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authorAruna Balakrishnaiah <aruna@linux.vnet.ibm.com>2013-08-16 13:58:00 -0700
committerTony Luck <tony.luck@intel.com>2013-08-19 11:53:50 -0700
commit3f8f80f0cfebab185b6fe599c53b63e7e8ae02c9 (patch)
tree4176db7f1cb1868b6ceb589061df2112f23c0e1f /fs/pstore
parentf8c62f34fe868f5bcca88a32e4a5c52b67de661d (diff)
downloadlinux-3f8f80f0cfebab185b6fe599c53b63e7e8ae02c9.tar.bz2
pstore/ram: Read and write to the 'compressed' flag of pstore
In pstore write, add character 'C'(compressed) or 'D'(decompressed) in the header while writing to Ram persistent buffer. In pstore read, read the header and update the 'compressed' flag accordingly. 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>
Diffstat (limited to 'fs/pstore')
-rw-r--r--fs/pstore/ram.c36
1 files changed, 28 insertions, 8 deletions
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 292722327811..4027c2065842 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -131,6 +131,27 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
return prz;
}
+static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
+ bool *compressed)
+{
+ char data_type;
+
+ if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
+ &time->tv_sec, &time->tv_nsec, &data_type) == 3) {
+ if (data_type == 'C')
+ *compressed = true;
+ else
+ *compressed = false;
+ } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
+ &time->tv_sec, &time->tv_nsec) == 2) {
+ *compressed = false;
+ } else {
+ time->tv_sec = 0;
+ time->tv_nsec = 0;
+ *compressed = false;
+ }
+}
+
static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
int *count, struct timespec *time,
char **buf, bool *compressed,
@@ -153,10 +174,6 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
if (!prz)
return 0;
- /* TODO(kees): Bogus time for the moment. */
- time->tv_sec = 0;
- time->tv_nsec = 0;
-
size = persistent_ram_old_size(prz);
/* ECC correction notice */
@@ -167,12 +184,14 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
return -ENOMEM;
memcpy(*buf, persistent_ram_old(prz), size);
+ ramoops_read_kmsg_hdr(*buf, time, compressed);
persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
return size + ecc_notice_size;
}
-static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
+static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
+ bool compressed)
{
char *hdr;
struct timespec timestamp;
@@ -183,8 +202,9 @@ static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
timestamp.tv_sec = 0;
timestamp.tv_nsec = 0;
}
- hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
- (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000));
+ hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
+ (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
+ compressed ? 'C' : 'D');
WARN_ON_ONCE(!hdr);
len = hdr ? strlen(hdr) : 0;
persistent_ram_write(prz, hdr, len);
@@ -243,7 +263,7 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
prz = cxt->przs[cxt->dump_write_cnt];
- hlen = ramoops_write_kmsg_hdr(prz);
+ hlen = ramoops_write_kmsg_hdr(prz, compressed);
if (size + hlen > prz->buffer_size)
size = prz->buffer_size - hlen;
persistent_ram_write(prz, buf, size);