diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 4048db8..6607204 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -122,6 +122,67 @@ static struct device_attribute dev_mtd_num = __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL); /** + * ubi_enum_volumes - "enumerate" volumes. + * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc) + * @ubi: UBI device description object + * @nb: notifier to be called or %NULL to send to system-wide notification + * + * This function walks all volumes of UBI device @ubi and sends the + * notification specified by @ntype. Returns number of sent notifications. + */ +int ubi_enum_volumes(int ntype, struct ubi_device *ubi, + struct notifier_block *nb) +{ + struct ubi_volume_notification nt; + int i, count = 0; + + nt.ubi_num = ubi->ubi_num; + + spin_lock(&ubi->volumes_lock); + for (i = 0; i < ubi->vtbl_slots; i++) { + if (!ubi->volumes[i]) + continue; + nt.vol_id = ubi->volumes[i]->vol_id; + spin_unlock(&ubi->volumes_lock); + if (nb) + nb->notifier_call(nb, ntype, &nt); + else + blocking_notifier_call_chain(&ubi_notifiers, + ntype, &nt); + count++; + spin_lock(&ubi->volumes_lock); + } + spin_unlock(&ubi->volumes_lock); + + return count; +} + +/** + * ubi_enum_all_volumes - enumerate all existing volumes and send notification. + * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc) + * @nb: notifier to be called, or %NULL to send to system-wide notification + * + * This function walks all UBI devices and all volumes on the device, and sends + * the notification specified by @ntype. Returns number of sent notifications. + */ +int ubi_enum_all_volumes(int ntype, struct notifier_block *nb) +{ + struct ubi_device *ubi; + int i, count = 0; + + spin_lock(&ubi_devices_lock); + for (i = 0; i < UBI_MAX_DEVICES; i++) { + ubi = ubi_devices[i]; + spin_unlock(&ubi_devices_lock); + if (ubi) + count += ubi_enum_volumes(ntype, ubi, nb); + spin_lock(&ubi_devices_lock); + } + spin_unlock(&ubi_devices_lock); + return count; +} + +/** * ubi_get_device - get UBI device. * @ubi_num: UBI device number * @@ -877,6 +938,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) wake_up_process(ubi->bgt_thread); ubi_devices[ubi_num] = ubi; + ubi_enum_volumes(UBI_VOLUME_ADDED, ubi, NULL); return ubi_num; out_uif: @@ -921,14 +983,17 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) spin_lock(&ubi_devices_lock); ubi = ubi_devices[ubi_num]; - if (!ubi) { - spin_unlock(&ubi_devices_lock); + spin_unlock(&ubi_devices_lock); + + if (!ubi) return -EINVAL; - } + ubi_enum_volumes(UBI_VOLUME_DELETED, ubi, NULL); + spin_lock(&ubi_devices_lock); if (ubi->ref_count) { if (!anyway) { spin_unlock(&ubi_devices_lock); + ubi_enum_volumes(UBI_VOLUME_ADDED, ubi, NULL); return -EBUSY; } /* This may only happen if there is a bug */ diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index f8e0f68..b7541f6 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -394,6 +394,8 @@ static ssize_t vol_cdev_write(struct file *file, const char __user *buf, } vol->checked = 1; ubi_gluebi_updated(vol); + ubi_volume_notify(UBI_VOLUME_CHANGED, + ubi->ubi_num, vol->vol_id); revoke_exclusive(desc, UBI_READWRITE); } diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index 4abbe57..db247e7 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c @@ -656,3 +656,49 @@ int ubi_sync(int ubi_num) return 0; } EXPORT_SYMBOL_GPL(ubi_sync); + +BLOCKING_NOTIFIER_HEAD(ubi_notifiers); + +/** + * ubi_register_volume_notifier - register the volume notification function. + * @nb: pointer to the filled struct ¬ifier_block + * @ignore_existing: boolean flag; if set to 1, UBI will not send notifications + * about ADDing existing volumes + * + * The function @nb.notifier_call will be called when volume is added, + * removed, resized or renamed. Its first parameter is &enum + * ubi_volume_notification_type, and the second points to the structure + * that contains information about "changed" volume - ubi_num and + * volume_id. When the notifier is called, it is safe to use all UBI API. + * + * Returns %0 on success, error code otherwise. + */ +int ubi_register_volume_notifier(struct notifier_block *nb, + int ignore_existing) +{ + int err; + + err = blocking_notifier_chain_register(&ubi_notifiers, nb); + if (err != 0) + return err; + if (ignore_existing) + return err; + down_read(&ubi_notifiers.rwsem); + + ubi_enum_all_volumes(UBI_VOLUME_ADDED, nb); + up_read(&ubi_notifiers.rwsem); + return err; +} +EXPORT_SYMBOL_GPL(ubi_register_volume_notifier); + +/** + * ubi_unregister_volume_notifier - unregister the volume notifier. + * @nb: pointer to the filled struct ¬ifier_block + * + * Returns %0 on success, error code otherwise + */ +int ubi_unregister_volume_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&ubi_notifiers, nb); +} +EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier); diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index c055511..983bee1 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -38,6 +38,7 @@ #include #include #include +#include #include "ubi-media.h" #include "scan.h" @@ -457,6 +458,7 @@ extern const struct file_operations ubi_cdev_operations; extern const struct file_operations ubi_vol_cdev_operations; extern struct class *ubi_class; extern struct mutex ubi_devices_mutex; +extern struct blocking_notifier_head ubi_notifiers; /* vtbl.c */ int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, @@ -549,6 +551,9 @@ struct ubi_device *ubi_get_device(int ubi_num); void ubi_put_device(struct ubi_device *ubi); struct ubi_device *ubi_get_by_major(int major); int ubi_major2num(int major); +int ubi_enum_volumes(int ntype, struct ubi_device *ubi, + struct notifier_block *nb); +int ubi_enum_all_volumes(int ntype, struct notifier_block *nb); /* * ubi_rb_for_each_entry - walk an RB-tree. @@ -564,6 +569,25 @@ int ubi_major2num(int major); rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member)) /** + * ubi_volume_notify - notify all registered clients about volume changes. + * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc) + * @ubi_num: UBI device number + * @vol_id: ID of the created/removed/changed volume + * + * This is a helper function which notifies all subscribers about a volume + * change event. Returns zero in case of success and a negative error code in + * case of failure. + */ +static inline int ubi_volume_notify(int ntype, int ubi_num, int vol_id) +{ + struct ubi_volume_notification nt; + + nt.ubi_num = ubi_num; + nt.vol_id = vol_id; + return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt); +} + +/** * ubi_zalloc_vid_hdr - allocate a volume identifier header object. * @ubi: UBI device description object * @gfp_flags: GFP flags to allocate with diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index df54835..faf8d09 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -358,6 +358,7 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) ubi->vol_count += 1; spin_unlock(&ubi->volumes_lock); + ubi_volume_notify(UBI_VOLUME_ADDED, ubi->ubi_num, vol->vol_id); err = paranoid_check_volumes(ubi); return err; @@ -419,6 +420,8 @@ int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl) if (ubi->ro_mode) return -EROFS; + ubi_volume_notify(UBI_VOLUME_DELETED, ubi->ubi_num, vol_id); + spin_lock(&ubi->volumes_lock); if (vol->ref_count > 1) { /* @@ -475,6 +478,7 @@ out_err: ubi->volumes[vol_id] = vol; out_unlock: spin_unlock(&ubi->volumes_lock); + ubi_volume_notify(UBI_VOLUME_ADDED, ubi->ubi_num, vol_id); return err; } @@ -587,6 +591,7 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) (long long)vol->used_ebs * vol->usable_leb_size; } + ubi_volume_notify(UBI_VOLUME_CHANGED, ubi->ubi_num, vol->vol_id); err = paranoid_check_volumes(ubi); return err; @@ -632,6 +637,8 @@ int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list) vol->name_len = re->new_name_len; memcpy(vol->name, re->new_name, re->new_name_len + 1); spin_unlock(&ubi->volumes_lock); + ubi_volume_notify(UBI_VOLUME_RENAMED, + ubi->ubi_num, vol->vol_id); } } diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h index 6316faf..83e1eef 100644 --- a/include/linux/mtd/ubi.h +++ b/include/linux/mtd/ubi.h @@ -132,6 +132,38 @@ struct ubi_device_info { dev_t cdev; }; +/* + * struct ubi_volume_notification - information about changed volume. + * @ubi_num: UBI device number where the changed volume persists + * @vol_id: changed volume id + * + * Each notification about changed volume takes two parameters - first one + * is of type &enum ubi_volume_notification_type and indicates the type of + * volume change, and the second parameter is a pointer to the &struct + * ubi_volume_notification and describes the subject of change. + */ +struct ubi_volume_notification { + int ubi_num; + int vol_id; +}; + +/* + * enum - type of volume_change. + * @UBI_VOLUME_ADDED: volume has been added + * @UBI_VOLUME_DELETED: volume has been deleted + * @UBI_VOLUME_CHANGED: volume size has been changed + * @UBI_VOLUME_RENAMED: volume name has been changed + * + * Variable of this type is passed as the first parameter to the notification + * function. + */ +enum { + UBI_VOLUME_ADDED, + UBI_VOLUME_DELETED, + UBI_VOLUME_CHANGED, + UBI_VOLUME_RENAMED, +}; + /* UBI descriptor given to users when they open UBI volumes */ struct ubi_volume_desc; @@ -141,6 +173,10 @@ void ubi_get_volume_info(struct ubi_volume_desc *desc, struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, int mode); +int ubi_register_volume_notifier(struct notifier_block *nb, + int ignore_existing); +int ubi_unregister_volume_notifier(struct notifier_block *nb); + void ubi_close_volume(struct ubi_volume_desc *desc); int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, int len, int check);