[PATCH] ide-disk.c: write cache handling fixes

From: Alan Cox <alan@redhat.com>, Arjan van de Ven <arjanv@redhat.com>

 - calculate drive->wcache for non-removable disks too
 - flush the cache before unlocking the door on removable media,
   otherwise you have a small race with the human

diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index b3d7a002afba09d889c8c7d38222b4a03632cc6a..51d7465cba1ed8a54e123005b2bc686456b846e2 100644 (file)
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -1729,11 +1729,11 @@ static ide_driver_t idedisk_driver = {
 
 static int idedisk_open(struct inode *inode, struct file *filp)
 {
+       u8 cf;
        ide_drive_t *drive = inode->i_bdev->bd_disk->private_data;
        drive->usage++;
        if (drive->removable && drive->usage == 1) {
                ide_task_t args;
-               u8 cf;
                memset(&args, 0, sizeof(ide_task_t));
                args.tfRegister[IDE_COMMAND_OFFSET] = WIN_DOORLOCK;
                args.command_type = IDE_DRIVE_TASK_NO_DATA;
@@ -1746,18 +1746,18 @@ static int idedisk_open(struct inode *inode, struct file *filp)
                 */
                if (drive->doorlocking && ide_raw_taskfile(drive, &args, NULL))
                        drive->doorlocking = 0;
-               drive->wcache = 0;
-               /* Cache enabled ? */
-               if (drive->id->csfo & 1)
-               drive->wcache = 1;
-               /* Cache command set available ? */
-               if (drive->id->cfs_enable_1 & (1<<5))
-                       drive->wcache = 1;
-               /* ATA6 cache extended commands */
-               cf = drive->id->command_set_2 >> 24;
-               if((cf & 0xC0) == 0x40 && (cf & 0x30) != 0)
-                       drive->wcache = 1;
        }
+       drive->wcache = 0;
+       /* Cache enabled? */
+       if (drive->id->csfo & 1)
+               drive->wcache = 1;
+       /* Cache command set available? */
+       if (drive->id->cfs_enable_1 & (1 << 5))
+               drive->wcache = 1;
+       /* ATA6 cache extended commands */
+       cf = drive->id->command_set_2 >> 24;
+       if ((cf & 0xC0) == 0x40 && (cf & 0x30) != 0)
+               drive->wcache = 1;
        return 0;
 }
 
@@ -1779,6 +1779,7 @@ static int ide_cacheflush_p(ide_drive_t *drive)
 static int idedisk_release(struct inode *inode, struct file *filp)
 {
        ide_drive_t *drive = inode->i_bdev->bd_disk->private_data;
+       ide_cacheflush_p(drive);
        if (drive->removable && drive->usage == 1) {
                ide_task_t args;
                memset(&args, 0, sizeof(ide_task_t));
@@ -1788,7 +1789,6 @@ static int idedisk_release(struct inode *inode, struct file *filp)
                if (drive->doorlocking && ide_raw_taskfile(drive, &args, NULL))
                        drive->doorlocking = 0;
        }
-       ide_cacheflush_p(drive);
        drive->usage--;
        return 0;
 }