readahead: store inode numbers in pack file

If the inode nr for each file is available in the pack file we can
easily detect replaced files (like they result from package upgrades)
which we can then skip to readahead.

1 files changed, 20 insertions, 3 deletions

diff --git a/src/readahead/readahead-replay.c b/src/readahead/readahead-replay.c
index a6529f8bac..886e16f296 100644
--- a/src/readahead/readahead-replay.c
+++ b/src/readahead/readahead-replay.c
@@ -53,6 +53,7 @@ static int unpack_file(FILE *pack) {
         int r = 0, fd = -1;
         bool any = false;
         struct stat st;
+        uint64_t inode;
 
         assert(pack);
 
@@ -62,7 +63,8 @@ static int unpack_file(FILE *pack) {
         char_array_0(fn);
         truncate_nl(fn);
 
-        if ((fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW)) < 0) {
+        fd = open(fn, O_RDONLY|O_CLOEXEC|O_NOATIME|O_NOCTTY|O_NOFOLLOW);
+        if (fd < 0) {
 
                 if (errno != ENOENT && errno != EPERM && errno != EACCES)
                         log_warning("open(%s) failed: %m", fn);
@@ -72,6 +74,21 @@ static int unpack_file(FILE *pack) {
                 fd = -1;
         }
 
+        if (fread(&inode, sizeof(inode), 1, pack) != 1) {
+                log_error("Premature end of pack file.");
+                r = -EIO;
+                goto finish;
+        }
+
+        if (fd >= 0) {
+                /* If the inode changed the file got deleted, so just
+                 * ignore this entry */
+                if (st.st_ino != (uint64_t) inode) {
+                        close_nointr_nofail(fd);
+                        fd = -1;
+                }
+        }
+
         for (;;) {
                 uint32_t b, c;
 
@@ -166,8 +183,8 @@ static int replay(const char *root) {
 
         char_array_0(line);
 
-        if (!streq(line, CANONICAL_HOST "\n")) {
-                log_debug("Pack file host type mismatch.");
+        if (!streq(line, CANONICAL_HOST ";VERSION=2\n")) {
+                log_debug("Pack file host or version type mismatch.");
                 goto finish;
         }