On Fri, Oct 16, 2020 at 03:20:41PM +0200, Christoph Hellwig wrote: > This interface is entirely unused, so remove them and various bits of > unreachable code.
Yeah, this is fair to remove -- there are no users. I'm not a fan of dropping it, but it can come back if anyone wants to provide a full generic block device implementation. Reviewed-by: Kees Cook <[email protected]> > > Signed-off-by: Christoph Hellwig <[email protected]> > --- > Documentation/admin-guide/pstore-blk.rst | 8 +-- > fs/pstore/blk.c | 79 ++---------------------- > include/linux/pstore_blk.h | 42 ------------- > 3 files changed, 7 insertions(+), 122 deletions(-) > > diff --git a/Documentation/admin-guide/pstore-blk.rst > b/Documentation/admin-guide/pstore-blk.rst > index d9ec8b0572d3b2..84477621384d85 100644 > --- a/Documentation/admin-guide/pstore-blk.rst > +++ b/Documentation/admin-guide/pstore-blk.rst > @@ -151,13 +151,7 @@ otherwise KMSG_DUMP_MAX. > Configurations for driver > ------------------------- > > -Only a block device driver cares about these configurations. A block device > -driver uses ``register_pstore_blk`` to register to pstore/blk. > - > -.. kernel-doc:: fs/pstore/blk.c > - :identifiers: register_pstore_blk > - > -A non-block device driver uses ``register_pstore_device`` with > +A device driver uses ``register_pstore_device`` with > ``struct pstore_device_info`` to register to pstore/blk. > > .. kernel-doc:: fs/pstore/blk.c > diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c > index fcd5563dde063c..7f8368e94b3604 100644 > --- a/fs/pstore/blk.c > +++ b/fs/pstore/blk.c > @@ -90,7 +90,6 @@ MODULE_PARM_DESC(blkdev, "block device for pstore storage"); > static DEFINE_MUTEX(pstore_blk_lock); > static struct block_device *psblk_bdev; > static struct pstore_zone_info *pstore_zone_info; > -static pstore_blk_panic_write_op blkdev_panic_write; > > struct bdev_info { > dev_t devt; > @@ -341,24 +340,7 @@ static ssize_t psblk_generic_blk_write(const char *buf, > size_t bytes, > return ret; > } > > -static ssize_t psblk_blk_panic_write(const char *buf, size_t size, > - loff_t off) > -{ > - int ret; > - > - if (!blkdev_panic_write) > - return -EOPNOTSUPP; > - > - /* size and off must align to SECTOR_SIZE for block device */ > - ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, > - size >> SECTOR_SHIFT); > - /* try next zone */ > - if (ret == -ENOMSG) > - return ret; > - return ret ? -EIO : size; > -} > - > -static int __register_pstore_blk(struct pstore_blk_info *info) > +static int __register_pstore_blk(void) > { > char bdev_name[BDEVNAME_SIZE]; > struct block_device *bdev; > @@ -378,68 +360,34 @@ static int __register_pstore_blk(struct pstore_blk_info > *info) > } > > /* only allow driver matching the @blkdev */ > - if (!binfo.devt || (!best_effort && > - MAJOR(binfo.devt) != info->major)) { > - pr_debug("invalid major %u (expect %u)\n", > - info->major, MAJOR(binfo.devt)); > + if (!binfo.devt) { > + pr_debug("no major\n"); > ret = -ENODEV; > goto err_put_bdev; > } > > /* psblk_bdev must be assigned before register to pstore/blk */ > psblk_bdev = bdev; > - blkdev_panic_write = info->panic_write; > - > - /* Copy back block device details. */ > - info->devt = binfo.devt; > - info->nr_sects = binfo.nr_sects; > - info->start_sect = binfo.start_sect; > > memset(&dev, 0, sizeof(dev)); > - dev.total_size = info->nr_sects << SECTOR_SHIFT; > - dev.flags = info->flags; > + dev.total_size = binfo.nr_sects << SECTOR_SHIFT; > dev.read = psblk_generic_blk_read; > dev.write = psblk_generic_blk_write; > - dev.erase = NULL; > - dev.panic_write = info->panic_write ? psblk_blk_panic_write : NULL; > > ret = __register_pstore_device(&dev); > if (ret) > goto err_put_bdev; > > bdevname(bdev, bdev_name); > - pr_info("attached %s%s\n", bdev_name, > - info->panic_write ? "" : " (no dedicated panic_write!)"); > + pr_info("attached %s (no dedicated panic_write!)\n", bdev_name); > return 0; > > err_put_bdev: > psblk_bdev = NULL; > - blkdev_panic_write = NULL; > psblk_put_bdev(bdev, holder); > return ret; > } > > -/** > - * register_pstore_blk() - register block device to pstore/blk > - * > - * @info: details on the desired block device interface > - * > - * Return: > - * * 0 - OK > - * * Others - something error. > - */ > -int register_pstore_blk(struct pstore_blk_info *info) > -{ > - int ret; > - > - mutex_lock(&pstore_blk_lock); > - ret = __register_pstore_blk(info); > - mutex_unlock(&pstore_blk_lock); > - > - return ret; > -} > -EXPORT_SYMBOL_GPL(register_pstore_blk); > - > static void __unregister_pstore_blk(unsigned int major) > { > struct pstore_device_info dev = { .read = psblk_generic_blk_read }; > @@ -449,24 +397,10 @@ static void __unregister_pstore_blk(unsigned int major) > if (psblk_bdev && MAJOR(psblk_bdev->bd_dev) == major) { > __unregister_pstore_device(&dev); > psblk_put_bdev(psblk_bdev, holder); > - blkdev_panic_write = NULL; > psblk_bdev = NULL; > } > } > > -/** > - * unregister_pstore_blk() - unregister block device from pstore/blk > - * > - * @major: the major device number of device > - */ > -void unregister_pstore_blk(unsigned int major) > -{ > - mutex_lock(&pstore_blk_lock); > - __unregister_pstore_blk(major); > - mutex_unlock(&pstore_blk_lock); > -} > -EXPORT_SYMBOL_GPL(unregister_pstore_blk); > - > /* get information of pstore/blk */ > int pstore_blk_get_config(struct pstore_blk_config *info) > { > @@ -483,12 +417,11 @@ EXPORT_SYMBOL_GPL(pstore_blk_get_config); > > static int __init pstore_blk_init(void) > { > - struct pstore_blk_info info = { }; > int ret = 0; > > mutex_lock(&pstore_blk_lock); > if (!pstore_zone_info && best_effort && blkdev[0]) > - ret = __register_pstore_blk(&info); > + ret = __register_pstore_blk(); > mutex_unlock(&pstore_blk_lock); > > return ret; > diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h > index 61e914522b0193..99564f93d77488 100644 > --- a/include/linux/pstore_blk.h > +++ b/include/linux/pstore_blk.h > @@ -7,48 +7,6 @@ > #include <linux/pstore.h> > #include <linux/pstore_zone.h> > > -/** > - * typedef pstore_blk_panic_write_op - panic write operation to block device > - * > - * @buf: the data to write > - * @start_sect: start sector to block device > - * @sects: sectors count on buf > - * > - * Return: On success, zero should be returned. Others excluding -ENOMSG > - * mean error. -ENOMSG means to try next zone. > - * > - * Panic write to block device must be aligned to SECTOR_SIZE. > - */ > -typedef int (*pstore_blk_panic_write_op)(const char *buf, sector_t > start_sect, > - sector_t sects); > - > -/** > - * struct pstore_blk_info - pstore/blk registration details > - * > - * @major: Which major device number to support with pstore/blk > - * @flags: The supported PSTORE_FLAGS_* from linux/pstore.h. > - * @panic_write:The write operation only used for the panic case. > - * This can be NULL, but is recommended to avoid losing > - * crash data if the kernel's IO path or work queues are > - * broken during a panic. > - * @devt: The dev_t that pstore/blk has attached to. > - * @nr_sects: Number of sectors on @devt. > - * @start_sect: Starting sector on @devt. > - */ > -struct pstore_blk_info { > - unsigned int major; > - unsigned int flags; > - pstore_blk_panic_write_op panic_write; > - > - /* Filled in by pstore/blk after registration. */ > - dev_t devt; > - sector_t nr_sects; > - sector_t start_sect; > -}; > - > -int register_pstore_blk(struct pstore_blk_info *info); > -void unregister_pstore_blk(unsigned int major); > - > /** > * struct pstore_device_info - back-end pstore/blk driver structure. > * > -- > 2.28.0 > -- Kees Cook
