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-rw-r--r--src/pstore/pstore.c204
1 files changed, 83 insertions, 121 deletions
diff --git a/src/pstore/pstore.c b/src/pstore/pstore.c
index f8e6582d5b..6c3d577507 100644
--- a/src/pstore/pstore.c
+++ b/src/pstore/pstore.c
@@ -114,7 +114,7 @@ static int compare_pstore_entries(const PStoreEntry *a, const PStoreEntry *b) {
return strcmp(a->dirent.d_name, b->dirent.d_name);
}
-static int move_file(PStoreEntry *pe, const char *subdir) {
+static int move_file(PStoreEntry *pe, const char *subdir1, const char *subdir2) {
_cleanup_free_ char *ifd_path = NULL, *ofd_path = NULL;
_cleanup_free_ void *field = NULL;
const char *suffix, *message;
@@ -128,7 +128,7 @@ static int move_file(PStoreEntry *pe, const char *subdir) {
if (!ifd_path)
return log_oom();
- ofd_path = path_join(arg_archivedir, subdir, pe->dirent.d_name);
+ ofd_path = path_join(arg_archivedir, subdir1, subdir2, pe->dirent.d_name);
if (!ofd_path)
return log_oom();
@@ -171,153 +171,115 @@ static int move_file(PStoreEntry *pe, const char *subdir) {
return 0;
}
-static int write_dmesg(const char *dmesg, size_t size, const char *id) {
- _cleanup_(unlink_and_freep) char *tmp_path = NULL;
+static int append_dmesg(PStoreEntry *pe, const char *subdir1, const char *subdir2) {
+ /* Append dmesg chunk to end, create if needed */
_cleanup_free_ char *ofd_path = NULL;
_cleanup_close_ int ofd = -1;
ssize_t wr;
- int r;
- if (size == 0)
- return 0;
+ assert(pe);
- assert(dmesg);
+ if (pe->content_size == 0)
+ return 0;
- ofd_path = path_join(arg_archivedir, id, "dmesg.txt");
+ ofd_path = path_join(arg_archivedir, subdir1, subdir2, "dmesg.txt");
if (!ofd_path)
return log_oom();
- ofd = open_tmpfile_linkable(ofd_path, O_CLOEXEC|O_CREAT|O_TRUNC|O_WRONLY, &tmp_path);
+ ofd = open(ofd_path, O_CREAT|O_NOFOLLOW|O_NOCTTY|O_CLOEXEC|O_APPEND|O_WRONLY, 0640);
if (ofd < 0)
- return log_error_errno(ofd, "Failed to open temporary file %s: %m", ofd_path);
- wr = write(ofd, dmesg, size);
+ return log_error_errno(ofd, "Failed to open file %s: %m", ofd_path);
+ wr = write(ofd, pe->content, pe->content_size);
if (wr < 0)
return log_error_errno(errno, "Failed to store dmesg to %s: %m", ofd_path);
- if (wr != (ssize_t)size)
- return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, size - wr);
- r = link_tmpfile(ofd, tmp_path, ofd_path);
- if (r < 0)
- return log_error_errno(r, "Failed to write temporary file %s: %m", ofd_path);
- tmp_path = mfree(tmp_path);
+ if ((size_t)wr != pe->content_size)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, pe->content_size - wr);
return 0;
}
-static void process_dmesg_files(PStoreList *list) {
+static int process_dmesg_files(PStoreList *list) {
/* Move files, reconstruct dmesg.txt */
- _cleanup_free_ char *dmesg = NULL, *dmesg_id = NULL;
- size_t dmesg_size = 0;
- bool dmesg_bad = false;
- PStoreEntry *pe;
+ _cleanup_free_ char *erst_subdir = NULL;
+ uint64_t last_record_id = 0;
+
+ /* When dmesg is written into pstore, it is done so in small chunks, whatever the exchange buffer
+ * size is with the underlying pstore backend (ie. EFI may be ~2KiB), which means an example
+ * pstore with approximately 64KB of storage may have up to roughly 32 dmesg files, some likely
+ * related.
+ *
+ * Here we look at the dmesg filename and try to discern if files are part of a related group,
+ * meaning the same original dmesg.
+ *
+ * The dmesg- filename contains the backend-type and the Common Platform Error Record, CPER,
+ * record id, a 64-bit number.
+ *
+ * Files are processed in reverse lexigraphical order so as to properly reconstruct original dmesg.*/
- /* Handle each dmesg file: files processed in reverse
- * order so as to properly reconstruct original dmesg */
for (size_t n = list->n_entries; n > 0; n--) {
- bool move_file_and_continue = false;
- _cleanup_free_ char *pe_id = NULL;
+ PStoreEntry *pe;
char *p;
- size_t plen;
pe = &list->entries[n-1];
if (pe->handled)
continue;
- if (!startswith(pe->dirent.d_name, "dmesg-"))
- continue;
-
if (endswith(pe->dirent.d_name, ".enc.z")) /* indicates a problem */
- move_file_and_continue = true;
- p = strrchr(pe->dirent.d_name, '-');
- if (!p)
- move_file_and_continue = true;
-
- if (move_file_and_continue) {
- /* A dmesg file on which we do NO additional processing */
- (void) move_file(pe, NULL);
- continue;
- }
-
- /* See if this file is one of a related group of files
- * in order to reconstruct dmesg */
-
- /* When dmesg is written into pstore, it is done so in
- * small chunks, whatever the exchange buffer size is
- * with the underlying pstore backend (ie. EFI may be
- * ~2KiB), which means an example pstore with approximately
- * 64KB of storage may have up to roughly 32 dmesg files
- * that could be related, depending upon the size of the
- * original dmesg.
- *
- * Here we look at the dmesg filename and try to discern
- * if files are part of a related group, meaning the same
- * original dmesg.
- *
- * The two known pstore backends are EFI and ERST. These
- * backends store data in the Common Platform Error
- * Record, CPER, format. The dmesg- filename contains the
- * CPER record id, a 64bit number (in decimal notation).
- * In Linux, the record id is encoded with two digits for
- * the dmesg part (chunk) number and 3 digits for the
- * count number. So allowing an additional digit to
- * compensate for advancing time, this code ignores the
- * last six digits of the filename in determining the
- * record id.
- *
- * For the EFI backend, the record id encodes an id in the
- * upper 32 bits, and a timestamp in the lower 32-bits.
- * So ignoring the least significant 6 digits has proven
- * to generally identify related dmesg entries. */
-#define PSTORE_FILENAME_IGNORE 6
-
- /* determine common portion of record id */
- ++p; /* move beyond dmesg- */
- plen = strlen(p);
- if (plen > PSTORE_FILENAME_IGNORE) {
- pe_id = memdup_suffix0(p, plen - PSTORE_FILENAME_IGNORE);
- if (!pe_id) {
- log_oom();
- return;
- }
- } else
- pe_id = mfree(pe_id);
-
- /* Now move file from pstore to archive storage */
- move_file(pe, pe_id);
-
- if (dmesg_bad)
continue;
-
- /* If the current record id is NOT the same as the
- * previous record id, then start a new dmesg.txt file */
- if (!streq_ptr(pe_id, dmesg_id)) {
- /* Encountered a new dmesg group, close out old one, open new one */
- (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
- dmesg_size = 0;
-
- /* now point dmesg_id to storage of pe_id */
- free_and_replace(dmesg_id, pe_id);
- }
-
- /* Reconstruction of dmesg is done as a useful courtesy: do not fail, but don't write garbled
- * output either. */
- size_t needed = strlen(pe->dirent.d_name) + strlen(":\n") + pe->content_size + 1;
- if (!GREEDY_REALLOC(dmesg, dmesg_size + needed)) {
- log_oom();
- dmesg_bad = true;
+ if (!startswith(pe->dirent.d_name, "dmesg-"))
continue;
- }
-
- dmesg_size += sprintf(dmesg + dmesg_size, "%s:\n", pe->dirent.d_name);
- if (pe->content) {
- memcpy(dmesg + dmesg_size, pe->content, pe->content_size);
- dmesg_size += pe->content_size;
- }
- pe_id = mfree(pe_id);
+ if ((p = startswith(pe->dirent.d_name, "dmesg-efi-"))) {
+ /* For the EFI backend, the 3 least significant digits of record id encodes a
+ * "count" number, the next 2 least significant digits for the dmesg part
+ * (chunk) number, and the remaining digits as the timestamp. See
+ * linux/drivers/firmware/efi/efi-pstore.c in efi_pstore_write(). */
+ _cleanup_free_ char *subdir1 = NULL, *subdir2 = NULL;
+ size_t plen = strlen(p);
+
+ if (plen < 6)
+ continue;
+
+ /* Extract base record id */
+ subdir1 = strndup(p, plen - 5);
+ if (!subdir1)
+ return log_oom();
+ /* Extract "count" field */
+ subdir2 = strndup(p + plen - 3, 3);
+ if (!subdir2)
+ return log_oom();
+
+ /* Now move file from pstore to archive storage */
+ (void) move_file(pe, subdir1, subdir2);
+
+ /* Append to the dmesg */
+ (void) append_dmesg(pe, subdir1, subdir2);
+ } else if ((p = startswith(pe->dirent.d_name, "dmesg-erst-"))) {
+ /* For the ERST backend, the record is a monotonically increasing number, seeded as
+ * a timestamp. See linux/drivers/acpi/apei/erst.c in erst_writer(). */
+ uint64_t record_id;
+
+ if (safe_atou64(p, &record_id) < 0)
+ continue;
+ if (last_record_id - 1 != record_id)
+ /* A discontinuity in the number has been detected, this current record id
+ * will become the directory name for all pieces of the dmesg in this
+ * series. */
+ if (free_and_strdup(&erst_subdir, p) < 0)
+ return log_oom();
+
+ /* Now move file from pstore to archive storage */
+ (void) move_file(pe, erst_subdir, NULL);
+
+ /* Append to the dmesg */
+ (void) append_dmesg(pe, erst_subdir, NULL);
+
+ /* Update, but keep erst_subdir for next file */
+ last_record_id = record_id;
+ } else
+ log_debug("Unknown backend, ignoring \"%s\".", pe->dirent.d_name);
}
-
- if (!dmesg_bad)
- (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
+ return 0;
}
static int list_files(PStoreList *list, const char *sourcepath) {
@@ -393,11 +355,11 @@ static int run(int argc, char *argv[]) {
typesafe_qsort(list.entries, list.n_entries, compare_pstore_entries);
/* Process known file types */
- process_dmesg_files(&list);
+ (void) process_dmesg_files(&list);
/* Move left over files out of pstore */
for (size_t n = 0; n < list.n_entries; n++)
- move_file(&list.entries[n], NULL);
+ (void) move_file(&list.entries[n], NULL, NULL);
return 0;
}
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