3 files changed, 82 insertions, 14 deletions

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 893b961dcfd8..379a02dc1217 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -24,6 +24,7 @@
 #include <linux/highmem.h>
 #include <linux/time.h>
 #include <linux/init.h>
+#include <linux/list.h>
 #include <linux/string.h>
 #include <linux/mount.h>
 #include <linux/ramfs.h>
@@ -32,13 +33,18 @@
 #include <linux/magic.h>
 #include <linux/pstore.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
 #include <linux/uaccess.h>
 
 #include "internal.h"
 
 #define PSTORE_NAMELEN  64
 
+static DEFINE_SPINLOCK(allpstore_lock);
+static LIST_HEAD(allpstore);
+
 struct pstore_private {
+        struct list_head list;
         struct pstore_info *psi;
         enum pstore_type_id type;
         u64     id;
@@ -81,8 +87,16 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 
 static void pstore_evict_inode(struct inode *inode)
 {
+        struct pstore_private   *p = inode->i_private;
+        unsigned long           flags;
+
         end_writeback(inode);
-        kfree(inode->i_private);
+        if (p) {
+                spin_lock_irqsave(&allpstore_lock, flags);
+                list_del(&p->list);
+                spin_unlock_irqrestore(&allpstore_lock, flags);
+                kfree(p);
+        }
 }
 
 static const struct inode_operations pstore_dir_inode_operations = {
@@ -182,9 +196,23 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
         struct dentry           *root = pstore_sb->s_root;
         struct dentry           *dentry;
         struct inode            *inode;
-        int                     rc;
+        int                     rc = 0;
         char                    name[PSTORE_NAMELEN];
-        struct pstore_private   *private;
+        struct pstore_private   *private, *pos;
+        unsigned long           flags;
+
+        spin_lock_irqsave(&allpstore_lock, flags);
+        list_for_each_entry(pos, &allpstore, list) {
+                if (pos->type == type &&
+                    pos->id == id &&
+                    pos->psi == psi) {
+                        rc = -EEXIST;
+                        break;
+                }
+        }
+        spin_unlock_irqrestore(&allpstore_lock, flags);
+        if (rc)
+                return rc;
 
         rc = -ENOMEM;
         inode = pstore_get_inode(pstore_sb, root->d_inode, S_IFREG | 0444, 0);
@@ -229,6 +257,10 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id,
 
         d_add(dentry, inode);
 
+        spin_lock_irqsave(&allpstore_lock, flags);
+        list_add(&private->list, &allpstore);
+        spin_unlock_irqrestore(&allpstore_lock, flags);
+
         mutex_unlock(&root->d_inode->i_mutex);
 
         return 0;
@@ -277,7 +309,7 @@ int pstore_fill_super(struct super_block *sb, void *data, int silent)
                 goto fail;
         }
 
-        pstore_get_records();
+        pstore_get_records(0);
 
         return 0;
 fail:
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 611c1b3c46fa..3bde461c3f34 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -1,5 +1,5 @@
 extern void     pstore_set_kmsg_bytes(int);
-extern void     pstore_get_records(void);
+extern void     pstore_get_records(int);
 extern int      pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
                               char *data, size_t size,
                               struct timespec time, struct pstore_info *psi);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index c5300ec31696..ca60ebcfb15f 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -25,12 +25,29 @@
 #include <linux/module.h>
 #include <linux/pstore.h>
 #include <linux/string.h>
+#include <linux/timer.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/workqueue.h>
 
 #include "internal.h"
 
 /*
+ * We defer making "oops" entries appear in pstore - see
+ * whether the system is actually still running well enough
+ * to let someone see the entry
+ */
+#define PSTORE_INTERVAL (60 * HZ)
+
+static int pstore_new_entry;
+
+static void pstore_timefunc(unsigned long);
+static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
+
+static void pstore_dowork(struct work_struct *);
+static DECLARE_WORK(pstore_work, pstore_dowork);
+
+/*
  * pstore_lock just protects "psinfo" during
  * calls to pstore_register()
  */
@@ -100,9 +117,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                 id = psinfo->write(PSTORE_TYPE_DMESG, part,
                                    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);
+                        pstore_new_entry = 1;
                 l1 -= l1_cpy;
                 l2 -= l2_cpy;
                 total += l1_cpy + l2_cpy;
@@ -148,19 +163,24 @@ int pstore_register(struct pstore_info *psi)
         }
 
         if (pstore_is_mounted())
-                pstore_get_records();
+                pstore_get_records(0);
 
         kmsg_dump_register(&pstore_dumper);
 
+        pstore_timer.expires = jiffies + PSTORE_INTERVAL;
+        add_timer(&pstore_timer);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);
 
 /*
- * Read all the records from the persistent store. Create and
- * file files in our filesystem.
+ * Read all the records from the persistent store. Create
+ * files in our filesystem.  Don't warn about -EEXIST errors
+ * when we are re-scanning the backing store looking to add new
+ * error records.
  */
-void pstore_get_records(void)
+void pstore_get_records(int quiet)
 {
         struct pstore_info *psi = psinfo;
         ssize_t                 size;
@@ -178,8 +198,9 @@ void pstore_get_records(void)
                 goto out;
 
         while ((size = psi->read(&id, &type, &time, psi)) > 0) {
-                if (pstore_mkfile(type, psi->name, id, psi->buf, (size_t)size,
-                                  time, psi))
+                rc = pstore_mkfile(type, psi->name, id, psi->buf, (size_t)size,
+                                  time, psi);
+                if (rc && (rc != -EEXIST || !quiet))
                         failed++;
         }
         psi->close(psi);
@@ -191,6 +212,21 @@ out:
                        failed, psi->name);
 }
 
+static void pstore_dowork(struct work_struct *work)
+{
+        pstore_get_records(1);
+}
+
+static void pstore_timefunc(unsigned long dummy)
+{
+        if (pstore_new_entry) {
+                pstore_new_entry = 0;
+                schedule_work(&pstore_work);
+        }
+
+        mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL);
+}
+
 /*
  * Call platform driver to write a record to the
  * persistent store.