Merge tag 'please-pull-pstore_mevent' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull pstore fixes from Tony Luck:
 "Patch series to allow EFI variable backend to pstore to hold multiple
  records."

* tag 'please-pull-pstore_mevent' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  efi_pstore: Add a format check for an existing variable name at erasing time
  efi_pstore: Add a format check for an existing variable name at reading time
  efi_pstore: Add a sequence counter to a variable name
  efi_pstore: Add ctime to argument of erase callback
  efi_pstore: Remove a logic erasing entries from a write callback to hold multiple logs
  efi_pstore: Add a logic erasing entries to an erase callback
  efi_pstore: Check remaining space with QueryVariableInfo() before writing data

8 files changed, 144 insertions, 73 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index e4d9d24eb73d..6d894bfd8b8f 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -931,14 +931,14 @@ 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,
-                        struct pstore_info *psi);
+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 = {
         .owner          = THIS_MODULE,
@@ -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 *)
@@ -1101,8 +1101,8 @@ 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,
-                        struct pstore_info *psi)
+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 d10c9873dd9a..6e51c1e81f14 100644
--- 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;
 
@@ -674,21 +675,41 @@ 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;
+                        } else if (sscanf(name, "dump-type%u-%u-%lu",
+                                   type, &part, &time) == 3) {
+                                /*
+                                 * Check if an old format,
+                                 * which doesn't support holding
+                                 * multiple logs, remains.
+                                 */
                                 *id = part;
+                                *count = 0;
                                 timespec->tv_sec = time;
                                 timespec->tv_nsec = 0;
-                                get_var_data_locked(efivars, &efivars->walk_entry->var);
-                                size = efivars->walk_entry->var.DataSize;
-                                *buf = kmalloc(size, GFP_KERNEL);
-                                if (*buf == NULL)
-                                        return -ENOMEM;
-                                memcpy(*buf, efivars->walk_entry->var.Data,
-                                       size);
-                                efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
-                                                   struct efivar_entry, list);
-                                return size;
+                        } else {
+                                efivars->walk_entry = list_entry(
+                                                efivars->walk_entry->list.next,
+                                                struct efivar_entry, list);
+                                continue;
                         }
+
+                        get_var_data_locked(efivars, &efivars->walk_entry->var);
+                        size = efivars->walk_entry->var.DataSize;
+                        *buf = kmalloc(size, GFP_KERNEL);
+                        if (*buf == NULL)
+                                return -ENOMEM;
+                        memcpy(*buf, efivars->walk_entry->var.Data,
+                               size);
+                        efivars->walk_entry = list_entry(
+                                        efivars->walk_entry->list.next,
+                                        struct efivar_entry, list);
+                        return size;
                 }
                 efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
                                                  struct efivar_entry, list);
@@ -698,26 +719,77 @@ 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];
-        char stub_name[DUMP_NAME_LEN];
         efi_char16_t efi_name[DUMP_NAME_LEN];
         efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
         struct efivars *efivars = psi->data;
-        struct efivar_entry *entry, *found = NULL;
         int i, ret = 0;
+        u64 storage_space, remaining_space, max_variable_size;
+        efi_status_t status = EFI_NOT_FOUND;
+
+        spin_lock(&efivars->lock);
+
+        /*
+         * Check if there is a space enough to log.
+         * size: a size of logging data
+         * DUMP_NAME_LEN * 2: a maximum size of variable name
+         */
+        status = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES,
+                                                   &storage_space,
+                                                   &remaining_space,
+                                                   &max_variable_size);
+        if (status || remaining_space < size + DUMP_NAME_LEN * 2) {
+                spin_unlock(&efivars->lock);
+                *id = part;
+                return -ENOSPC;
+        }
+
+        sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count,
+                get_seconds());
+
+        for (i = 0; i < DUMP_NAME_LEN; i++)
+                efi_name[i] = name[i];
+
+        efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
+                                   size, psi->buf);
+
+        spin_unlock(&efivars->lock);
+
+        if (size)
+                ret = efivar_create_sysfs_entry(efivars,
+                                          utf16_strsize(efi_name,
+                                                        DUMP_NAME_LEN * 2),
+                                          efi_name, &vendor);
+
+        *id = part;
+        return ret;
+};
+
+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];
+        efi_char16_t efi_name[DUMP_NAME_LEN];
+        char name_old[DUMP_NAME_LEN];
+        efi_char16_t efi_name_old[DUMP_NAME_LEN];
+        efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+        struct efivars *efivars = psi->data;
+        struct efivar_entry *entry, *found = NULL;
+        int i;
 
-        sprintf(stub_name, "dump-type%u-%u-", type, part);
-        sprintf(name, "%s%lu", stub_name, get_seconds());
+        sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
+                time.tv_sec);
 
         spin_lock(&efivars->lock);
 
         for (i = 0; i < DUMP_NAME_LEN; i++)
-                efi_name[i] = stub_name[i];
+                efi_name[i] = name[i];
 
         /*
-         * Clean up any entries with the same name
+         * Clean up an entry with the same name
          */
 
         list_for_each_entry(entry, &efivars->list, list) {
@@ -726,11 +798,22 @@ static int efi_pstore_write(enum pstore_type_id type,
                 if (efi_guidcmp(entry->var.VendorGuid, vendor))
                         continue;
                 if (utf16_strncmp(entry->var.VariableName, efi_name,
-                                  utf16_strlen(efi_name)))
-                        continue;
-                /* Needs to be a prefix */
-                if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
-                        continue;
+                                  utf16_strlen(efi_name))) {
+                        /*
+                         * Check if an old format,
+                         * which doesn't support holding
+                         * multiple logs, remains.
+                         */
+                        sprintf(name_old, "dump-type%u-%u-%lu", type,
+                                (unsigned int)id, time.tv_sec);
+
+                        for (i = 0; i < DUMP_NAME_LEN; i++)
+                                efi_name_old[i] = name_old[i];
+
+                        if (utf16_strncmp(entry->var.VariableName, efi_name_old,
+                                          utf16_strlen(efi_name_old)))
+                                continue;
+                }
 
                 /* found */
                 found = entry;
@@ -738,37 +821,17 @@ static int efi_pstore_write(enum pstore_type_id type,
                                            &entry->var.VendorGuid,
                                            PSTORE_EFI_ATTRIBUTES,
                                            0, NULL);
+                break;
         }
 
         if (found)
                 list_del(&found->list);
 
-        for (i = 0; i < DUMP_NAME_LEN; i++)
-                efi_name[i] = name[i];
-
-        efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
-                                   size, psi->buf);
-
         spin_unlock(&efivars->lock);
 
         if (found)
                 efivar_unregister(found);
 
-        if (size)
-                ret = efivar_create_sysfs_entry(efivars,
-                                          utf16_strsize(efi_name,
-                                                        DUMP_NAME_LEN * 2),
-                                          efi_name, &vendor);
-
-        *id = part;
-        return ret;
-};
-
-static int efi_pstore_erase(enum pstore_type_id type, u64 id,
-                            struct pstore_info *psi)
-{
-        efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi);
-
         return 0;
 }
 #else
@@ -782,7 +845,7 @@ 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)
 {
@@ -791,13 +854,14 @@ 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,
-                            struct pstore_info *psi)
+static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
+                            struct timespec time, struct pstore_info *psi)
 {
         return 0;
 }
@@ -1237,6 +1301,7 @@ efivars_init(void)
         ops.get_variable = efi.get_variable;
         ops.set_variable = efi.set_variable;
         ops.get_next_variable = efi.get_next_variable;
+        ops.query_variable_info = efi.query_variable_info;
         error = register_efivars(&__efivars, &ops, efi_kobj);
         if (error)
                 goto err_put;
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 4ab572e6d277..ed1d8c7212da 100644
--- 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[];
 };
@@ -175,7 +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, p->psi);
+                p->psi->erase(p->type, p->id, p->count,
+                              dentry->d_inode->i_ctime, p->psi);
 
         return simple_unlink(dir, dentry);
 }
@@ -270,7 +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)
 {
@@ -306,6 +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 4847f588b7d5..937d820f273c 100644
--- 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 947fbe06c3b1..5ea2e77ff023 100644
--- 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 1a4f6da58eab..2bfa36e0ffe8 100644
--- 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;
@@ -236,8 +235,8 @@ 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,
-                                struct pstore_info *psi)
+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;
         struct persistent_ram_zone *prz;
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 8670eb1eb8cd..c47ec36f3f39 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -643,6 +643,7 @@ struct efivar_operations {
         efi_get_variable_t *get_variable;
         efi_get_next_variable_t *get_next_variable;
         efi_set_variable_t *set_variable;
+        efi_query_variable_info_t *query_variable_info;
 };
 
 struct efivars {
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index ee3034a40884..1788909d9a99 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -50,16 +50,18 @@ 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,
+                        int count, struct timespec time,
                         struct pstore_info *psi);
         void            *data;
 };