qlge: bugfix: Move netif_napi_del() to common call point.

[safe/jmp/linux-2.6] / drivers / block / loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3f09cd8..edbaac6 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -40,8 +40,7 @@
  * Heinz Mauelshagen <mge@sistina.com>, Feb 2002
  *
  * Support for falling back on the write file operation when the address space
- * operations prepare_write and/or commit_write are not available on the
- * backing filesystem.
+ * operations write_begin is not available on the backing filesystem.
  * Anton Altaparmakov, 16 Feb 2005
  *
  * Still To Fix:
@@ -625,20 +624,38 @@ static int loop_switch(struct loop_device *lo, struct file *file)
 }
 
 /*
+ * Helper to flush the IOs in loop, but keeping loop thread running
+ */
+static int loop_flush(struct loop_device *lo)
+{
+       /* loop not yet configured, no running thread, nothing to flush */
+       if (!lo->lo_thread)
+               return 0;
+
+       return loop_switch(lo, NULL);
+}
+
+/*
  * Do the actual switch; called from the BIO completion routine
  */
 static void do_loop_switch(struct loop_device *lo, struct switch_request *p)
 {
        struct file *file = p->file;
        struct file *old_file = lo->lo_backing_file;
-       struct address_space *mapping = file->f_mapping;
+       struct address_space *mapping;
+
+       /* if no new file, only flush of queued bios requested */
+       if (!file)
+               goto out;
 
+       mapping = file->f_mapping;
        mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
        lo->lo_backing_file = file;
        lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ?
                mapping->host->i_bdev->bd_block_size : PAGE_SIZE;
        lo->old_gfp_mask = mapping_gfp_mask(mapping);
        mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
+out:
        complete(&p->wait);
 }
 
@@ -765,7 +782,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
                 */
                if (!file->f_op->splice_read)
                        goto out_putf;
-               if (aops->prepare_write || aops->write_begin)
+               if (aops->write_begin)
                        lo_flags |= LO_FLAGS_USE_AOPS;
                if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write)
                        lo_flags |= LO_FLAGS_READ_ONLY;
@@ -902,6 +919,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
 
        kthread_stop(lo->lo_thread);
 
+       lo->lo_queue->unplug_fn = NULL;
        lo->lo_backing_file = NULL;
 
        loop_release_xfer(lo);
@@ -937,8 +955,10 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 {
        int err;
        struct loop_func_table *xfer;
+       uid_t uid = current_uid();
 
-       if (lo->lo_encrypt_key_size && lo->lo_key_owner != current->uid &&
+       if (lo->lo_encrypt_key_size &&
+           lo->lo_key_owner != uid &&
            !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (lo->lo_state != Lo_bound)
@@ -993,7 +1013,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
        if (info->lo_encrypt_key_size) {
                memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
                       info->lo_encrypt_key_size);
-               lo->lo_key_owner = current->uid;
+               lo->lo_key_owner = uid;
        }       
 
        return 0;
@@ -1344,11 +1364,25 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
        struct loop_device *lo = disk->private_data;
 
        mutex_lock(&lo->lo_ctl_mutex);
-       --lo->lo_refcnt;
 
-       if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) && !lo->lo_refcnt)
+       if (--lo->lo_refcnt)
+               goto out;
+
+       if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
+               /*
+                * In autoclear mode, stop the loop thread
+                * and remove configuration after last close.
+                */
                loop_clr_fd(lo, NULL);
+       } else {
+               /*
+                * Otherwise keep thread (if running) and config,
+                * but flush possible ongoing bios in thread.
+                */
+               loop_flush(lo);
+       }
 
+out:
        mutex_unlock(&lo->lo_ctl_mutex);
 
        return 0;