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-rw-r--r--shlibs/mount/src/context.c25
-rw-r--r--shlibs/mount/src/lock.c5
-rw-r--r--shlibs/mount/src/tab_update.c104
3 files changed, 32 insertions, 102 deletions
diff --git a/shlibs/mount/src/context.c b/shlibs/mount/src/context.c
index eedb82345..1968a4b34 100644
--- a/shlibs/mount/src/context.c
+++ b/shlibs/mount/src/context.c
@@ -798,8 +798,9 @@ struct libmnt_cache *mnt_context_get_cache(struct libmnt_context *cxt)
* small exception: the application has to be able to remove the lock file when
* interrupted by signal or signals have to be ignored when the lock is locked.
*
- * The default behavior is to ignore all signals (except SIGALRM and SIGTRAP)
- * when the lock is locked. If this behavior is unacceptable then use:
+ * The default behavior is to ignore all signals (except SIGALRM and
+ * SIGTRAP for mtab udate) when the lock is locked. If this behavior
+ * is unacceptable then use:
*
* lc = mnt_context_get_lock(cxt);
* if (lc)
@@ -807,18 +808,21 @@ struct libmnt_cache *mnt_context_get_cache(struct libmnt_context *cxt)
*
* and don't forget to call mnt_unlock_file(lc) before exit.
*
- * This function returns NULL if the lock is unnecessary (mtab file is not writable
- * or /etc/mtab is symlink to /proc/mounts).
- *
* Returns: pointer to lock struct or NULL.
*/
struct libmnt_lock *mnt_context_get_lock(struct libmnt_context *cxt)
{
- if (!cxt || (cxt->flags & MNT_FL_NOMTAB) || !cxt->mtab_writable)
+ /*
+ * DON'T call this function within libmount, it will always allocate
+ * the lock. The mnt_update_* functions are able to allocate the lock
+ * only when mtab/utab update is really necessary.
+ */
+ if (!cxt || (cxt->flags & MNT_FL_NOMTAB))
return NULL;
- if (!cxt->lock && cxt->mtab_path) {
- cxt->lock = mnt_new_lock(cxt->mtab_path, 0);
+ if (!cxt->lock) {
+ cxt->lock = mnt_new_lock(cxt->mtab_writable ?
+ cxt->mtab_path : cxt->utab_path, 0);
if (cxt->lock)
mnt_lock_block_signals(cxt->lock, TRUE);
}
@@ -1323,7 +1327,7 @@ int mnt_context_update_tabs(struct libmnt_context *cxt)
mnt_update_force_rdonly(cxt->update,
cxt->mountflags & MS_RDONLY);
- return mnt_update_table(cxt->update, mnt_context_get_lock(cxt));
+ return mnt_update_table(cxt->update, cxt->lock);
}
static int apply_table(struct libmnt_context *cxt, struct libmnt_table *tb,
@@ -1610,6 +1614,9 @@ int test_mount(struct libmnt_test *ts, int argc, char *argv[])
mnt_context_set_target(cxt, argv[idx++]);
}
+ /* this is unnecessary -- libmount is able to internaly
+ * create and manage the lock
+ */
lock = mnt_context_get_lock(cxt);
if (lock)
atexit(lock_fallback);
diff --git a/shlibs/mount/src/lock.c b/shlibs/mount/src/lock.c
index daf204496..53c1115ec 100644
--- a/shlibs/mount/src/lock.c
+++ b/shlibs/mount/src/lock.c
@@ -88,7 +88,7 @@ struct libmnt_lock *mnt_new_lock(const char *datafile, pid_t id)
ml->linkfile = ln;
ml->lockfile = lo;
- DBG(LOCKS, mnt_debug_h(ml, "alloc: linkfile=%s, lockfile=%s", ln, lo));
+ DBG(LOCKS, mnt_debug_h(ml, "alloc: default linkfile=%s, lockfile=%s", ln, lo));
return ml;
err:
free(lo);
@@ -160,7 +160,7 @@ int mnt_lock_use_simplelock(struct libmnt_lock *ml, int enable)
else if (!ml->simplelock && endswith(ml->lockfile, ".lock"))
memcpy(ml->lockfile + sz - 5, "~", 2);
- DBG(LOCKS, mnt_debug_h(ml, "lock filename: '%s'", ml->lockfile));
+ DBG(LOCKS, mnt_debug_h(ml, "new lock filename: '%s'", ml->lockfile));
return 0;
}
@@ -234,6 +234,7 @@ static int lock_simplelock(struct libmnt_lock *ml)
rc = -errsv;
goto err;
}
+ ml->locked = 1;
return 0;
err:
if (ml->sigblock)
diff --git a/shlibs/mount/src/tab_update.c b/shlibs/mount/src/tab_update.c
index 4822dffc5..d51464184 100644
--- a/shlibs/mount/src/tab_update.c
+++ b/shlibs/mount/src/tab_update.c
@@ -41,9 +41,6 @@ struct libmnt_update {
unsigned long mountflags;
int userspace_only;
int ready;
-
- sigset_t oldsigmask;
- int utab_lock;
};
static int utab_new_entry(struct libmnt_fs *fs, unsigned long mountflags, struct libmnt_fs **ent);
@@ -62,7 +59,6 @@ struct libmnt_update *mnt_new_update(void)
if (!upd)
return NULL;
- upd->utab_lock = -1;
DBG(UPDATE, mnt_debug_h(upd, "allocate"));
return upd;
}
@@ -132,14 +128,13 @@ int mnt_update_set_filename(struct libmnt_update *upd, const char *filename,
* mnt_update_get_filename:
* @upd: update
*
- * This function returns file name (e.g. /etc/mtab) if the update
- * should be covered by mnt_lock, otherwise returne NULL.
+ * This function returns file name (e.g. /etc/mtab) for the up-dated file.
*
* Returns: pointer to filename that will be updated or NULL in case of error.
*/
const char *mnt_update_get_filename(struct libmnt_update *upd)
{
- return upd && !upd->userspace_only ? upd->filename : NULL;
+ return upd ? upd->filename : NULL;
}
/**
@@ -634,63 +629,6 @@ leave:
return rc;
}
-static int utab_lock(struct libmnt_update *upd)
-{
- char *lfile;
- int rc;
- sigset_t sigs;
-
- assert(upd);
- assert(upd->filename);
- assert(upd->userspace_only);
-
- if (asprintf(&lfile, "%s.lock", upd->filename) == -1)
- return -1;
-
- DBG(UPDATE, mnt_debug("%s: locking", lfile));
-
- sigemptyset(&upd->oldsigmask);
- sigfillset(&sigs);
- sigprocmask(SIG_BLOCK, &sigs, &upd->oldsigmask);
-
- upd->utab_lock = open(lfile, O_RDONLY|O_CREAT|O_CLOEXEC, S_IWUSR|
- S_IRUSR|S_IRGRP|S_IROTH);
- free(lfile);
-
- if (upd->utab_lock < 0) {
- rc = -errno;
- goto err;
- }
-
- while (flock(upd->utab_lock, LOCK_EX) < 0) {
- int errsv;
- if ((errno == EAGAIN) || (errno == EINTR))
- continue;
- errsv = errno;
- close(upd->utab_lock);
- upd->utab_lock = -1;
- rc = -errsv;
- goto err;
- }
- return 0;
-err:
- sigprocmask(SIG_SETMASK, &upd->oldsigmask, NULL);
- return rc;
-}
-
-static void utab_unlock(struct libmnt_update *upd)
-{
- assert(upd);
- assert(upd->userspace_only);
-
- if (upd->utab_lock >= 0) {
- DBG(UPDATE, mnt_debug("unlocking utab"));
- close(upd->utab_lock);
- upd->utab_lock = -1;
- sigprocmask(SIG_SETMASK, &upd->oldsigmask, NULL);
- }
-}
-
static int update_add_entry(struct libmnt_update *upd, struct libmnt_lock *lc)
{
struct libmnt_table *tb;
@@ -701,9 +639,7 @@ static int update_add_entry(struct libmnt_update *upd, struct libmnt_lock *lc)
DBG(UPDATE, mnt_debug_h(upd, "%s: add entry", upd->filename));
- if (upd->userspace_only)
- rc = utab_lock(upd);
- else if (lc)
+ if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
@@ -720,9 +656,7 @@ static int update_add_entry(struct libmnt_update *upd, struct libmnt_lock *lc)
}
}
- if (upd->userspace_only)
- utab_unlock(upd);
- else if (lc)
+ if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
@@ -739,9 +673,7 @@ static int update_remove_entry(struct libmnt_update *upd, struct libmnt_lock *lc
DBG(UPDATE, mnt_debug_h(upd, "%s: remove entry", upd->filename));
- if (upd->userspace_only)
- rc = utab_lock(upd);
- else if (lc)
+ if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
@@ -757,9 +689,7 @@ static int update_remove_entry(struct libmnt_update *upd, struct libmnt_lock *lc
}
}
- if (upd->userspace_only)
- utab_unlock(upd);
- else if (lc)
+ if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
@@ -773,9 +703,7 @@ static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *l
DBG(UPDATE, mnt_debug_h(upd, "%s: modify target", upd->filename));
- if (upd->userspace_only)
- rc = utab_lock(upd);
- else if (lc)
+ if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
@@ -792,9 +720,7 @@ static int update_modify_target(struct libmnt_update *upd, struct libmnt_lock *l
}
}
- if (upd->userspace_only)
- utab_unlock(upd);
- else if (lc)
+ if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
@@ -814,9 +740,7 @@ static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock *
fs = upd->fs;
- if (upd->userspace_only)
- rc = utab_lock(upd);
- else if (lc)
+ if (lc)
rc = mnt_lock_file(lc);
if (rc)
return rc;
@@ -837,9 +761,7 @@ static int update_modify_options(struct libmnt_update *upd, struct libmnt_lock *
}
}
- if (upd->userspace_only)
- utab_unlock(upd);
- else if (lc)
+ if (lc)
mnt_unlock_file(lc);
mnt_free_table(tb);
@@ -876,11 +798,13 @@ int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc)
if (upd->fs) {
DBG(UPDATE, mnt_fs_print_debug(upd->fs, stderr));
}
- if (!lc && !upd->userspace_only) {
+ if (!lc) {
lc = mnt_new_lock(upd->filename, 0);
if (lc)
mnt_lock_block_signals(lc, TRUE);
}
+ if (lc && upd->userspace_only)
+ mnt_lock_use_simplelock(lc, TRUE); /* use flock */
if (!upd->fs && upd->target)
rc = update_remove_entry(upd, lc); /* umount */
@@ -894,10 +818,8 @@ int mnt_update_table(struct libmnt_update *upd, struct libmnt_lock *lc)
upd->ready = FALSE;
DBG(UPDATE, mnt_debug_h(upd, "%s: update tab: done [rc=%d]",
upd->filename, rc));
-
if (lc != lc0)
mnt_free_lock(lc);
-
return rc;
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-15 22:20:14 +0200