diff options
| -rw-r--r-- | drivers/mtd/ubi/build.c | 142 | ||||
| -rw-r--r-- | drivers/mtd/ubi/cdev.c | 34 | ||||
| -rw-r--r-- | drivers/mtd/ubi/eba.c | 5 | ||||
| -rw-r--r-- | drivers/mtd/ubi/kapi.c | 59 | ||||
| -rw-r--r-- | drivers/mtd/ubi/ubi.h | 9 | ||||
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 14 | ||||
| -rw-r--r-- | drivers/mtd/ubi/wl.c | 1 |
7 files changed, 201 insertions, 63 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 3f37b16f8774..a4faf71ee3f2 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -64,9 +64,6 @@ static int mtd_devs = 0; /* MTD devices specification parameters */ static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES]; -/* All UBI devices in system */ -struct ubi_device *ubi_devices[UBI_MAX_DEVICES]; - /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */ struct class *ubi_class; @@ -83,6 +80,12 @@ static struct miscdevice ubi_ctrl_cdev = { .fops = &ubi_ctrl_cdev_operations, }; +/* All UBI devices in system */ +static struct ubi_device *ubi_devices[UBI_MAX_DEVICES]; + +/* Protects @ubi_devices and @ubi->ref_count */ +static DEFINE_SPINLOCK(ubi_devices_lock); + /* "Show" method for files in '/<sysfs>/class/ubi/' */ static ssize_t ubi_version_show(struct class *class, char *buf) { @@ -118,37 +121,145 @@ static struct device_attribute dev_min_io_size = static struct device_attribute dev_bgt_enabled = __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL); +/** + * ubi_get_device - get UBI device. + * @ubi_num: UBI device number + * + * This function returns UBI device description object for UBI device number + * @ubi_num, or %NULL if the device does not exist. This function increases the + * device reference count to prevent removal of the device. In other words, the + * device cannot be removed if its reference count is not zero. + */ +struct ubi_device *ubi_get_device(int ubi_num) +{ + struct ubi_device *ubi; + + spin_lock(&ubi_devices_lock); + ubi = ubi_devices[ubi_num]; + if (ubi) { + ubi_assert(ubi->ref_count >= 0); + ubi->ref_count += 1; + get_device(&ubi->dev); + } + spin_unlock(&ubi_devices_lock); + + return ubi; +} + +/** + * ubi_put_device - drop an UBI device reference. + * @ubi: UBI device description object + */ +void ubi_put_device(struct ubi_device *ubi) +{ + spin_lock(&ubi_devices_lock); + ubi->ref_count -= 1; + put_device(&ubi->dev); + spin_unlock(&ubi_devices_lock); +} + +/** + * ubi_get_by_major - get UBI device description object by character device + * major number. + * @major: major number + * + * This function is similar to 'ubi_get_device()', but it searches the device + * by its major number. + */ +struct ubi_device *ubi_get_by_major(int major) +{ + int i; + struct ubi_device *ubi; + + spin_lock(&ubi_devices_lock); + for (i = 0; i < UBI_MAX_DEVICES; i++) { + ubi = ubi_devices[i]; + if (ubi && MAJOR(ubi->cdev.dev) == major) { + ubi_assert(ubi->ref_count >= 0); + ubi->ref_count += 1; + get_device(&ubi->dev); + spin_unlock(&ubi_devices_lock); + return ubi; + } + } + spin_unlock(&ubi_devices_lock); + + return NULL; +} + +/** + * ubi_major2num - get UBI device number by character device major number. + * @major: major number + * + * This function searches UBI device number object by its major number. If UBI + * device was not found, this function returns -ENODEV, othewise the UBI device + * number is returned. + */ +int ubi_major2num(int major) +{ + int i, ubi_num = -ENODEV; + + spin_lock(&ubi_devices_lock); + for (i = 0; i < UBI_MAX_DEVICES; i++) { + struct ubi_device *ubi = ubi_devices[i]; + + if (ubi && MAJOR(ubi->cdev.dev) == major) { + ubi_num = ubi->ubi_num; + break; + } + } + spin_unlock(&ubi_devices_lock); + + return ubi_num; +} + /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */ static ssize_t dev_attribute_show(struct device *dev, struct device_attribute *attr, char *buf) { - const struct ubi_device *ubi; + ssize_t ret; + struct ubi_device *ubi; + /* + * The below code looks weird, but it actually makes sense. We get the + * UBI device reference from the contained 'struct ubi_device'. But it + * is unclear if the device was removed or not yet. Indeed, if the + * device was removed before we increased its reference count, + * 'ubi_get_device()' will return -ENODEV and we fail. + * + * Remember, 'struct ubi_device' is freed in the release function, so + * we still can use 'ubi->ubi_num'. + */ ubi = container_of(dev, struct ubi_device, dev); + ubi = ubi_get_device(ubi->ubi_num); + if (!ubi) + return -ENODEV; + if (attr == &dev_eraseblock_size) - return sprintf(buf, "%d\n", ubi->leb_size); + ret = sprintf(buf, "%d\n", ubi->leb_size); else if (attr == &dev_avail_eraseblocks) - return sprintf(buf, "%d\n", ubi->avail_pebs); + ret = sprintf(buf, "%d\n", ubi->avail_pebs); else if (attr == &dev_total_eraseblocks) - return sprintf(buf, "%d\n", ubi->good_peb_count); + ret = sprintf(buf, "%d\n", ubi->good_peb_count); else if (attr == &dev_volumes_count) - return sprintf(buf, "%d\n", ubi->vol_count); + ret = sprintf(buf, "%d\n", ubi->vol_count); else if (attr == &dev_max_ec) - return sprintf(buf, "%d\n", ubi->max_ec); + ret = sprintf(buf, "%d\n", ubi->max_ec); else if (attr == &dev_reserved_for_bad) - return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs); + ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs); else if (attr == &dev_bad_peb_count) - return sprintf(buf, "%d\n", ubi->bad_peb_count); + ret = sprintf(buf, "%d\n", ubi->bad_peb_count); else if (attr == &dev_max_vol_count) - return sprintf(buf, "%d\n", ubi->vtbl_slots); + ret = sprintf(buf, "%d\n", ubi->vtbl_slots); else if (attr == &dev_min_io_size) - return sprintf(buf, "%d\n", ubi->min_io_size); + ret = sprintf(buf, "%d\n", ubi->min_io_size); else if (attr == &dev_bgt_enabled) - return sprintf(buf, "%d\n", ubi->thread_enabled); + ret = sprintf(buf, "%d\n", ubi->thread_enabled); else BUG(); - return 0; + ubi_put_device(ubi); + return ret; } /* Fake "release" method for UBI devices */ @@ -670,6 +781,7 @@ static void detach_mtd_dev(struct ubi_device *ubi) int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index; dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num); + ubi_assert(ubi->ref_count == 0); uif_close(ubi); ubi_eba_close(ubi); ubi_wl_close(ubi); diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index bc900d24cdba..01978b57e9cb 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -56,23 +56,6 @@ #endif /** - * major_to_device - get UBI device object by character device major number. - * @major: major number - * - * This function returns a pointer to the UBI device object. - */ -static struct ubi_device *major_to_device(int major) -{ - int i; - - for (i = 0; i < UBI_MAX_DEVICES; i++) - if (ubi_devices[i] && MAJOR(ubi_devices[i]->cdev.dev) == major) - return ubi_devices[i]; - BUG(); - return NULL; -} - -/** * get_exclusive - get exclusive access to an UBI volume. * @desc: volume descriptor * @@ -129,9 +112,11 @@ static void revoke_exclusive(struct ubi_volume_desc *desc, int mode) static int vol_cdev_open(struct inode *inode, struct file *file) { struct ubi_volume_desc *desc; - const struct ubi_device *ubi = major_to_device(imajor(inode)); - int vol_id = iminor(inode) - 1; - int mode; + int vol_id = iminor(inode) - 1, mode, ubi_num; + + ubi_num = ubi_major2num(imajor(inode)); + if (ubi_num < 0) + return ubi_num; if (file->f_mode & FMODE_WRITE) mode = UBI_READWRITE; @@ -140,7 +125,7 @@ static int vol_cdev_open(struct inode *inode, struct file *file) dbg_msg("open volume %d, mode %d", vol_id, mode); - desc = ubi_open_volume(ubi->ubi_num, vol_id, mode); + desc = ubi_open_volume(ubi_num, vol_id, mode); if (IS_ERR(desc)) return PTR_ERR(desc); @@ -586,9 +571,9 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file, if (!capable(CAP_SYS_RESOURCE)) return -EPERM; - ubi = major_to_device(imajor(inode)); - if (IS_ERR(ubi)) - return PTR_ERR(ubi); + ubi = ubi_get_by_major(imajor(inode)); + if (!ubi) + return -ENODEV; switch (cmd) { /* Create volume command */ @@ -695,6 +680,7 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file, break; } + ubi_put_device(ubi); return err; } diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index c94f475758de..85297cde4ac5 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -339,6 +339,7 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol, { int err, pnum, vol_id = vol->vol_id; + ubi_assert(ubi->ref_count > 0); ubi_assert(vol->ref_count > 0); if (ubi->ro_mode) @@ -389,6 +390,7 @@ int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, struct ubi_vid_hdr *vid_hdr; uint32_t uninitialized_var(crc); + ubi_assert(ubi->ref_count > 0); ubi_assert(vol->ref_count > 0); err = leb_read_lock(ubi, vol_id, lnum); @@ -614,6 +616,7 @@ int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, int err, pnum, tries = 0, vol_id = vol->vol_id; struct ubi_vid_hdr *vid_hdr; + ubi_assert(ubi->ref_count > 0); ubi_assert(vol->ref_count > 0); if (ubi->ro_mode) @@ -749,6 +752,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol, struct ubi_vid_hdr *vid_hdr; uint32_t crc; + ubi_assert(ubi->ref_count > 0); ubi_assert(vol->ref_count > 0); if (ubi->ro_mode) @@ -865,6 +869,7 @@ int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, struct ubi_vid_hdr *vid_hdr; uint32_t crc; + ubi_assert(ubi->ref_count > 0); ubi_assert(vol->ref_count > 0); if (ubi->ro_mode) diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index 780c273ff452..4ec3a33b2577 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c @@ -30,23 +30,27 @@ * @ubi_num: UBI device number * @di: the information is stored here * - * This function returns %0 in case of success and a %-ENODEV if there is no - * such UBI device. + * This function returns %0 in case of success, %-EINVAL if the UBI device + * number is invalid, and %-ENODEV if there is no such UBI device. */ int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) { - const struct ubi_device *ubi; + struct ubi_device *ubi; - if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || - !ubi_devices[ubi_num]) + if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) + return -EINVAL; + + ubi = ubi_get_device(ubi_num); + if (!ubi) return -ENODEV; - ubi = ubi_devices[ubi_num]; di->ubi_num = ubi->ubi_num; di->leb_size = ubi->leb_size; di->min_io_size = ubi->min_io_size; di->ro_mode = ubi->ro_mode; di->cdev = ubi->cdev.dev; + + ubi_put_device(ubi); return 0; } EXPORT_SYMBOL_GPL(ubi_get_device_info); @@ -111,16 +115,23 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) mode != UBI_EXCLUSIVE) return ERR_PTR(-EINVAL); - ubi = ubi_devices[ubi_num]; + /* + * First of all, we have to get the UBI device to prevent its removal. + */ + ubi = ubi_get_device(ubi_num); if (!ubi) return ERR_PTR(-ENODEV); - if (vol_id < 0 || vol_id >= ubi->vtbl_slots) - return ERR_PTR(-EINVAL); + if (vol_id < 0 || vol_id >= ubi->vtbl_slots) { + err = -EINVAL; + goto out_put_ubi; + } desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); - if (!desc) - return ERR_PTR(-ENOMEM); + if (!desc) { + err = -ENOMEM; + goto out_put_ubi; + } err = -ENODEV; if (!try_module_get(THIS_MODULE)) @@ -188,6 +199,8 @@ out_unlock: module_put(THIS_MODULE); out_free: kfree(desc); +out_put_ubi: + ubi_put_device(ubi); return ERR_PTR(err); } EXPORT_SYMBOL_GPL(ubi_open_volume); @@ -205,6 +218,7 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, { int i, vol_id = -1, len; struct ubi_device *ubi; + struct ubi_volume_desc *ret; dbg_msg("open volume %s, mode %d", name, mode); @@ -218,7 +232,7 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) return ERR_PTR(-EINVAL); - ubi = ubi_devices[ubi_num]; + ubi = ubi_get_device(ubi_num); if (!ubi) return ERR_PTR(-ENODEV); @@ -234,10 +248,17 @@ struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, } spin_unlock(&ubi->volumes_lock); - if (vol_id < 0) - return ERR_PTR(-ENODEV); + if (vol_id >= 0) + ret = ubi_open_volume(ubi_num, vol_id, mode); + else + ret = ERR_PTR(-ENODEV); - return ubi_open_volume(ubi_num, vol_id, mode); + /* + * We should put the UBI device even in case of success, because + * 'ubi_open_volume()' took a reference as well. + */ + ubi_put_device(ubi); + return ret; } EXPORT_SYMBOL_GPL(ubi_open_volume_nm); @@ -248,10 +269,11 @@ EXPORT_SYMBOL_GPL(ubi_open_volume_nm); void ubi_close_volume(struct ubi_volume_desc *desc) { struct ubi_volume *vol = desc->vol; + struct ubi_device *ubi = vol->ubi; dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode); - spin_lock(&vol->ubi->volumes_lock); + spin_lock(&ubi->volumes_lock); switch (desc->mode) { case UBI_READONLY: vol->readers -= 1; @@ -263,10 +285,11 @@ void ubi_close_volume(struct ubi_volume_desc *desc) vol->exclusive = 0; } vol->ref_count -= 1; - spin_unlock(&vol->ubi->volumes_lock); + spin_unlock(&ubi->volumes_lock); - put_device(&vol->dev); kfree(desc); + put_device(&vol->dev); + ubi_put_device(ubi); module_put(THIS_MODULE); } EXPORT_SYMBOL_GPL(ubi_close_volume); diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 21c028366fd2..91fde0e8ff58 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -245,6 +245,7 @@ struct ubi_wl_entry; * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, * @vol->readers, @vol->writers, @vol->exclusive, * @vol->ref_count, @vol->mapping and @vol->eba_tbl. + * @ref_count: count of references on the UBI device * * @rsvd_pebs: count of reserved physical eraseblocks * @avail_pebs: count of available physical eraseblocks @@ -325,6 +326,7 @@ struct ubi_device { int vol_count; struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT]; spinlock_t volumes_lock; + int ref_count; int rsvd_pebs; int avail_pebs; @@ -401,7 +403,6 @@ extern struct kmem_cache *ubi_wl_entry_slab; extern struct file_operations ubi_ctrl_cdev_operations; extern struct file_operations ubi_cdev_operations; extern struct file_operations ubi_vol_cdev_operations; -extern struct ubi_device *ubi_devices[]; extern struct class *ubi_class; /* vtbl.c */ @@ -479,6 +480,12 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_hdr *vid_hdr); +/* build.c */ +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); + /* * ubi_rb_for_each_entry - walk an RB-tree. * @rb: a pointer to type 'struct rb_node' to to use as a loop counter diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 3ed63dc37386..42d3dd70f2d0 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -71,11 +71,16 @@ static ssize_t vol_attribute_show(struct device *dev, { int ret; struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev); - struct ubi_device *ubi = vol->ubi; + struct ubi_device *ubi; + + ubi = ubi_get_device(vol->ubi->ubi_num); + if (!ubi) + return -ENODEV; spin_lock(&ubi->volumes_lock); if (!ubi->volumes[vol->vol_id]) { spin_unlock(&ubi->volumes_lock); + ubi_put_device(ubi); return -ENODEV; } /* Take a reference to prevent volume removal */ @@ -108,10 +113,12 @@ static ssize_t vol_attribute_show(struct device *dev, /* This must be a bug */ ret = -EINVAL; + /* We've done the operation, drop volume and UBI device references */ spin_lock(&ubi->volumes_lock); vol->ref_count -= 1; ubi_assert(vol->ref_count >= 0); spin_unlock(&ubi->volumes_lock); + ubi_put_device(ubi); return ret; } @@ -260,6 +267,7 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) } ubi->avail_pebs -= vol->reserved_pebs; ubi->rsvd_pebs += vol->reserved_pebs; + spin_unlock(&ubi->volumes_lock); vol->vol_id = vol_id; vol->alignment = req->alignment; @@ -267,9 +275,7 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) vol->vol_type = req->vol_type; vol->name_len = req->name_len; memcpy(vol->name, req->name, vol->name_len + 1); - vol->exclusive = 1; vol->ubi = ubi; - spin_unlock(&ubi->volumes_lock); /* * Finish all pending erases because there may be some LEBs belonging @@ -350,8 +356,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) goto out_sysfs; spin_lock(&ubi->volumes_lock); - ubi->vol_count += 1; - vol->exclusive = 0; ubi->volumes[vol_id] = vol; spin_unlock(&ubi->volumes_lock); diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 7d32f71d6f1e..bfc64c824165 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -1303,6 +1303,7 @@ int ubi_wl_flush(struct ubi_device *ubi) * Make sure all the works which have been done in parallel are * finished. */ + ubi_assert(ubi->ref_count > 0); down_write(&ubi->work_sem); up_write(&ubi->work_sem); |