| Message ID | 1445533241-10292-1-git-send-email-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 2015-10-22 at 10:00 -0700, John Stultz wrote: > From: Colin Cross <ccross@android.com> > > It is quite common for Android devices to utilize more > then 8 partitions on internal eMMC storage. > > The vanilla kernel can support this via > CONFIG_MMC_BLOCK_MINORS, however that solution caps the > system to 256 minors total, which limits the number of > mmc cards the system can support. [...] This commit was intended to allow support for 256 cards with any number of partitions: commit a26eba614afff0e39594101bcb73014a9a22fb33 Author: Ben Hutchings <ben@decadent.org.uk> Date: Thu Nov 6 03:35:09 2014 +0000 mmc: block: Increase max_devices I don't think the new patch is sufficient or necessary to increase the limit further. Do you have a compatibility requirement to retain the numbering of the first 7 partitions? Ben.
On Thu, 2015-10-22 at 19:07 +0100, Ben Hutchings wrote: > On Thu, 2015-10-22 at 10:00 -0700, John Stultz wrote: > > From: Colin Cross <ccross@android.com> > > > > It is quite common for Android devices to utilize more > > then 8 partitions on internal eMMC storage. > > > > The vanilla kernel can support this via > > CONFIG_MMC_BLOCK_MINORS, however that solution caps the > > system to 256 minors total, which limits the number of > > mmc cards the system can support. > [...] > > This commit was intended to allow support for 256 cards with any number > of partitions: > > commit a26eba614afff0e39594101bcb73014a9a22fb33 > Author: Ben Hutchings <ben@decadent.org.uk> > Date: Thu Nov 6 03:35:09 2014 +0000 > > mmc: block: Increase max_devices > > I don't think the new patch is sufficient or necessary to increase the > limit further. Of course, this does allow use of more than any predefined number of partitions per card, the same as sd can. So it still has some usefulness, though the commit message seems to overstate that. Ben. > Do you have a compatibility requirement to retain the numbering of the > first 7 partitions? > > Ben. >
On 22 October 2015 at 19:00, John Stultz <john.stultz@linaro.org> wrote: > From: Colin Cross <ccross@android.com> > > It is quite common for Android devices to utilize more > then 8 partitions on internal eMMC storage. > > The vanilla kernel can support this via > CONFIG_MMC_BLOCK_MINORS, however that solution caps the > system to 256 minors total, which limits the number of > mmc cards the system can support. > > This patch, which has been carried for quite awhile in > the AOSP common tree, provides an alternative solution > that doesn't seem to limit the total card count. So I > wanted to submit it for consideration upstream. > > This patch sets the GENHD_FL_EXT_DEVT flag, which will > allocate minor number in major 259 for partitions past > disk->minors. > > It also removes the use of disk_devt to determine devidx > from md->disk. md->disk->first_minor is always initialized > from devidx and can always be used to recover it. > > Thoughts or feedback would be greatly appreciated. > > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Ben Hutchings <ben@decadent.org.uk> > Cc: Chuanxiao Dong <chuanxiao.dong@intel.com> > Cc: Shawn Lin <shawn.lin@rock-chips.com> > Cc: Austin S Hemmelgarn <ahferroin7@gmail.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Android Kernel Team <kernel-team@android.com> > Cc: linux-mmc@vger.kernel.org > Signed-off-by: Colin Cross <ccross@android.com> > [jstultz: Added context to commit message] > Signed-off-by: John Stultz <john.stultz@linaro.org> Thanks, applied for next! I did some minor changes to the change-log, and updated the prefix of the commit msg header. Kind regards Uffe > --- > v2: Added context to commit message about CONFIG_MMC_BLOCK_MINORS > and its limitations. > > drivers/mmc/card/block.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index c742cfd..564436e 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -172,11 +172,7 @@ static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk) > > static inline int mmc_get_devidx(struct gendisk *disk) > { > - int devmaj = MAJOR(disk_devt(disk)); > - int devidx = MINOR(disk_devt(disk)) / perdev_minors; > - > - if (!devmaj) > - devidx = disk->first_minor / perdev_minors; > + int devidx = disk->first_minor / perdev_minors; > return devidx; > } > > @@ -2162,6 +2158,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, > md->disk->queue = md->queue.queue; > md->disk->driverfs_dev = parent; > set_disk_ro(md->disk, md->read_only || default_ro); > + md->disk->flags = GENHD_FL_EXT_DEVT; > if (area_type & (MMC_BLK_DATA_AREA_RPMB | MMC_BLK_DATA_AREA_BOOT)) > md->disk->flags |= GENHD_FL_NO_PART_SCAN; > > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index c742cfd..564436e 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -172,11 +172,7 @@ static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk) static inline int mmc_get_devidx(struct gendisk *disk) { - int devmaj = MAJOR(disk_devt(disk)); - int devidx = MINOR(disk_devt(disk)) / perdev_minors; - - if (!devmaj) - devidx = disk->first_minor / perdev_minors; + int devidx = disk->first_minor / perdev_minors; return devidx; } @@ -2162,6 +2158,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card, md->disk->queue = md->queue.queue; md->disk->driverfs_dev = parent; set_disk_ro(md->disk, md->read_only || default_ro); + md->disk->flags = GENHD_FL_EXT_DEVT; if (area_type & (MMC_BLK_DATA_AREA_RPMB | MMC_BLK_DATA_AREA_BOOT)) md->disk->flags |= GENHD_FL_NO_PART_SCAN;