From: Liu ShuoX <shuox....@intel.com>

dump the records in runtime is useful sometime. We could check the
records and understand driver's and device's status.

Signed-off-by: Zhang Yanmin <yanmin.zh...@intel.com>
Signed-off-by: Liu ShuoX <shuox....@intel.com>
---
 fs/pstore/inode.c          | 32 ++++++++++++++++++++++++++------
 fs/pstore/internal.h       |  3 ++-
 fs/pstore/platform.c       | 39 ++++++++++++++++++++++++++++++---------
 fs/pstore/ram.c            | 18 ++++++++++++++++++
 fs/pstore/ram_core.c       | 10 ++++++++++
 include/linux/pstore.h     |  2 ++
 include/linux/pstore_ram.h | 15 +++++++++++++++
 7 files changed, 103 insertions(+), 16 deletions(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index a9c9782..64adfb8 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -48,10 +48,11 @@ struct pstore_private {
        struct list_head list;
        struct pstore_info *psi;
        enum pstore_type_id type;
+       int     curr;
        u64     id;
        int     count;
        ssize_t size;
-       char    data[];
+       char    *data;
 };
struct pstore_seq_data {
@@ -220,6 +221,14 @@ static int pstore_file_open(struct inode *inode, struct 
file *file)
                        sops = zones[ps->id].seq_ops;
                else
                        sops = &pstore_seq_ops;
+               if (ps->curr) {
+                       /*
+                        * Update size again as current buffer
+                        * size might be changed.
+                        */
+                       inode->i_size = ps->size =
+                               persistent_ram_size(cxt->norm_przs[ps->id]);
+               }
        }
err = seq_open(file, sops);
@@ -256,12 +265,16 @@ static int pstore_unlink(struct inode *dir, struct dentry 
*dentry)
 {
        struct pstore_private *p = dentry->d_inode->i_private;
+ if (p->curr)
+               goto unlink;
        if (p->psi->erase)
                p->psi->erase(p->type, p->id, p->count,
                              dentry->d_inode->i_ctime, p->psi);
        else
                return -EPERM;
+ kfree(p->data);
+unlink:
        return simple_unlink(dir, dentry);
 }
@@ -358,7 +371,7 @@ int pstore_is_mounted(void)
  */
 int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
                  char *data, bool compressed, size_t size,
-                 struct timespec time, struct pstore_info *psi)
+                 struct timespec time, struct pstore_info *psi, bool curr)
 {
        struct dentry           *root = pstore_sb->s_root;
        struct dentry           *dentry;
@@ -374,14 +387,15 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, 
u64 id, int count,
        list_for_each_entry(pos, &allpstore, list) {
                if (pos->type == type &&
                    pos->id == id &&
-                   pos->psi == psi) {
+                   pos->psi == psi &&
+                   pos->curr == curr) {
                        rc = -EEXIST;
                        break;
                }
        }
        spin_unlock_irqrestore(&allpstore_lock, flags);
        if (rc)
-               return rc;
+               goto fail;
rc = -ENOMEM;
        inode = pstore_get_inode(pstore_sb);
@@ -389,13 +403,15 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, 
u64 id, int count,
                goto fail;
        inode->i_mode = S_IFREG | 0444;
        inode->i_fop = &pstore_file_operations;
-       private = kmalloc(sizeof *private + size, GFP_KERNEL);
+       private = kmalloc(sizeof(*private), GFP_KERNEL);
        if (!private)
                goto fail_alloc;
        private->type = type;
        private->id = id;
        private->count = count;
        private->psi = psi;
+       private->curr = curr;
+       private->data = data;
switch (type) {
        case PSTORE_TYPE_DMESG:
@@ -434,13 +450,15 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, 
u64 id, int count,
                break;
        }
+ if (curr)
+               strcat(name, "_cur");
+
        mutex_lock(&root->d_inode->i_mutex);
dentry = d_alloc_name(root, name);
        if (!dentry)
                goto fail_lockedalloc;
- memcpy(private->data, data, size);
        inode->i_size = private->size = size;
inode->i_private = private;
@@ -465,6 +483,7 @@ fail_alloc:
        iput(inode);
fail:
+       kfree(data);
        return rc;
 }
@@ -497,6 +516,7 @@ static int pstore_fill_super(struct super_block *sb, void *data, int silent)
                return -ENOMEM;
pstore_get_records(0);
+       pstore_get_cur_records();
return 0;
 }
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 86623ee..ccc0f35 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -50,10 +50,11 @@ extern struct pstore_info *psinfo;
extern void pstore_set_kmsg_bytes(int);
 extern void    pstore_get_records(int);
+extern void    pstore_get_cur_records(void);
 extern int     pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
                              int count, char *data, bool compressed,
                              size_t size, struct timespec time,
-                             struct pstore_info *psi);
+                             struct pstore_info *psi, bool curr);
 extern int     pstore_is_mounted(void);
#endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 46d269e..6a3cbbb 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -439,8 +439,10 @@ int pstore_register(struct pstore_info *psi)
allocate_buf_for_compression(); - if (pstore_is_mounted())
+       if (pstore_is_mounted()) {
                pstore_get_records(0);
+               pstore_get_cur_records();
+       }
kmsg_dump_register(&pstore_dumper); @@ -498,7 +500,13 @@ void pstore_get_records(int quiet) if (unzipped_len > 0) {
                                kfree(buf);
-                               buf = big_oops_buf;
+                               buf = kmalloc(unzipped_len, GFP_KERNEL);
+                               if (!buf) {
+                                       if (!quiet)
+                                               failed++;
+                                       continue;
+                               }
+                               memcpy(buf, big_oops_buf, unzipped_len);
                                size = unzipped_len;
                                compressed = false;
                        } else {
@@ -508,15 +516,10 @@ void pstore_get_records(int quiet)
                        }
                }
                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;
+                                 compressed, (size_t)size, time, psi, false);
                if (rc && (rc != -EEXIST || !quiet))
                        failed++;
+               unzipped_len = -1;
        }
        if (psi->close)
                psi->close(psi);
@@ -528,6 +531,24 @@ out:
                       failed, psi->name);
 }
+void pstore_get_cur_records(void)
+{
+       struct pstore_info *psi = psinfo;
+       ssize_t         size;
+       char            *buf = NULL;
+       struct timespec time = {0};
+       u64             id = 0;
+       int             rc;
+
+       if (!psi || !psi->read_curr)
+               return;
+
+       while (size = psi->read_curr(&id, PSTORE_TYPE_NORM, &buf, psi), buf) {
+               rc = pstore_mkfile(PSTORE_TYPE_NORM, psi->name, id - 1, 0, buf,
+                               0, (size_t)size, time, psi, true);
+       }
+}
+
 static void pstore_dowork(struct work_struct *work)
 {
        pstore_get_records(1);
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index e1f2adc..67c9ced 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -141,6 +141,23 @@ static void ramoops_read_kmsg_hdr(char *buffer, struct 
timespec *time,
        }
 }
+/* only support PSTORE_TYPE_NORM type ram zone */
+static ssize_t ramoops_pstore_read_current(u64 *id, enum pstore_type_id type,
+               char **buf, struct pstore_info *psi)
+{
+       struct ramoops_context *cxt = psi->data;
+       struct persistent_ram_zone *prz;
+
+       if (type != PSTORE_TYPE_NORM || (*id >= cxt->norm_num)) {
+               *buf = NULL;
+               return 0;
+       }
+       prz = cxt->norm_przs[(*id)++];
+       *buf = persistent_ram_buffer(prz);
+
+       return persistent_ram_size(prz);
+}
+
 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
                                   int *count, struct timespec *time,
                                   char **buf, bool *compressed,
@@ -309,6 +326,7 @@ static struct ramoops_context oops_cxt = {
                .name   = "ramoops",
                .open   = ramoops_pstore_open,
                .read   = ramoops_pstore_read,
+               .read_curr      = ramoops_pstore_read_current,
                .write_buf      = ramoops_pstore_write_buf,
                .erase  = ramoops_pstore_erase,
        },
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 9c25a0f..72a34b5 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -46,6 +46,11 @@ static inline size_t buffer_start(struct persistent_ram_zone 
*prz)
        return atomic_read(&prz->buffer->start);
 }
+void *persistent_ram_buffer(struct persistent_ram_zone *prz)
+{
+       return prz->buffer->data;
+}
+
 /* increase and wrap the start pointer, returning the old value */
 static size_t buffer_start_add_atomic(struct persistent_ram_zone *prz, size_t 
a)
 {
@@ -370,6 +375,11 @@ notrace void *persistent_ram_new_record(struct 
persistent_ram_zone *prz)
                        buffer_start_add(prz, record_size));
 }
+size_t persistent_ram_size(struct persistent_ram_zone *prz)
+{
+       return buffer_size(prz);
+}
+
 size_t persistent_ram_old_size(struct persistent_ram_zone *prz)
 {
        return prz->old_log_size;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 9936859..31a6ec1 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -59,6 +59,8 @@ struct pstore_info {
        ssize_t         (*read)(u64 *id, enum pstore_type_id *type,
                        int *count, struct timespec *time, char **buf,
                        bool *compressed, struct pstore_info *psi);
+       ssize_t         (*read_curr)(u64 *id, enum pstore_type_id type,
+                       char **buf, struct pstore_info *psi);
        int             (*write)(enum pstore_type_id type,
                        enum kmsg_dump_reason reason, u64 *id,
                        unsigned int part, int count, bool compressed,
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index d7d0b7a..9134bda 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -72,4 +72,19 @@ void persistent_ram_free_old(struct persistent_ram_zone 
*prz);
 ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
        char *str, size_t len);
+#ifdef CONFIG_PSTORE_RAM
+void *persistent_ram_buffer(struct persistent_ram_zone *prz);
+size_t persistent_ram_size(struct persistent_ram_zone *prz);
+#else
+static inline void *persistent_ram_buffer(struct persistent_ram_zone *prz)
+{
+       return NULL;
+}
+
+static inline size_t persistent_ram_size(struct persistent_ram_zone *prz)
+{
+       return 0;
+}
+#endif
+
 #endif
--
1.8.3.2

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