linux/block/partitions, branch v3.12.14

block/partitions/efi.c: treat size mismatch as a warning, not an error

2013-10-17T04:35:53Z

In commit 27a7c642174e ("partitions/efi: account for pmbr size in lba") we started treating bad sizes in lba field of the partition that has the 0xEE (GPT protective) as errors. However, we may run into these "bad sizes" in the real world if someone uses dd to copy an image from a smaller disk to a bigger disk. Since this case used to work (even without using force_gpt), keep it working and treat the size mismatch as a warning instead of an error. Reported-by: Josh Triplett Reported-by: Sean Paul Signed-off-by: Doug Anderson Reviewed-by: Josh Triplett Acked-by: Davidlohr Bueso Tested-by: Artem Bityutskiy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

block: change config option name for cmdline partition parsing

2013-09-30T21:31:02Z

Recently commit bab55417b10c ("block: support embedded device command line partition") introduced CONFIG_CMDLINE_PARSER. However, that name is too generic and sounds like it enables/disables generic kernel boot arg processing, when it really is block specific. Before this option becomes a part of a full/final release, add the BLK_ prefix to it so that it is clear in absence of any other context that it is block specific. In addition, fix up the following less critical items: - help text was not really at all helpful. - index file for Documentation was not updated - add the new arg to Documentation/kernel-parameters.txt - clarify wording in source comments Signed-off-by: Paul Gortmaker Cc: Jens Axboe Cc: Cai Zhiyong Cc: Wei Yongjun Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: loosen check fot pmbr size in lba

2013-09-15T11:10:16Z

Matt found that commit 27a7c642174e ("partitions/efi: account for pmbr size in lba") caused his GPT formatted eMMC device not to boot. The reason is that this commit enforced Linux to always check the lesser of the whole disk or 2Tib for the pMBR size in LBA. While most disk partitioning tools out there create a pMBR with these characteristics, Microsoft does not, as it always sets the entry to the maximum 32-bit limitation - even though a drive may be smaller than that[1]. Loosen this check and only verify that the size is either the whole disk or 0xFFFFFFFF. No tool in its right mind would set it to any value other than these. [1] http://thestarman.pcministry.com/asm/mbr/GPT.htm#GPTPT Reported-and-tested-by: Matt Porter Signed-off-by: Davidlohr Bueso Signed-off-by: Linus Torvalds

block/partitions/efi.c: consistently use pr_foo()

2013-09-11T22:59:19Z

Cc: Davidlohr Bueso Cc: Karel Zak Cc: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: some style cleanups

2013-09-11T22:59:19Z

Trivial coding style cleanups - still plenty left. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: delete annoying emacs style comments

2013-09-11T22:59:18Z

I love emacs, but these settings for coding style are annoying when trying to open the efi.h file. More important, we already have checkpatch for that. Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: compare first and last usable LBAs

2013-09-11T22:59:18Z

When verifying GPT header integrity, make sure that first usable LBA is smaller than last usable LBA. Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: account for pmbr size in lba

2013-09-11T22:59:17Z

The partition that has the 0xEE (GPT protective), must have the size in lba field set to the lesser of the size of the disk minus one or 0xFFFFFFFF for larger disks. Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: detect hybrid MBRs

2013-09-11T22:59:16Z

One of the biggest problems with GPT is compatibility with older, non-GPT systems. The problem is addressed by creating hybrid mbrs, an extension, or variant, of the traditional protective mbr. This contains, apart from the 0xEE partition, up three additional primary partitions that point to the same space marked by up to three GPT partitions. The result is that legacy OSs can see the three required MBR partitions and at the same time ignore the GPT-aware partitions that protect the GPT structures. While hybrid MBRs are hacks, workarounds and simply not part of the GPT standard, they do exist and we have no way around them. For instance, by default, OSX creates a hybrid scheme when using multi-OS booting. In order for Linux to properly discover protective MBRs, it must be made aware of devices that have hybrid MBRs. No functionality is changed by this patch, just a debug message informing the user of the MBR scheme that is being used. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

partitions/efi: do not require gpt partition to begin at sector 1

2013-09-11T22:59:16Z

When detecting a valid protective MBR, the Linux kernel isn't picky about the partition (1-4) the 0xEE is at, but, unlike other operating systems, it does require it to begin at the second sector (sector 1). This check, apart from it not being enforced by UEFI, and causing Linux to potentially fail to detect any *valid* partitions on the disk, can present problems when dealing with hybrid MBRs[1]. For compatibility reasons, if the first partition is hybridized, the 0xEE partition must be small enough to ensure that it only protects the GPT data structures - as opposed to the the whole disk in a protective MBR. This problem is very well described by Rod Smith[1]: where MBR-only partitioning programs (such as older versions of fdisk) can see some of the disk space as unallocated, thus loosing the purpose of the 0xEE partition's protection of GPT data structures. By dropping this check, this patch enables Linux to be more flexible when probing for GPT disklabels. [1] http://www.rodsbooks.com/gdisk/hybrid.html#reactions Signed-off-by: Davidlohr Bueso Reviewed-by: Karel Zak Acked-by: Matt Fleming Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds