From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755484AbbG0D6u (ORCPT ); Sun, 26 Jul 2015 23:58:50 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:51650 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755141AbbG0D6s (ORCPT ); Sun, 26 Jul 2015 23:58:48 -0400 X-AuditID: cbfee691-f79ca6d00000456a-a7-55b5ac64b9d6 From: Vishnu Pratap Singh To: axboe@kernel.dk, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Cc: cpgs@samsung.com, vishu13285@gmail.com, pintu.k@samsung.com, rohit.kr@samsung.com, Vishnu Pratap Singh Subject: [PATCH] block/genhd.c: Add error handling Date: Mon, 27 Jul 2015 09:27:18 +0530 Message-id: <1437969438-9181-1-git-send-email-vishnu.ps@samsung.com> X-Mailer: git-send-email 1.7.9.5 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrCLMWRmVeSWpSXmKPExsWyRsSkVjdlzdZQg55VihZz1q9hs1h9t5/N 4uUhTYvLu+awWfR9P8xu8by5lcViSt9dRostKx6yOnB47Jx1l93j8tlSjxMzfrN49G1Zxejx eZNcAGsUl01Kak5mWWqRvl0CV8aBVycZC97aVGw+e5qlgfGWYRcjB4eEgInEjzUqXYycQKaY xIV769m6GLk4hARWMErMfbuJHSJhIvH2wBFmEFtIYCmjxJ+1ThBFTUwSj27dAkuwCRhKbJh9 hB1kqIiAj8SLdfYgNcwCLYwSU0+vYwKpERYwkmjoWg82lEVAVWJJ+1KwOK+Ai8ThRWeYIA5S kJgzyQakV0Kgm13iR+8mZoh6AYlvkw+xQNTISmw6wAxxm6TEwRU3WCYwCi5gZFjFKJpakFxQ nJReZKpXnJhbXJqXrpecn7uJERi4p/89m7iD8f4B60OMAhyMSjy8F1S2hgqxJpYVV+YeYjQF 2jCRWUo0OR8YH3kl8YbGZkYWpiamxkbmlmZK4rw60j+DhQTSE0tSs1NTC1KL4otKc1KLDzEy cXBKNTAGiD0LDttxkNO6LvDp72+2DUdfMejPOP0yq6cs2v35t9iPh+wq5izTZ5XoXiUuGvIv 46D4hJmXf63XcQvvKWLj6b19oLXFZ4/0Dln+xw0SmZ1h9q07lbkNbp8+11dUwZcvHPc/snb2 9mc+v9ht/Ms2p7V67OPKLC74pfes4f+B4iXZ9su4bJRYijMSDbWYi4oTAQbzn9ZXAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprEIsWRmVeSWpSXmKPExsVy+t9jAd2UNVtDDbq2iFvMWb+GzWL13X42 i5eHNC0u75rDZtH3/TC7xfPmVhaLKX13GS22rHjI6sDhsXPWXXaPy2dLPU7M+M3i0bdlFaPH 501yAaxRDYw2GamJKalFCql5yfkpmXnptkrewfHO8aZmBoa6hpYW5koKeYm5qbZKLj4Bum6Z OUCnKCmUJeaUAoUCEouLlfTtME0IDXHTtYBpjND1DQmC6zEyQAMJaxgzDrw6yVjw1qZi89nT LA2Mtwy7GDk5JARMJN4eOMIMYYtJXLi3ng3EFhJYyijxZ61TFyMXkN3EJPHo1i2wIjYBQ4kN s4+wdzFycIgI+Ei8WGcPUsMs0MIoMfX0OiaQGmEBI4mGrvXsIDaLgKrEkvalYHFeAReJw4vO MIH0SggoSMyZZDOBkXsBI8MqRonUguSC4qT0XMO81HK94sTc4tK8dL3k/NxNjOD4eCa1g/Hg LvdDjAIcjEo8vBdUtoYKsSaWFVfmHmKU4GBWEuF9HAUU4k1JrKxKLcqPLyrNSS0+xGgKtH8i s5Rocj4wdvNK4g2NTcxNjU0tTSxMzCyVxHllN2wOFRJITyxJzU5NLUgtgulj4uCUamD0Vt+Q Hu3AK7PgvIrzvDWB3Z9+9S1ov+Tg8DfpFdPPp2Ky/s75KgqmU6uqzs96/W/NjfmR3apvw5hV fm/UtGAs2uN45oTFx7Ms5ts9ZzbuPsURF/BKJ/q7i8WKA0KPmhYtEZef8Y1rh2K7Nr/sI0lp h9jJ8stm/ktXjuq8eXSah6Jmm5fM+mQlluKMREMt5qLiRAD1Spx/pQIAAA== DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds error handling for blk_register_region(), register_disk(), add_disk(), disk_alloc_events() & disk_add_events(). add_disk() & register_disk() functions error handling is very much needed as this is used mainly by many modules like mmc, zram, mtd, scsi etc. But there is no error handling and it may cause stability issues also. Verfied on X86 based ubuntu machine. Signed-off-by: Vishnu Pratap Singh --- block/genhd.c | 92 ++++++++++++++++++++++++++++++++++--------------- include/linux/genhd.h | 4 +-- 2 files changed, 67 insertions(+), 29 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index e552e1b..8589e01 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -39,8 +39,8 @@ static struct device_type disk_type; static void disk_check_events(struct disk_events *ev, unsigned int *clearing_ptr); -static void disk_alloc_events(struct gendisk *disk); -static void disk_add_events(struct gendisk *disk); +static int disk_alloc_events(struct gendisk *disk); +static int disk_add_events(struct gendisk *disk); static void disk_del_events(struct gendisk *disk); static void disk_release_events(struct gendisk *disk); @@ -473,11 +473,11 @@ static char *bdevt_str(dev_t devt, char *buf) * range must be nonzero * The hash chain is sorted on range, so that subranges can override. */ -void blk_register_region(dev_t devt, unsigned long range, struct module *module, +int blk_register_region(dev_t devt, unsigned long range, struct module *module, struct kobject *(*probe)(dev_t, int *, void *), int (*lock)(dev_t, void *), void *data) { - kobj_map(bdev_map, devt, range, module, probe, lock, data); + return kobj_map(bdev_map, devt, range, module, probe, lock, data); } EXPORT_SYMBOL(blk_register_region); @@ -505,7 +505,7 @@ static int exact_lock(dev_t devt, void *data) return 0; } -static void register_disk(struct gendisk *disk) +static int register_disk(struct gendisk *disk) { struct device *ddev = disk_to_dev(disk); struct block_device *bdev; @@ -520,14 +520,15 @@ static void register_disk(struct gendisk *disk) /* delay uevents, until we scanned partition table */ dev_set_uevent_suppress(ddev, 1); - if (device_add(ddev)) - return; + err = device_add(ddev); + if (err) + return err; if (!sysfs_deprecated) { err = sysfs_create_link(block_depr, &ddev->kobj, kobject_name(&ddev->kobj)); if (err) { device_del(ddev); - return; + return err; } } @@ -558,6 +559,7 @@ static void register_disk(struct gendisk *disk) if (err < 0) goto exit; blkdev_put(bdev, FMODE_READ); + return 0; exit: /* announce disk after possible partitions are created */ @@ -569,6 +571,7 @@ exit: while ((part = disk_part_iter_next(&piter))) kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); disk_part_iter_exit(&piter); + return err; } /** @@ -577,10 +580,8 @@ exit: * * This function registers the partitioning information in @disk * with the kernel. - * - * FIXME: error handling */ -void add_disk(struct gendisk *disk) +int add_disk(struct gendisk *disk) { struct backing_dev_info *bdi; dev_t devt; @@ -598,7 +599,7 @@ void add_disk(struct gendisk *disk) retval = blk_alloc_devt(&disk->part0, &devt); if (retval) { WARN_ON(1); - return; + return retval; } disk_to_dev(disk)->devt = devt; @@ -608,16 +609,27 @@ void add_disk(struct gendisk *disk) disk->major = MAJOR(devt); disk->first_minor = MINOR(devt); - disk_alloc_events(disk); - + retval = disk_alloc_events(disk); + if (retval) + goto err_blk_devt; /* Register BDI before referencing it from bdev */ bdi = &disk->queue->backing_dev_info; - bdi_register_dev(bdi, disk_devt(disk)); + retval = bdi_register_dev(bdi, disk_devt(disk)); + if (retval) + goto err_alloc_event; - blk_register_region(disk_devt(disk), disk->minors, NULL, + retval = blk_register_region(disk_devt(disk), disk->minors, NULL, exact_match, exact_lock, disk); - register_disk(disk); - blk_register_queue(disk); + if (retval) + goto err_alloc_event; + + retval = register_disk(disk); + if (retval) + goto err_reg_region; + + retval = blk_register_queue(disk); + if (retval) + goto err_reg_disk; /* * Take an extra ref on queue which will be put on disk_release() @@ -627,9 +639,29 @@ void add_disk(struct gendisk *disk) retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, "bdi"); - WARN_ON(retval); + if (retval) + goto err_blk_reg_queue; + + retval = disk_add_events(disk); + if (retval) + goto err_sysfs; + + return 0; + +err_blk_devt: + blk_free_devt(devt); +err_alloc_event: + disk_del_events(disk); +err_reg_region: + blk_unregister_region(disk_devt(disk), disk->minors); +err_reg_disk: + del_gendisk(disk); +err_blk_reg_queue: + blk_unregister_queue(disk); +err_sysfs: + sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); + return retval; - disk_add_events(disk); } EXPORT_SYMBOL(add_disk); @@ -1779,17 +1811,17 @@ module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, /* * disk_{alloc|add|del|release}_events - initialize and destroy disk_events. */ -static void disk_alloc_events(struct gendisk *disk) +static int disk_alloc_events(struct gendisk *disk) { struct disk_events *ev; if (!disk->fops->check_events) - return; + return 0; ev = kzalloc(sizeof(*ev), GFP_KERNEL); if (!ev) { pr_warn("%s: failed to initialize events\n", disk->disk_name); - return; + return -ENOMEM; } INIT_LIST_HEAD(&ev->node); @@ -1801,17 +1833,22 @@ static void disk_alloc_events(struct gendisk *disk) INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); disk->ev = ev; + return 0; } -static void disk_add_events(struct gendisk *disk) +static int disk_add_events(struct gendisk *disk) { + int ret; + if (!disk->ev) - return; + return 0; - /* FIXME: error handling */ - if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0) + ret = sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs); + if (ret) { pr_warn("%s: failed to create sysfs files for events\n", disk->disk_name); + return ret; + } mutex_lock(&disk_events_mutex); list_add_tail(&disk->ev->node, &disk_events); @@ -1822,6 +1859,7 @@ static void disk_add_events(struct gendisk *disk) * unblock kicks it into action. */ __disk_unblock_events(disk, true); + return ret; } static void disk_del_events(struct gendisk *disk) diff --git a/include/linux/genhd.h b/include/linux/genhd.h index ec274e0..9bcd710 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -416,7 +416,7 @@ static inline void free_part_info(struct hd_struct *part) extern void part_round_stats(int cpu, struct hd_struct *part); /* block/genhd.c */ -extern void add_disk(struct gendisk *disk); +extern int add_disk(struct gendisk *disk); extern void del_gendisk(struct gendisk *gp); extern struct gendisk *get_gendisk(dev_t dev, int *partno); extern struct block_device *bdget_disk(struct gendisk *disk, int partno); @@ -619,7 +619,7 @@ extern struct gendisk *alloc_disk_node(int minors, int node_id); extern struct gendisk *alloc_disk(int minors); extern struct kobject *get_disk(struct gendisk *disk); extern void put_disk(struct gendisk *disk); -extern void blk_register_region(dev_t devt, unsigned long range, +extern int blk_register_region(dev_t devt, unsigned long range, struct module *module, struct kobject *(*probe)(dev_t, int *, void *), int (*lock)(dev_t, void *), -- 1.7.9.5