Re: [PATCH v2 1/2] block: make __register_blkdev() return an error
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: 2021-09-28 00:20:46
Also in:
linux-fsdevel, linux-raid, linux-scsi, lkml
On 2021/09/28 7:03, Luis Chamberlain wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index 5dc9b3d32415..be0627345b21 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c@@ -1989,24 +1989,34 @@ static int ataflop_alloc_disk(unsigned int drive, unsigned int type) static DEFINE_MUTEX(ataflop_probe_lock); -static void ataflop_probe(dev_t dev) +static int ataflop_probe(dev_t dev) { int drive = MINOR(dev) & 3; int type = MINOR(dev) >> 2; + int err = 0; if (type) type--; - if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS) - return; + if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS) { + err = -EINVAL; + goto out; + } + mutex_lock(&ataflop_probe_lock); if (!unit[drive].disk[type]) { - if (ataflop_alloc_disk(drive, type) == 0) { - add_disk(unit[drive].disk[type]); + err = ataflop_alloc_disk(drive, type); + if (err == 0) { + err = add_disk(unit[drive].disk[type]); + if (err) + blk_cleanup_disk(unit[drive].disk[type]); unit[drive].registered[type] = true;
Why setting registered to true despite add_disk() failed? del_gendisk() without successful add_disk() sounds wrong. Don't we need to undo ataflop_alloc_disk() because it sets unit[drive].disk[type] to non-NULL ?
} } mutex_unlock(&ataflop_probe_lock); + +out: + return err; } static void atari_cleanup_floppy_disk(struct atari_floppy_struct *fs)
quoted hunk ↗ jump to hunk
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index c2bf4946f4e3..82a93044de95 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c@@ -426,10 +426,11 @@ static int brd_alloc(int i) return err; } -static void brd_probe(dev_t dev) +static int brd_probe(dev_t dev) { int i = MINOR(dev) / max_part; struct brd_device *brd; + int err = 0; mutex_lock(&brd_devices_mutex); list_for_each_entry(brd, &brd_devices, brd_list) {@@ -437,9 +438,11 @@ static void brd_probe(dev_t dev) goto out_unlock; } - brd_alloc(i); + err = brd_alloc(i); out_unlock: mutex_unlock(&brd_devices_mutex); + + return err; } static void brd_del_one(struct brd_device *brd)
https://lkml.kernel.org/r/e205f13d-18ff-a49c-0988-7de6ea5ff823@i-love.sakura.ne.jp will require this part to be updated.
quoted hunk ↗ jump to hunk
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 0434f28742e7..95a1c8ef62f7 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c@@ -4517,21 +4517,27 @@ static int floppy_alloc_disk(unsigned int drive, unsigned int type) static DEFINE_MUTEX(floppy_probe_lock); -static void floppy_probe(dev_t dev) +static int floppy_probe(dev_t dev) { unsigned int drive = (MINOR(dev) & 3) | ((MINOR(dev) & 0x80) >> 5); unsigned int type = (MINOR(dev) >> 2) & 0x1f; + int err = 0; if (drive >= N_DRIVE || !floppy_available(drive) || type >= ARRAY_SIZE(floppy_type)) - return; + return -EINVAL; mutex_lock(&floppy_probe_lock); if (!disks[drive][type]) { - if (floppy_alloc_disk(drive, type) == 0) - add_disk(disks[drive][type]); + if (floppy_alloc_disk(drive, type) == 0) { + err = add_disk(disks[drive][type]); + if (err) + blk_cleanup_disk(disks[drive][type]);
This makes future floppy_probe() no-op once add_disk() failed (or maybe a bad thing happens somewhere else), for disks[drive][type] was set to non-NULL by floppy_alloc_disk() but blk_cleanup_disk() does not reset it to NULL. According to floppy_module_exit() which tries to cleanup it, implementing undo might be complicated...
+ } } mutex_unlock(&floppy_probe_lock); + + return err; } static int __init do_floppy_init(void)