diff options
Diffstat (limited to 'drivers/mtd/ubi/vmt.c')
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 88 |
1 files changed, 58 insertions, 30 deletions
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 3d6ac029c177..18ef1e1da496 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -63,21 +63,24 @@ static struct device_attribute attr_vol_upd_marker = * B. process 2 removes volume Y; * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file; * - * What we want to do in a situation like that is to return error when the file - * is read. This is done by means of the 'removed' flag and the 'vol_lock' of - * the UBI volume description object. + * In this situation, this function will return %-ENODEV because it will find + * out that the volume was removed from the @ubi->volumes array. */ static ssize_t vol_attribute_show(struct device *dev, struct device_attribute *attr, char *buf) { - int ret = -ENODEV; + int ret; struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); + struct ubi_device *ubi = vol->ubi; - spin_lock(&vol->ubi->volumes_lock); - if (vol->removed) { - spin_unlock(&vol->ubi->volumes_lock); - return ret; + spin_lock(&ubi->volumes_lock); + if (!ubi->volumes[vol->vol_id]) { + spin_unlock(&ubi->volumes_lock); + return -ENODEV; } + /* Take a reference to prevent volume removal */ + vol->ref_count += 1; + spin_unlock(&ubi->volumes_lock); if (attr == &attr_vol_reserved_ebs) ret = sprintf(buf, "%d\n", vol->reserved_pebs); @@ -102,8 +105,13 @@ static ssize_t vol_attribute_show(struct device *dev, else if (attr == &attr_vol_upd_marker) ret = sprintf(buf, "%d\n", vol->upd_marker); else - BUG(); - spin_unlock(&vol->ubi->volumes_lock); + /* This must be a bug */ + ret = -EINVAL; + + spin_lock(&ubi->volumes_lock); + vol->ref_count -= 1; + ubi_assert(vol->ref_count >= 0); + spin_unlock(&ubi->volumes_lock); return ret; } @@ -179,7 +187,7 @@ static void volume_sysfs_close(struct ubi_volume *vol) * @req: volume creation request * * This function creates volume described by @req. If @req->vol_id id - * %UBI_VOL_NUM_AUTO, this function automatically assigne ID to the new volume + * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume * and saves it in @req->vol_id. Returns zero in case of success and a negative * error code in case of failure. */ @@ -261,7 +269,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) memcpy(vol->name, req->name, vol->name_len + 1); vol->exclusive = 1; vol->ubi = ubi; - ubi->volumes[vol_id] = vol; spin_unlock(&ubi->volumes_lock); /* @@ -345,6 +352,7 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) spin_lock(&ubi->volumes_lock); ubi->vol_count += 1; vol->exclusive = 0; + ubi->volumes[vol_id] = vol; spin_unlock(&ubi->volumes_lock); paranoid_check_volumes(ubi); @@ -353,7 +361,7 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) out_sysfs: /* - * We have degistered our device, we should not free the volume* + * We have registered our device, we should not free the volume* * description object in this function in case of an error - it is * freed by the release function. * @@ -373,7 +381,6 @@ out_acc: spin_lock(&ubi->volumes_lock); ubi->rsvd_pebs -= vol->reserved_pebs; ubi->avail_pebs += vol->reserved_pebs; - ubi->volumes[vol_id] = NULL; out_unlock: spin_unlock(&ubi->volumes_lock); mutex_unlock(&ubi->volumes_mutex); @@ -407,25 +414,32 @@ int ubi_remove_volume(struct ubi_volume_desc *desc) return -EROFS; mutex_lock(&ubi->volumes_mutex); + spin_lock(&ubi->volumes_lock); + if (vol->ref_count > 1) { + /* + * The volume is busy, probably someone is reading one of its + * sysfs files. + */ + err = -EBUSY; + goto out_unlock; + } + ubi->volumes[vol_id] = NULL; + spin_unlock(&ubi->volumes_lock); + err = ubi_destroy_gluebi(vol); if (err) - goto out; + goto out_err; err = ubi_change_vtbl_record(ubi, vol_id, NULL); if (err) - goto out; + goto out_err; for (i = 0; i < vol->reserved_pebs; i++) { err = ubi_eba_unmap_leb(ubi, vol, i); if (err) - goto out; + goto out_err; } - spin_lock(&ubi->volumes_lock); - vol->removed = 1; - ubi->volumes[vol_id] = NULL; - spin_unlock(&ubi->volumes_lock); - kfree(vol->eba_tbl); vol->eba_tbl = NULL; cdev_del(&vol->cdev); @@ -447,7 +461,15 @@ int ubi_remove_volume(struct ubi_volume_desc *desc) spin_unlock(&ubi->volumes_lock); paranoid_check_volumes(ubi); -out: + mutex_unlock(&ubi->volumes_mutex); + return 0; + +out_err: + ubi_err("cannot remove volume %d, error %d", vol_id, err); + spin_lock(&ubi->volumes_lock); + ubi->volumes[vol_id] = vol; +out_unlock: + spin_unlock(&ubi->volumes_lock); mutex_unlock(&ubi->volumes_mutex); return err; } @@ -494,8 +516,17 @@ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs) for (i = 0; i < reserved_pebs; i++) new_mapping[i] = UBI_LEB_UNMAPPED; - /* Reserve physical eraseblocks */ mutex_lock(&ubi->volumes_mutex); + spin_lock(&ubi->volumes_lock); + if (vol->ref_count > 1) { + spin_unlock(&ubi->volumes_lock); + err = -EBUSY; + goto out_free; + } + spin_unlock(&ubi->volumes_lock); + + + /* Reserve physical eraseblocks */ pebs = reserved_pebs - vol->reserved_pebs; if (pebs > 0) { spin_lock(&ubi->volumes_lock); @@ -577,8 +608,8 @@ out_free: * @ubi: UBI device description object * @vol: volume description object * - * This function adds an existin volume and initializes all its data - * structures. Returnes zero in case of success and a negative error code in + * This function adds an existing volume and initializes all its data + * structures. Returns zero in case of success and a negative error code in * case of failure. */ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) @@ -588,7 +619,6 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) dbg_msg("add volume %d", vol_id); ubi_dbg_dump_vol_info(vol); - ubi_assert(vol); /* Register character device for the volume */ cdev_init(&vol->cdev, &ubi_vol_cdev_operations); @@ -645,11 +675,9 @@ void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol) int err; dbg_msg("free volume %d", vol->vol_id); - ubi_assert(vol); - vol->removed = 1; - err = ubi_destroy_gluebi(vol); ubi->volumes[vol->vol_id] = NULL; + err = ubi_destroy_gluebi(vol); cdev_del(&vol->cdev); volume_sysfs_close(vol); } |
