X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Freadahead-common.c;h=d76188b71f4c09de305f2a6556059f39b7d98d72;hp=8533717d479ae7aa8befb3b4812aea5b537ec649;hb=1ddff895f3ad85ec79c4923ba8c882a283826f42;hpb=22be093ffb403a1c474037939ca9b88b1ee39f77

diff --git a/src/readahead-common.c b/src/readahead-common.c
index 8533717d4..d76188b71 100644
--- a/src/readahead-common.c
+++ b/src/readahead-common.c
@@ -23,12 +23,17 @@
 #include <libudev.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/sysinfo.h>
+#include <sys/inotify.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
 
 #include "log.h"
 #include "readahead-common.h"
 #include "util.h"
 
-int file_verify(int fd, const char *fn, struct stat *st) {
+int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) {
         assert(fd >= 0);
         assert(fn);
         assert(st);
@@ -43,8 +48,8 @@ int file_verify(int fd, const char *fn, struct stat *st) {
                 return 0;
         }
 
-        if (st->st_size <= 0 || st->st_size > READAHEAD_FILE_SIZE_MAX) {
-                log_debug("Not preloading file %s with size out of bounds %zi", fn, st->st_size);
+        if (st->st_size <= 0 || st->st_size > file_size_max) {
+                log_debug("Not preloading file %s with size out of bounds %llu", fn, (unsigned long long) st->st_size);
                 return 0;
         }
 
@@ -105,3 +110,63 @@ finish:
 
         return b;
 }
+
+bool enough_ram(void) {
+        struct sysinfo si;
+
+        assert_se(sysinfo(&si) >= 0);
+
+        return si.totalram > 127 * 1024*1024; /* Enable readahead only
+                                               * with at least 128MB
+                                               * memory */
+}
+
+int open_inotify(void) {
+        int fd;
+
+        if ((fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
+                log_error("Failed to create inotify handle: %m");
+                return -errno;
+        }
+
+        mkdir("/dev/.systemd", 0755);
+        mkdir("/dev/.systemd/readahead", 0755);
+
+        if (inotify_add_watch(fd, "/dev/.systemd/readahead", IN_CREATE) < 0) {
+                log_error("Failed to watch /dev/.systemd/readahead: %m");
+                close_nointr_nofail(fd);
+                return -errno;
+        }
+
+        return fd;
+}
+
+ReadaheadShared *shared_get(void) {
+        int fd;
+        ReadaheadShared *m = NULL;
+
+        mkdir("/dev/.systemd", 0755);
+        mkdir("/dev/.systemd/readahead", 0755);
+
+        if ((fd = open("/dev/.systemd/readahead/shared", O_CREAT|O_RDWR|O_CLOEXEC, 0644)) < 0) {
+                log_error("Failed to create shared memory segment: %m");
+                goto finish;
+        }
+
+        if (ftruncate(fd, sizeof(ReadaheadShared)) < 0) {
+                log_error("Failed to truncate shared memory segment: %m");
+                goto finish;
+        }
+
+        if ((m = mmap(NULL, sizeof(ReadaheadShared), PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
+                log_error("Failed to mmap shared memory segment: %m");
+                m = NULL;
+                goto finish;
+        }
+
+finish:
+        if (fd >= 0)
+                close_nointr_nofail(fd);
+
+        return m;
+}