From 189455ab08a70f0c80a11847b65ce38563b9332a Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 4 May 2012 00:34:12 +0200
Subject: 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.
---
 src/readahead/readahead-collect.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

(limited to 'src/readahead/readahead-collect.c')

diff --git a/src/readahead/readahead-collect.c b/src/readahead/readahead-collect.c
index a88e7f2d70..359b97bf04 100644
--- a/src/readahead/readahead-collect.c
+++ b/src/readahead/readahead-collect.c
@@ -86,6 +86,7 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
         void *start = MAP_FAILED;
         uint8_t *vec;
         uint32_t b, c;
+        uint64_t inode;
         size_t l, pages;
         bool mapped;
         int r = 0, fd = -1, k;
@@ -93,7 +94,8 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
         assert(pack);
         assert(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)
                         return 0;
@@ -106,7 +108,8 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
                 goto finish;
         }
 
-        if ((k = file_verify(fd, fn, arg_file_size_max, &st)) <= 0) {
+        k = file_verify(fd, fn, arg_file_size_max, &st);
+        if (k <= 0) {
                 r = k;
                 goto finish;
         }
@@ -115,14 +118,14 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
                 btrfs_defrag(fd);
 
         l = PAGE_ALIGN(st.st_size);
-        if ((start = mmap(NULL, l, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+        start = mmap(NULL, l, PROT_READ, MAP_SHARED, fd, 0);
+        if (start == MAP_FAILED) {
                 log_warning("mmap(%s) failed: %m", fn);
                 r = -errno;
                 goto finish;
         }
 
         pages = l / page_size();
-
         vec = alloca(pages);
         memset(vec, 0, pages);
         if (mincore(start, l, vec) < 0) {
@@ -134,6 +137,10 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) {
         fputs(fn, pack);
         fputc('\n', pack);
 
+        /* Store the inode, so that we notice when the file is deleted */
+        inode = (uint64_t) st.st_ino;
+        fwrite(&inode, sizeof(inode), 1, pack);
+
         mapped = false;
         for (c = 0; c < pages; c++) {
                 bool new_mapped = !!(vec[c] & 1);
@@ -479,13 +486,14 @@ done:
                 goto finish;
         }
 
-        if (!(pack = fopen(pack_fn_new, "we"))) {
+        pack = fopen(pack_fn_new, "we");
+        if (!pack) {
                 log_error("Failed to open pack file: %m");
                 r = -errno;
                 goto finish;
         }
 
-        fputs(CANONICAL_HOST "\n", pack);
+        fputs(CANONICAL_HOST ";VERSION=2\n", pack);
         putc(on_ssd ? 'S' : 'R', pack);
 
         if (on_ssd || on_btrfs) {
-- 
cgit v1.2.3-54-g00ecf