pstore: Extend API for more flexibility in new backends

Some pstore implementations may not have a static context, so extend the
API to pass the pstore_info struct to all calls and allow for a context
pointer.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

5 files changed, 31 insertions, 20 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index e6cef8e1b534..de3ae92adaa5 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -932,8 +932,10 @@ 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,
-                       struct timespec *time);
-static u64 erst_writer(enum pstore_type_id type, size_t size);
+                           struct timespec *time, struct pstore_info *psi);
+static u64 erst_writer(enum pstore_type_id type, size_t size,
+                       struct pstore_info *psi);
+static int erst_clearer(u64 id, struct pstore_info *psi);
 
 static struct pstore_info erst_info = {
         .owner          = THIS_MODULE,
@@ -942,7 +944,7 @@ static struct pstore_info erst_info = {
         .close          = erst_close_pstore,
         .read           = erst_reader,
         .write          = erst_writer,
-        .erase          = erst_clear
+        .erase          = erst_clearer
 };
 
 #define CPER_CREATOR_PSTORE                                             \
@@ -983,7 +985,7 @@ static int erst_close_pstore(struct pstore_info *psi)
 }
 
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
-                       struct timespec *time)
+                           struct timespec *time, struct pstore_info *psi)
 {
         int rc;
         ssize_t len = 0;
@@ -1037,7 +1039,8 @@ out:
         return (rc < 0) ? rc : (len - sizeof(*rcd));
 }
 
-static u64 erst_writer(enum pstore_type_id type, size_t size)
+static u64 erst_writer(enum pstore_type_id type, size_t size,
+                       struct pstore_info *psi)
 {
         struct cper_pstore_record *rcd = (struct cper_pstore_record *)
                                         (erst_info.buf - sizeof(*rcd));
@@ -1080,6 +1083,11 @@ static u64 erst_writer(enum pstore_type_id type, size_t size)
         return rcd->hdr.record_id;
 }
 
+static int erst_clearer(u64 id, struct pstore_info *psi)
+{
+        return erst_clear(id);
+}
+
 static int __init erst_init(void)
 {
         int rc = 0;
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 977ed2723845..b19884a1ba77 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -40,7 +40,7 @@
 
 struct pstore_private {
         u64     id;
-        int     (*erase)(u64);
+        struct pstore_info *psi;
         ssize_t size;
         char    data[];
 };
@@ -73,7 +73,7 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 {
         struct pstore_private *p = dentry->d_inode->i_private;
 
-        p->erase(p->id);
+        p->psi->erase(p->id, p->psi);
 
         return simple_unlink(dir, dentry);
 }
@@ -175,8 +175,8 @@ int pstore_is_mounted(void)
  * 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,
-                              char *data, size_t size,
-                              struct timespec time, int (*erase)(u64))
+                  char *data, size_t size, struct timespec time,
+                  struct pstore_info *psi)
 {
         struct dentry           *root = pstore_sb->s_root;
         struct dentry           *dentry;
@@ -193,7 +193,7 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
         if (!private)
                 goto fail_alloc;
         private->id = id;
-        private->erase = erase;
+        private->psi = psi;
 
         switch (type) {
         case PSTORE_TYPE_DMESG:
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 8c9f23eb1645..611c1b3c46fa 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -2,5 +2,5 @@ extern void	pstore_set_kmsg_bytes(int);
 extern void     pstore_get_records(void);
 extern int      pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
                               char *data, size_t size,
-                              struct timespec time, int (*erase)(u64));
+                              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 f2c3ff20ea68..221c04e5e333 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -94,11 +94,12 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                 memcpy(dst, s1 + s1_start, l1_cpy);
                 memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
 
-                id = psinfo->write(PSTORE_TYPE_DMESG, hsize + l1_cpy + l2_cpy);
+                id = psinfo->write(PSTORE_TYPE_DMESG, hsize + l1_cpy + l2_cpy,
+                                   psinfo);
                 if (reason == KMSG_DUMP_OOPS && pstore_is_mounted())
                         pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id,
                                       psinfo->buf, hsize + l1_cpy + l2_cpy,
-                                      CURRENT_TIME, psinfo->erase);
+                                      CURRENT_TIME, psinfo);
                 l1 -= l1_cpy;
                 l2 -= l2_cpy;
                 total += l1_cpy + l2_cpy;
@@ -166,9 +167,9 @@ void pstore_get_records(void)
         if (rc)
                 goto out;
 
-        while ((size = psi->read(&id, &type, &time)) > 0) {
+        while ((size = psi->read(&id, &type, &time, psi)) > 0) {
                 if (pstore_mkfile(type, psi->name, id, psi->buf, (size_t)size,
-                                  time, psi->erase))
+                                  time, psi))
                         failed++;
         }
         psi->close(psi);
@@ -196,10 +197,10 @@ int pstore_write(enum pstore_type_id type, char *buf, size_t size)
 
         mutex_lock(&psinfo->buf_mutex);
         memcpy(psinfo->buf, buf, size);
-        id = psinfo->write(type, size);
+        id = psinfo->write(type, size, psinfo);
         if (pstore_is_mounted())
                 pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, psinfo->buf,
-                              size, CURRENT_TIME, psinfo->erase);
+                              size, CURRENT_TIME, psinfo);
         mutex_unlock(&psinfo->buf_mutex);
 
         return 0;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 2455ef2683f0..b2f1d97f6909 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -38,9 +38,11 @@ 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);
-        u64             (*write)(enum pstore_type_id type, size_t size);
-        int             (*erase)(u64 id);
+                        struct timespec *time, struct pstore_info *psi);
+        u64             (*write)(enum pstore_type_id type, size_t size,
+                        struct pstore_info *psi);
+        int             (*erase)(u64 id, struct pstore_info *psi);
+        void            *data;
 };
 
 #ifdef CONFIG_PSTORE