Add the file sharing bits

When you use the same filename for several jobs now, they will share
the same file structure. Enable locking through two new options:

- lockfile. If set, a semaphore is associated with the file and it is
  held from ->prep() to ->queue() has done its work.
- lockfile_batch. This controls how many IOs the job gets to do per
  semaphore acqusition.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index d8c6b9414eef85be48779d7018682cf2bbd07470..3e0a31b6767aadb1855471337b50bd8643767c59 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -219,6 +219,14 @@ filename=str       Fio normally makes up a filename based on the job name,
 opendir=str    Tell fio to recursively add any file it can find in this
                directory and down the file system tree.
 
 opendir=str    Tell fio to recursively add any file it can find in this
                directory and down the file system tree.
 

+lockfile=bool  If set, fio will lock a file internally before doing IO to it.
+               This makes it safe to share file descriptors across fio
+               jobs that run at the same time.
+
+lockfile_batch=int     Acquiring a semaphore can be quite expensive, so
+               allow a process to complete this number of IOs before releasing
+               the semaphore again. Defaults to 1.
+

 readwrite=str
 rw=str         Type of io pattern. Accepted values are:
 
 readwrite=str
 rw=str         Type of io pattern. Accepted values are:
 

diff --git a/filesetup.c b/filesetup.c
index e2c71cd05784f40b294757969c0d57dd73b4cb42..4e2a36cd9debb6968302cd54bd117b967a6b78da 100644 (file)
--- a/filesetup.c
+++ b/filesetup.c
@@ -228,8 +228,10 @@ int generic_close_file(struct thread_data fio_unused *td, struct fio_file *f)
 
 int generic_open_file(struct thread_data *td, struct fio_file *f)
 {
 
 int generic_open_file(struct thread_data *td, struct fio_file *f)
 {

+       struct fio_file *__f;

        int is_std = 0;
        int flags = 0;
        int is_std = 0;
        int flags = 0;

+       int from_hash = 0;

 
        dprint(FD_FILE, "fd open %s\n", f->file_name);
 
 
        dprint(FD_FILE, "fd open %s\n", f->file_name);
 


@@ -265,8 +267,16 @@ open_again:
 
                if (is_std)
                        f->fd = dup(STDOUT_FILENO);
 
                if (is_std)
                        f->fd = dup(STDOUT_FILENO);

-               else
-                       f->fd = open(f->file_name, flags, 0600);
+               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 {
                if (f->filetype == FIO_TYPE_CHAR && !read_only)
                        flags |= O_RDWR;
        } else {
                if (f->filetype == FIO_TYPE_CHAR && !read_only)
                        flags |= O_RDWR;


@@ -275,8 +285,16 @@ open_again:
 
                if (is_std)
                        f->fd = dup(STDIN_FILENO);
 
                if (is_std)
                        f->fd = dup(STDIN_FILENO);

-               else
-                       f->fd = open(f->file_name, flags);
+               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);
+               }

        }
 
        if (f->fd == -1) {
        }
 
        if (f->fd == -1) {


@@ -296,7 +314,17 @@ open_again:
        if (get_file_size(td, f))
                goto err;
 
        if (get_file_size(td, f))
                goto err;
 

-       add_file_hash(f);
+       if (!from_hash && f->fd != -1) {
+               if (add_file_hash(f)) {
+                       int ret;
+
+                       /*
+                        * OK to ignore, we haven't done anything with it
+                        */
+                       ret = generic_close_file(td, f);
+                       goto open_again;
+               }
+       }

 
        return 0;
 err:
 
        return 0;
 err:


@@ -613,6 +641,9 @@ int add_file(struct thread_data *td, const char *fname)
 
        get_file_type(f);
 
 
        get_file_type(f);
 

+       if (td->o.lockfile)
+               f->sem = fio_sem_init(1);
+

        td->files_index++;
        if (f->filetype == FIO_TYPE_FILE)
                td->nr_normal_files++;
        td->files_index++;
        if (f->filetype == FIO_TYPE_FILE)
                td->nr_normal_files++;


@@ -653,10 +684,29 @@ int put_file(struct thread_data *td, struct fio_file *f)
 
 void lock_file(struct thread_data *td, struct fio_file *f)
 {
 
 void lock_file(struct thread_data *td, struct fio_file *f)
 {

+       if (f && f->sem) {
+               if (f->sem_owner == td && f->sem_batch--)
+                       return;
+
+               fio_sem_down(f->sem);
+               f->sem_owner = td;
+               f->sem_batch = td->o.lockfile_batch;
+       }

 }
 
 void unlock_file(struct fio_file *f)
 {
 }
 
 void unlock_file(struct fio_file *f)
 {

+       if (f && f->sem) {
+               int sem_val;
+
+               if (f->sem_batch)
+                       return;
+
+               sem_getvalue(&f->sem->sem, &sem_val);
+               if (!sem_val)
+                       f->sem_owner = NULL;
+               fio_sem_up(f->sem);
+       }

 }
 
 static int recurse_dir(struct thread_data *td, const char *dirname)
 }
 
 static int recurse_dir(struct thread_data *td, const char *dirname)

diff --git a/fio.h b/fio.h
index fe1a227d317649f52398565881edbce715e7c998..ffd3d7d00a1252cc60ca1280269977a7f1f2b36e 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -22,6 +22,7 @@
 #include "arch/arch.h"
 #include "os/os.h"
 #include "mutex.h"
 #include "arch/arch.h"
 #include "os/os.h"
 #include "mutex.h"

+#include "sem.h"

 #include "log.h"
 #include "debug.h"
 
 #include "log.h"
 #include "debug.h"
 


@@ -309,6 +310,13 @@ struct fio_file {
 
        unsigned long long last_pos;
 
 
        unsigned long long last_pos;
 

+       /*
+        * if io is protected by a semaphore, this is set
+        */
+       struct fio_sem *sem;
+       void *sem_owner;
+       unsigned int sem_batch;
+

        /*
         * block map for random io
         */
        /*
         * block map for random io
         */


@@ -407,6 +415,8 @@ struct thread_options {
 
        unsigned int nr_files;
        unsigned int open_files;
 
        unsigned int nr_files;
        unsigned int open_files;

+       unsigned int lockfile;
+       unsigned int lockfile_batch;

 
        unsigned int odirect;
        unsigned int invalidate_cache;
 
        unsigned int odirect;
        unsigned int invalidate_cache;

diff --git a/ioengines.c b/ioengines.c
index 5a2d6b90fb0c6d73d45d0b6c5ce5307f505691d2..bd2eb4a71ed899f2b7d3857d97ce87312b05aa2e 100644 (file)
--- a/ioengines.c
+++ b/ioengines.c
@@ -359,5 +359,10 @@ int td_io_close_file(struct thread_data *td, struct fio_file *f)
         */
        f->flags |= FIO_FILE_CLOSING;
 
         */
        f->flags |= FIO_FILE_CLOSING;
 

+       if (f->sem_owner == td && f->sem_batch) {
+               f->sem_batch = 0;
+               unlock_file(f);
+       }
+

        return put_file(td, f);
 }
        return put_file(td, f);
 }

diff --git a/options.c b/options.c
index 1119a9806346219958ca512573f9ac4f25ca08d0..27b4fb65eb1b6158763050badd5821db122f089d 100644 (file)
--- a/options.c
+++ b/options.c
@@ -384,6 +384,22 @@ static struct fio_option options[] = {
                .cb     = str_filename_cb,
                .help   = "File(s) to use for the workload",
        },
                .cb     = str_filename_cb,
                .help   = "File(s) to use for the workload",
        },

+       {
+               .name   = "lockfile",
+               .type   = FIO_OPT_BOOL,
+               .off1   = td_var_offset(lockfile),
+               .help   = "Lock file when doing IO to it",
+               .parent = "filename",
+               .def    = "0",
+       },
+       {
+               .name   = "lockfile_batch",
+               .type   = FIO_OPT_INT,
+               .off1   = td_var_offset(lockfile_batch),
+               .help   = "Number of IOs to allow per file lock",
+               .parent = "lockfile",
+               .def    = "1",
+       },

        {
                .name   = "opendir",
                .type   = FIO_OPT_STR_STORE,
        {
                .name   = "opendir",
                .type   = FIO_OPT_STR_STORE,