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--- mpd-0.18.5.orig/src/db/SimpleDatabasePlugin.cxx 2013-11-22 00:33:30.000000000 +0100
+++ mpd-0.18.5/src/db/SimpleDatabasePlugin.cxx 2013-11-30 19:17:55.000000000 +0100
@@ -35,6 +35,9 @@
#include <sys/types.h>
#include <errno.h>
+#include <sys/mount.h>
+#include <mntent.h>
+#include <string.h>
static constexpr Domain simple_db_domain("simple_db");
@@ -95,8 +98,8 @@ SimpleDatabase::Check(Error &error) cons
return false;
}
- /* Check if we can write to the directory */
- if (!CheckAccess(dirPath, X_OK | W_OK)) {
+ /* Check if we can change into the directory */
+ if (!CheckAccess(dirPath, X_OK)) {
const int e = errno;
const std::string dirPath_utf8 = dirPath.ToUTF8();
error.FormatErrno(e, "Can't create db file in \"%s\"",
@@ -122,9 +125,9 @@ SimpleDatabase::Check(Error &error) cons
return false;
}
- /* And check that we can write to it */
- if (!CheckAccess(path, R_OK | W_OK)) {
- error.FormatErrno("Can't open db file \"%s\" for reading/writing",
+ /* And check that we can read it */
+ if (!CheckAccess(path, R_OK)) {
+ error.FormatErrno("Can't open db file \"%s\" for reading",
path_utf8.c_str());
return false;
}
@@ -281,6 +284,10 @@ SimpleDatabase::GetStats(const DatabaseS
bool
SimpleDatabase::Save(Error &error)
{
+ struct mntent *mnt;
+ int remount;
+ FILE *f;
+
db_lock();
LogDebug(simple_db_domain, "removing empty directories from DB");
@@ -293,6 +300,26 @@ SimpleDatabase::Save(Error &error)
LogDebug(simple_db_domain, "writing DB");
+ remount = 0;
+ /* check if /data is mounted read-only */
+ if ((f = setmntent("/proc/mounts", "r")) == NULL)
+ error.Format(simple_db_domain, "Checking /proc/mounts failed");
+
+ while ((mnt = getmntent(f)) != NULL) {
+ if (strcmp(mnt->mnt_dir, "/data") == 0 &&
+ hasmntopt(mnt, MNTOPT_RO) != NULL) {
+ remount = 1;
+ }
+ }
+ endmntent(f);
+
+ if (remount) {
+ if (mount("","/data",0,MS_REMOUNT,0)<0) {
+ error.Format(simple_db_domain, "Remounting /data rw failed");
+ }
+ LogDebug(simple_db_domain, "Mounted /data successfully in read-write mode");
+ }
+
FILE *fp = FOpen(path, FOpenMode::WriteText);
if (!fp) {
error.FormatErrno("unable to write to db file \"%s\"",
@@ -310,6 +337,16 @@ SimpleDatabase::Save(Error &error)
fclose(fp);
+ if (remount) {
+ sync();
+ if (mount("","/data",0,MS_REMOUNT|MS_RDONLY,0)<0) {
+ error.Format(simple_db_domain, "Remounting /data ro failed");
+ }
+ LogDebug(simple_db_domain, "Mounted /data successfully in read-only mode");
+ }
+
+ LogDebug(simple_db_domain, "Successfully written database");
+
struct stat st;
if (StatFile(path, st))
mtime = st.st_mtime;
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