ide: add ide_device_{get,put}() helpers

* Add 'struct ide_host *host' field to ide_hwif_t and set it
  in ide_host_alloc_all().

* Add ide_device_{get,put}() helpers loosely based on SCSI's
  scsi_device_{get,put}() ones.

* Convert IDE device drivers to use ide_device_{get,put}().

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 4e73aee..8f253e5 100644 (file)
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -57,23 +57,29 @@ static DEFINE_MUTEX(idecd_ref_mutex);
 #define ide_cd_g(disk) \
        container_of((disk)->private_data, struct cdrom_info, driver)
 
+static void ide_cd_release(struct kref *);
+
 static struct cdrom_info *ide_cd_get(struct gendisk *disk)
 {
        struct cdrom_info *cd = NULL;
 
        mutex_lock(&idecd_ref_mutex);
        cd = ide_cd_g(disk);
-       if (cd)
+       if (cd) {
                kref_get(&cd->kref);
+               if (ide_device_get(cd->drive)) {
+                       kref_put(&cd->kref, ide_cd_release);
+                       cd = NULL;
+               }
+       }
        mutex_unlock(&idecd_ref_mutex);
        return cd;
 }
 
-static void ide_cd_release(struct kref *);
-
 static void ide_cd_put(struct cdrom_info *cd)
 {
        mutex_lock(&idecd_ref_mutex);
+       ide_device_put(cd->drive);
        kref_put(&cd->kref, ide_cd_release);
        mutex_unlock(&idecd_ref_mutex);
 }

diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index df5fe57..28d85b4 100644 (file)
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -56,23 +56,29 @@ static DEFINE_MUTEX(idedisk_ref_mutex);
 #define ide_disk_g(disk) \
        container_of((disk)->private_data, struct ide_disk_obj, driver)
 
+static void ide_disk_release(struct kref *);
+
 static struct ide_disk_obj *ide_disk_get(struct gendisk *disk)
 {
        struct ide_disk_obj *idkp = NULL;
 
        mutex_lock(&idedisk_ref_mutex);
        idkp = ide_disk_g(disk);
-       if (idkp)
+       if (idkp) {
                kref_get(&idkp->kref);
+               if (ide_device_get(idkp->drive)) {
+                       kref_put(&idkp->kref, ide_disk_release);
+                       idkp = NULL;
+               }
+       }
        mutex_unlock(&idedisk_ref_mutex);
        return idkp;
 }
 
-static void ide_disk_release(struct kref *);
-
 static void ide_disk_put(struct ide_disk_obj *idkp)
 {
        mutex_lock(&idedisk_ref_mutex);
+       ide_device_put(idkp->drive);
        kref_put(&idkp->kref, ide_disk_release);
        mutex_unlock(&idedisk_ref_mutex);
 }

diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 3d8e6dd..ca11a26 100644 (file)
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -158,23 +158,29 @@ static DEFINE_MUTEX(idefloppy_ref_mutex);
 #define ide_floppy_g(disk) \
        container_of((disk)->private_data, struct ide_floppy_obj, driver)
 
+static void idefloppy_cleanup_obj(struct kref *);
+
 static struct ide_floppy_obj *ide_floppy_get(struct gendisk *disk)
 {
        struct ide_floppy_obj *floppy = NULL;
 
        mutex_lock(&idefloppy_ref_mutex);
        floppy = ide_floppy_g(disk);
-       if (floppy)
+       if (floppy) {
                kref_get(&floppy->kref);
+               if (ide_device_get(floppy->drive)) {
+                       kref_put(&floppy->kref, idefloppy_cleanup_obj);
+                       floppy = NULL;
+               }
+       }
        mutex_unlock(&idefloppy_ref_mutex);
        return floppy;
 }
 
-static void idefloppy_cleanup_obj(struct kref *);
-
 static void ide_floppy_put(struct ide_floppy_obj *floppy)
 {
        mutex_lock(&idefloppy_ref_mutex);
+       ide_device_put(floppy->drive);
        kref_put(&floppy->kref, idefloppy_cleanup_obj);
        mutex_unlock(&idefloppy_ref_mutex);
 }

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 890c15b..9ab5892 100644 (file)
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1595,6 +1595,8 @@ struct ide_host *ide_host_alloc_all(const struct ide_port_info *d,
 
                ide_init_port_data(hwif, idx);
 
+               hwif->host = host;
+
                host->ports[i] = hwif;
                host->n_ports++;
        }

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 6962ca4..789f342 100644 (file)
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -322,23 +322,29 @@ static struct class *idetape_sysfs_class;
 #define ide_tape_g(disk) \
        container_of((disk)->private_data, struct ide_tape_obj, driver)
 
+static void ide_tape_release(struct kref *);
+
 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 {
        struct ide_tape_obj *tape = NULL;
 
        mutex_lock(&idetape_ref_mutex);
        tape = ide_tape_g(disk);
-       if (tape)
+       if (tape) {
                kref_get(&tape->kref);
+               if (ide_device_get(tape->drive)) {
+                       kref_put(&tape->kref, ide_tape_release);
+                       tape = NULL;
+               }
+       }
        mutex_unlock(&idetape_ref_mutex);
        return tape;
 }
 
-static void ide_tape_release(struct kref *);
-
 static void ide_tape_put(struct ide_tape_obj *tape)
 {
        mutex_lock(&idetape_ref_mutex);
+       ide_device_put(tape->drive);
        kref_put(&tape->kref, ide_tape_release);
        mutex_unlock(&idetape_ref_mutex);
 }

diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 60f0ca6..7724516 100644 (file)
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -618,6 +618,53 @@ set_val:
 
 EXPORT_SYMBOL(generic_ide_ioctl);
 
+/**
+ * ide_device_get      -       get an additional reference to a ide_drive_t
+ * @drive:     device to get a reference to
+ *
+ * Gets a reference to the ide_drive_t and increments the use count of the
+ * underlying LLDD module.
+ */
+int ide_device_get(ide_drive_t *drive)
+{
+       struct device *host_dev;
+       struct module *module;
+
+       if (!get_device(&drive->gendev))
+               return -ENXIO;
+
+       host_dev = drive->hwif->host->dev[0];
+       module = host_dev ? host_dev->driver->owner : NULL;
+
+       if (module && !try_module_get(module)) {
+               put_device(&drive->gendev);
+               return -ENXIO;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ide_device_get);
+
+/**
+ * ide_device_put      -       release a reference to a ide_drive_t
+ * @drive:     device to release a reference on
+ *
+ * Release a reference to the ide_drive_t and decrements the use count of
+ * the underlying LLDD module.
+ */
+void ide_device_put(ide_drive_t *drive)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+       struct device *host_dev = drive->hwif->host->dev[0];
+       struct module *module = host_dev ? host_dev->driver->owner : NULL;
+
+       if (module)
+               module_put(module);
+#endif
+       put_device(&drive->gendev);
+}
+EXPORT_SYMBOL_GPL(ide_device_put);
+
 static int ide_bus_match(struct device *dev, struct device_driver *drv)
 {
        return 1;

diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 5385524..318ef38 100644 (file)
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -101,8 +101,13 @@ static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk)
 
        mutex_lock(&idescsi_ref_mutex);
        scsi = ide_scsi_g(disk);
-       if (scsi)
+       if (scsi) {
                scsi_host_get(scsi->host);
+               if (ide_device_get(scsi->drive)) {
+                       scsi_host_put(scsi->host);
+                       scsi = NULL;
+               }
+       }
        mutex_unlock(&idescsi_ref_mutex);
        return scsi;
 }
@@ -110,6 +115,7 @@ static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk)
 static void ide_scsi_put(struct ide_scsi_obj *scsi)
 {
        mutex_lock(&idescsi_ref_mutex);
+       ide_device_put(scsi->drive);
        scsi_host_put(scsi->host);
        mutex_unlock(&idescsi_ref_mutex);
 }

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 776c574..3eccac0 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -532,12 +532,16 @@ struct ide_dma_ops {
        void    (*dma_timeout)(struct ide_drive_s *);
 };
 
+struct ide_host;
+
 typedef struct hwif_s {
        struct hwif_s *next;            /* for linked-list in ide_hwgroup_t */
        struct hwif_s *mate;            /* other hwif from same PCI chip */
        struct hwgroup_s *hwgroup;      /* actually (ide_hwgroup_t *) */
        struct proc_dir_entry *proc;    /* /proc/ide/ directory entry */
 
+       struct ide_host *host;
+
        char name[6];                   /* name of interface, eg. "ide0" */
 
        struct ide_io_ports     io_ports;
@@ -876,6 +880,9 @@ struct ide_driver_s {
 
 #define to_ide_driver(drv) container_of(drv, ide_driver_t, gen_driver)
 
+int ide_device_get(ide_drive_t *);
+void ide_device_put(ide_drive_t *);
+
 int generic_ide_ioctl(ide_drive_t *, struct file *, struct block_device *, unsigned, unsigned long);
 
 extern int ide_vlb_clk;