pstore: Add file extension to pstore file if compressed

In case decompression fails, add a ".enc.z" to indicate the file has
compressed data. This will help user space utilities to figure
out the file contents.

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

3 files changed, 10 insertions, 6 deletions

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 6a4123d1849c..12823845d324 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -275,8 +275,8 @@ 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, int count,
-                  char *data, size_t size, struct timespec time,
-                  struct pstore_info *psi)
+                  char *data, bool compressed, size_t size,
+                  struct timespec time, struct pstore_info *psi)
 {
         struct dentry           *root = pstore_sb->s_root;
         struct dentry           *dentry;
@@ -315,7 +315,8 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 
         switch (type) {
         case PSTORE_TYPE_DMESG:
-                sprintf(name, "dmesg-%s-%lld", psname, id);
+                sprintf(name, "dmesg-%s-%lld%s", psname, id,
+                                                compressed ? ".enc.z" : "");
                 break;
         case PSTORE_TYPE_CONSOLE:
                 sprintf(name, "console-%s", psname);
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 937d820f273c..3b3d305277c4 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -50,8 +50,9 @@ 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,
-                              int count, char *data, size_t size,
-                              struct timespec time, struct pstore_info *psi);
+                              int count, char *data, bool compressed,
+                              size_t size, struct timespec time,
+                              struct pstore_info *psi);
 extern int      pstore_is_mounted(void);
 
 #endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 76bc5c12c0cf..4ffb7ab5e397 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -479,13 +479,15 @@ void pstore_get_records(int quiet)
                         if (unzipped_len > 0) {
                                 buf = big_oops_buf;
                                 size = unzipped_len;
+                                compressed = false;
                         } else {
                                 pr_err("pstore: decompression failed;"
                                         "returned %d\n", unzipped_len);
+                                compressed = true;
                         }
                 }
                 rc = pstore_mkfile(type, psi->name, id, count, buf,
-                                  (size_t)size, time, psi);
+                                  compressed, (size_t)size, time, psi);
                 if (unzipped_len < 0) {
                         /* Free buffer other than big oops */
                         kfree(buf);