ + case KMSG_DUMP_PANIC: + /* Emergency restart shouldn't be blocked by spin lock. */ + case KMSG_DUMP_EMERG: + return true; + default: + return false; + } +} +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; + } + +} + +/* + * 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 @@ -114,10 +281,12 @@ static void pstore_dump(struct kmsg_dumper *dumper, why = get_reason_str(reason); - if (in_nmi()) { - is_locked = spin_trylock(&psinfo->buf_lock); - if (!is_locked) - pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); + if (pstore_cannot_block_path(reason)) { + is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags); + if (!is_locked) { + pr_err("pstore dump routine blocked in %s path, may corrupt error record\n" + , in_nmi() ? "NMI" : why); + } } else spin_lock_irqsave(&psinfo->buf_lock, flags); oopscount++; @@ -125,27 +294,57 @@ static void pstore_dump(struct kmsg_dumper *dumper, 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) { + 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 { + 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, - 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 (in_nmi()) { + if (pstore_cannot_block_path(reason)) { if (is_locked) - spin_unlock(&psinfo->buf_lock); + spin_unlock_irqrestore(&psinfo->buf_lock, flags); } else spin_unlock_irqrestore(&psinfo->buf_lock, flags); } @@ -173,7 +372,7 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) spin_lock_irqsave(&psinfo->buf_lock, flags); } memcpy(psinfo->buf, s, c); - psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 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; @@ -197,10 +396,12 @@ static void pstore_register_console(void) {} static int pstore_write_compat(enum pstore_type_id type, enum kmsg_dump_reason reason, - u64 *id, unsigned int part, - size_t size, struct pstore_info *psi) + u64 *id, unsigned int part, int count, + 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); } /* @@ -216,17 +417,15 @@ 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; @@ -238,12 +437,17 @@ int pstore_register(struct pstore_info *psi) 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(); + + if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) { + pstore_register_console(); + pstore_register_ftrace(); + } if (pstore_update_ms >= 0) { pstore_timer.expires = jiffies + @@ -251,6 +455,8 @@ int pstore_register(struct pstore_info *psi) add_timer(&pstore_timer); } + pr_info("Registered %s as persistent store backend\n", psi->name); + return 0; } EXPORT_SYMBOL_GPL(pstore_register); @@ -267,9 +473,12 @@ void pstore_get_records(int quiet) char *buf = NULL; ssize_t size; u64 id; + int count; enum pstore_type_id type; struct timespec time; int failed = 0, rc; + bool compressed; + int unzipped_len = -1; if (!psi) return; @@ -278,11 +487,33 @@ void pstore_get_records(int quiet) if (psi->open && psi->open(psi)) goto out; - while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { - rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size, - time, psi); - kfree(buf); - buf = NULL; + 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, + 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++; } @@ -292,8 +523,8 @@ out: 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) |