efi_pstore: Add a sequence counter to a variable name

[Issue]

Currently, a variable name, which identifies each entry, consists of type, id and ctime.
But if multiple events happens in a short time, a second/third event may fail to log because
efi_pstore can't distinguish each event with current variable name.

[Solution]

A reasonable way to identify all events precisely is introducing a sequence counter to
the variable name.

The sequence counter has already supported in a pstore layer with "oopscount".
So, this patch adds it to a variable name.
Also, it is passed to read/erase callbacks of platform drivers in accordance with
the modification of the variable name.

  <before applying this patch>
 a variable name of first event: dump-type0-1-12345678
 a variable name of second event: dump-type0-1-12345678

  type:0
  id:1
  ctime:12345678

 If multiple events happen in a short time, efi_pstore can't distinguish them because
 variable names are same among them.

  <after applying this patch>

 it can be distinguishable by adding a sequence counter as follows.

 a variable name of first event: dump-type0-1-1-12345678
 a variable name of Second event: dump-type0-1-2-12345678

  type:0
  id:1
  sequence counter: 1(first event), 2(second event)
  ctime:12345678

In case of a write callback executed in pstore_console_write(), "0" is added to
an argument of the write callback because it just logs all kernel messages and
doesn't need to care about multiple events.

Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 0bd6ae4a899fbdf1aa21b6ca7165ce4a76e19b7e..6d894bfd8b8fe8d7aa8f22642a42aa26ce9a68eb 100644 (file)
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -931,13 +931,13 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
 
 static int erst_open_pstore(struct pstore_info *psi);
 static int erst_close_pstore(struct pstore_info *psi);
-static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
                           struct timespec *time, char **buf,
                           struct pstore_info *psi);
 static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
-                      u64 *id, unsigned int part,
+                      u64 *id, unsigned int part, int count,
                       size_t size, struct pstore_info *psi);
-static int erst_clearer(enum pstore_type_id type, u64 id,
+static int erst_clearer(enum pstore_type_id type, u64 id, int count,
                        struct timespec time, struct pstore_info *psi);
 
 static struct pstore_info erst_info = {
@@ -987,7 +987,7 @@ static int erst_close_pstore(struct pstore_info *psi)
        return 0;
 }
 
-static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
                           struct timespec *time, char **buf,
                           struct pstore_info *psi)
 {
@@ -1055,7 +1055,7 @@ out:
 }
 
 static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
-                      u64 *id, unsigned int part,
+                      u64 *id, unsigned int part, int count,
                       size_t size, struct pstore_info *psi)
 {
        struct cper_pstore_record *rcd = (struct cper_pstore_record *)
@@ -1101,7 +1101,7 @@ static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
        return ret;
 }
 
-static int erst_clearer(enum pstore_type_id type, u64 id,
+static int erst_clearer(enum pstore_type_id type, u64 id, int count,
                        struct timespec time, struct pstore_info *psi)
 {
        return erst_clear(id);

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 3803621c0d45f6235897ed860870d14f47217247..7ad3aae6e0854e39f8194a7bd43bfe6db098677d 100644 (file)
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -658,13 +658,14 @@ static int efi_pstore_close(struct pstore_info *psi)
 }
 
 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
-                              struct timespec *timespec,
+                              int *count, struct timespec *timespec,
                               char **buf, struct pstore_info *psi)
 {
        efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
        struct efivars *efivars = psi->data;
        char name[DUMP_NAME_LEN];
        int i;
+       int cnt;
        unsigned int part, size;
        unsigned long time;
 
@@ -674,8 +675,10 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
                        for (i = 0; i < DUMP_NAME_LEN; i++) {
                                name[i] = efivars->walk_entry->var.VariableName[i];
                        }
-                       if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
+                       if (sscanf(name, "dump-type%u-%u-%d-%lu",
+                                  type, &part, &cnt, &time) == 4) {
                                *id = part;
+                               *count = cnt;
                                timespec->tv_sec = time;
                                timespec->tv_nsec = 0;
                                get_var_data_locked(efivars, &efivars->walk_entry->var);
@@ -698,7 +701,8 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 
 static int efi_pstore_write(enum pstore_type_id type,
                enum kmsg_dump_reason reason, u64 *id,
-               unsigned int part, size_t size, struct pstore_info *psi)
+               unsigned int part, int count, size_t size,
+               struct pstore_info *psi)
 {
        char name[DUMP_NAME_LEN];
        efi_char16_t efi_name[DUMP_NAME_LEN];
@@ -725,7 +729,7 @@ static int efi_pstore_write(enum pstore_type_id type,
                return -ENOSPC;
        }
 
-       sprintf(name, "dump-type%u-%u-%lu", type, part,
+       sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
                get_seconds());
 
        for (i = 0; i < DUMP_NAME_LEN; i++)
@@ -746,7 +750,7 @@ static int efi_pstore_write(enum pstore_type_id type,
        return ret;
 };
 
-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
                            struct timespec time, struct pstore_info *psi)
 {
        char name[DUMP_NAME_LEN];
@@ -756,7 +760,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id,
        struct efivar_entry *entry, *found = NULL;
        int i;
 
-       sprintf(name, "dump-type%u-%u-%lu", type, (unsigned int)id,
+       sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
                time.tv_sec);
 
        spin_lock(&efivars->lock);
@@ -807,7 +811,7 @@ static int efi_pstore_close(struct pstore_info *psi)
        return 0;
 }
 
-static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,
                               struct timespec *timespec,
                               char **buf, struct pstore_info *psi)
 {
@@ -816,12 +820,13 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 
 static int efi_pstore_write(enum pstore_type_id type,
                enum kmsg_dump_reason reason, u64 *id,
-               unsigned int part, size_t size, struct pstore_info *psi)
+               unsigned int part, int count, size_t size,
+               struct pstore_info *psi)
 {
        return 0;
 }
 
-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
                            struct timespec time, struct pstore_info *psi)
 {
        return 0;

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 4300af6547108ec93ea61cf1942a1bcf747b291c..ed1d8c7212da6cdb8911d1fbd6784d499a450b90 100644 (file)
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -49,6 +49,7 @@ struct pstore_private {
        struct pstore_info *psi;
        enum pstore_type_id type;
        u64     id;
+       int     count;
        ssize_t size;
        char    data[];
 };
@@ -175,8 +176,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
        struct pstore_private *p = dentry->d_inode->i_private;
 
        if (p->psi->erase)
-               p->psi->erase(p->type, p->id, dentry->d_inode->i_ctime,
-                             p->psi);
+               p->psi->erase(p->type, p->id, p->count,
+                             dentry->d_inode->i_ctime, p->psi);
 
        return simple_unlink(dir, dentry);
 }
@@ -271,7 +272,7 @@ int pstore_is_mounted(void)
  * Load it up with "size" bytes of data from "buf".
  * Set the mtime & ctime to the date that this record was originally stored.
  */
-int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
+int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
                  char *data, size_t size, struct timespec time,
                  struct pstore_info *psi)
 {
@@ -307,6 +308,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
                goto fail_alloc;
        private->type = type;
        private->id = id;
+       private->count = count;
        private->psi = psi;
 
        switch (type) {

diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 4847f588b7d5079df974c42a2f7324615e477aca..937d820f273c2b17c5b47aa365f230970b19cc32 100644 (file)
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -50,7 +50,7 @@ extern struct pstore_info *psinfo;
 extern void    pstore_set_kmsg_bytes(int);
 extern void    pstore_get_records(int);
 extern int     pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
-                             char *data, size_t size,
+                             int count, char *data, size_t size,
                              struct timespec time, struct pstore_info *psi);
 extern int     pstore_is_mounted(void);
 

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 947fbe06c3b1f2ed0948b8fb050b43f2c48ff591..5ea2e77ff023f8a4060c071ab733f419b1cabc03 100644 (file)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -136,7 +136,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                        break;
 
                ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
-                                   hsize + len, psinfo);
+                                   oopscount, hsize + len, psinfo);
                if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
                        pstore_new_entry = 1;
 
@@ -173,7 +173,7 @@ 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, c, psinfo);
                spin_unlock_irqrestore(&psinfo->buf_lock, flags);
                s += c;
                c = e - s;
@@ -197,7 +197,7 @@ 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,
+                              u64 *id, unsigned int part, int count,
                               size_t size, struct pstore_info *psi)
 {
        return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi);
@@ -267,6 +267,7 @@ 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;
@@ -278,9 +279,9 @@ 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);
+       while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) {
+               rc = pstore_mkfile(type, psi->name, id, count, buf,
+                                 (size_t)size, time, psi);
                kfree(buf);
                buf = NULL;
                if (rc && (rc != -EEXIST || !quiet))

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 749693fcb75a6cad7f63dd007b42a3d6e6a9d3d2..2bfa36e0ffe8d464dde8b74c37c91c46d16d49ae 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -132,9 +132,8 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 }
 
 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
-                                  struct timespec *time,
-                                  char **buf,
-                                  struct pstore_info *psi)
+                                  int *count, struct timespec *time,
+                                  char **buf, struct pstore_info *psi)
 {
        ssize_t size;
        struct ramoops_context *cxt = psi->data;
@@ -236,7 +235,7 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
        return 0;
 }
 
-static int ramoops_pstore_erase(enum pstore_type_id type, u64 id,
+static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
                                struct timespec time, struct pstore_info *psi)
 {
        struct ramoops_context *cxt = psi->data;

diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index f6e93362d25932b7467f121cefd9274fdd830182..1788909d9a99fdc22dbe83b83cd928fec421ad4c 100644 (file)
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -50,17 +50,19 @@ struct pstore_info {
        int             (*open)(struct pstore_info *psi);
        int             (*close)(struct pstore_info *psi);
        ssize_t         (*read)(u64 *id, enum pstore_type_id *type,
-                       struct timespec *time, char **buf,
+                       int *count, struct timespec *time, char **buf,
                        struct pstore_info *psi);
        int             (*write)(enum pstore_type_id type,
                        enum kmsg_dump_reason reason, u64 *id,
-                       unsigned int part, size_t size, struct pstore_info *psi);
+                       unsigned int part, int count, size_t size,
+                       struct pstore_info *psi);
        int             (*write_buf)(enum pstore_type_id type,
                        enum kmsg_dump_reason reason, u64 *id,
                        unsigned int part, const char *buf, size_t size,
                        struct pstore_info *psi);
        int             (*erase)(enum pstore_type_id type, u64 id,
-                       struct timespec time, struct pstore_info *psi);
+                       int count, struct timespec time,
+                       struct pstore_info *psi);
        void            *data;
 };