Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / drivers / target / target_core_file.c

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 455a251..ea29eaf 100644 (file)
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -139,6 +139,19 @@ static struct se_device *fd_create_virtdevice(
         * of pure timestamp updates.
         */
        flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
+       /*
+        * Optionally allow fd_buffered_io=1 to be enabled for people
+        * who want use the fs buffer cache as an WriteCache mechanism.
+        *
+        * This means that in event of a hard failure, there is a risk
+        * of silent data-loss if the SCSI client has *not* performed a
+        * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
+        * to write-out the entire device cache.
+        */
+       if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
+               pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
+               flags &= ~O_DSYNC;
+       }
 
        file = filp_open(dev_p, flags, 0600);
        if (IS_ERR(file)) {
@@ -206,6 +219,12 @@ static struct se_device *fd_create_virtdevice(
        if (!dev)
                goto fail;
 
+       if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
+               pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
+                       " with FDBD_HAS_BUFFERED_IO_WCE\n");
+               dev->se_sub_dev->se_dev_attrib.emulate_write_cache = 1;
+       }
+
        fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
        fd_dev->fd_queue_depth = dev->queue_depth;
 
@@ -281,7 +300,7 @@ static int fd_do_readv(struct se_task *task)
 
        for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
                iov[i].iov_len = sg->length;
-               iov[i].iov_base = sg_virt(sg);
+               iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
        }
 
        old_fs = get_fs();
@@ -289,6 +308,8 @@ static int fd_do_readv(struct se_task *task)
        ret = vfs_readv(fd, &iov[0], task->task_sg_nents, &pos);
        set_fs(old_fs);
 
+       for_each_sg(task->task_sg, sg, task->task_sg_nents, i)
+               kunmap(sg_page(sg));
        kfree(iov);
        /*
         * Return zeros and GOOD status even if the READ did not return
@@ -334,7 +355,7 @@ static int fd_do_writev(struct se_task *task)
 
        for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
                iov[i].iov_len = sg->length;
-               iov[i].iov_base = sg_virt(sg);
+               iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
        }
 
        old_fs = get_fs();
@@ -342,6 +363,9 @@ static int fd_do_writev(struct se_task *task)
        ret = vfs_writev(fd, &iov[0], task->task_sg_nents, &pos);
        set_fs(old_fs);
 
+       for_each_sg(task->task_sg, sg, task->task_sg_nents, i)
+               kunmap(sg_page(sg));
+
        kfree(iov);
 
        if (ret < 0 || ret != task->task_size) {
@@ -450,6 +474,7 @@ enum {
 static match_table_t tokens = {
        {Opt_fd_dev_name, "fd_dev_name=%s"},
        {Opt_fd_dev_size, "fd_dev_size=%s"},
+       {Opt_fd_buffered_io, "fd_buffered_io=%d"},
        {Opt_err, NULL}
 };
 
@@ -461,7 +486,7 @@ static ssize_t fd_set_configfs_dev_params(
        struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
        char *orig, *ptr, *arg_p, *opts;
        substring_t args[MAX_OPT_ARGS];
-       int ret = 0, token;
+       int ret = 0, arg, token;
 
        opts = kstrdup(page, GFP_KERNEL);
        if (!opts)
@@ -505,6 +530,19 @@ static ssize_t fd_set_configfs_dev_params(
                                        " bytes\n", fd_dev->fd_dev_size);
                        fd_dev->fbd_flags |= FBDF_HAS_SIZE;
                        break;
+               case Opt_fd_buffered_io:
+                       match_int(args, &arg);
+                       if (arg != 1) {
+                               pr_err("bogus fd_buffered_io=%d value\n", arg);
+                               ret = -EINVAL;
+                               goto out;
+                       }
+
+                       pr_debug("FILEIO: Using buffered I/O"
+                               " operations for struct fd_dev\n");
+
+                       fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
+                       break;
                default:
                        break;
                }
@@ -536,8 +574,10 @@ static ssize_t fd_show_configfs_dev_params(
        ssize_t bl = 0;
 
        bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
-       bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: O_DSYNC\n",
-               fd_dev->fd_dev_name, fd_dev->fd_dev_size);
+       bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
+               fd_dev->fd_dev_name, fd_dev->fd_dev_size,
+               (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
+               "Buffered-WCE" : "O_DSYNC");
        return bl;
 }