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 <ar...@linux.vnet.ibm.com>
---
fs/pstore/ram.c | 36 ++++++++++++++++++++++++++++--------
1 file changed, 28 insertions(+), 8 deletions(-)
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 2927223..4027c20 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);
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