Revamp file locking
Get rid of the semaphore implementation, no need to carry both.
Add different locking modes (exclusive and readwrite) to enable
a wider range of testing. Also combine lockfile and lockfile_batch,
the latter is now a postfix option to the former.
So to enable readers-excluding-writers locking mode with a lock batch
count of 4, you would write:
lockfile=readwrite:4
instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/filesetup.c b/filesetup.c
index 4e2a36c..4d2017d 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -226,9 +226,33 @@
return ret;
}
-int generic_open_file(struct thread_data *td, struct fio_file *f)
+static int file_lookup_open(struct fio_file *f, int flags)
{
struct fio_file *__f;
+ int from_hash;
+
+ __f = lookup_file_hash(f->file_name);
+ if (__f) {
+ /*
+ * racy, need the __f->lock locked
+ */
+ f->lock = __f->lock;
+ f->lock_owner = __f->lock_owner;
+ f->lock_batch = __f->lock_batch;
+ f->lock_ddir = __f->lock_ddir;
+ f->fd = dup(__f->fd);
+ f->references++;
+ from_hash = 1;
+ } else {
+ f->fd = open(f->file_name, flags, 0600);
+ from_hash = 0;
+ }
+
+ return from_hash;
+}
+
+int generic_open_file(struct thread_data *td, struct fio_file *f)
+{
int is_std = 0;
int flags = 0;
int from_hash = 0;
@@ -267,16 +291,8 @@
if (is_std)
f->fd = dup(STDOUT_FILENO);
- else {
- __f = lookup_file_hash(f->file_name);
- if (__f) {
- f->sem = __f->sem;
- f->fd = dup(__f->fd);
- f->references++;
- from_hash = 1;
- } else
- f->fd = open(f->file_name, flags, 0600);
- }
+ else
+ from_hash = file_lookup_open(f, flags);
} else {
if (f->filetype == FIO_TYPE_CHAR && !read_only)
flags |= O_RDWR;
@@ -285,16 +301,8 @@
if (is_std)
f->fd = dup(STDIN_FILENO);
- else {
- __f = lookup_file_hash(f->file_name);
- if (__f) {
- f->sem = __f->sem;
- f->fd = dup(__f->fd);
- f->references++;
- from_hash = 1;
- } else
- f->fd = open(f->file_name, flags);
- }
+ else
+ from_hash = file_lookup_open(f, flags);
}
if (f->fd == -1) {
@@ -641,8 +649,19 @@
get_file_type(f);
- if (td->o.lockfile)
- f->sem = fio_sem_init(1);
+ switch (td->o.file_lock_mode) {
+ case FILE_LOCK_NONE:
+ break;
+ case FILE_LOCK_READWRITE:
+ f->lock = fio_mutex_rw_init();
+ break;
+ case FILE_LOCK_EXCLUSIVE:
+ f->lock = fio_mutex_init(1);
+ break;
+ default:
+ log_err("fio: unknown lock mode: %d\n", td->o.file_lock_mode);
+ assert(0);
+ }
td->files_index++;
if (f->filetype == FIO_TYPE_FILE)
@@ -682,31 +701,62 @@
return ret;
}
-void lock_file(struct thread_data *td, struct fio_file *f)
+void lock_file(struct thread_data *td, struct fio_file *f, enum fio_ddir ddir)
{
- if (f && f->sem) {
- if (f->sem_owner == td && f->sem_batch--)
- return;
+ if (!f->lock || td->o.file_lock_mode == FILE_LOCK_NONE)
+ return;
- fio_sem_down(f->sem);
- f->sem_owner = td;
- f->sem_batch = td->o.lockfile_batch;
+ if (f->lock_owner == td && f->lock_batch--)
+ return;
+
+ if (td->o.file_lock_mode == FILE_LOCK_READWRITE) {
+ if (ddir == DDIR_READ)
+ fio_mutex_down_read(f->lock);
+ else
+ fio_mutex_down_write(f->lock);
+ } else if (td->o.file_lock_mode == FILE_LOCK_EXCLUSIVE)
+ fio_mutex_down(f->lock);
+
+ f->lock_owner = td;
+ f->lock_batch = td->o.lockfile_batch;
+ f->lock_ddir = ddir;
+}
+
+void unlock_file(struct thread_data *td, struct fio_file *f)
+{
+ if (!f->lock || td->o.file_lock_mode == FILE_LOCK_NONE)
+ return;
+ if (f->lock_batch)
+ return;
+
+ if (td->o.file_lock_mode == FILE_LOCK_READWRITE) {
+ const int is_read = f->lock_ddir == DDIR_READ;
+ int val = fio_mutex_getval(f->lock);
+
+ if ((is_read && val == 1) || (!is_read && val == -1))
+ f->lock_owner = NULL;
+
+ if (is_read)
+ fio_mutex_up_read(f->lock);
+ else
+ fio_mutex_up_write(f->lock);
+ } else if (td->o.file_lock_mode == FILE_LOCK_EXCLUSIVE) {
+ int val = fio_mutex_getval(f->lock);
+
+ if (val == 0)
+ f->lock_owner = NULL;
+
+ fio_mutex_up(f->lock);
}
}
-void unlock_file(struct fio_file *f)
+void unlock_file_all(struct thread_data *td, struct fio_file *f)
{
- if (f && f->sem) {
- int sem_val;
+ if (f->lock_owner != td)
+ return;
- if (f->sem_batch)
- return;
-
- sem_getvalue(&f->sem->sem, &sem_val);
- if (!sem_val)
- f->sem_owner = NULL;
- fio_sem_up(f->sem);
- }
+ f->lock_batch = 0;
+ unlock_file(td, f);
}
static int recurse_dir(struct thread_data *td, const char *dirname)