linux/drivers/scsi/scsicam.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* scsicam.c - SCSI CAM support functions, use for HDIO_GETGEO, etc.
*
* Copyright 1993, 1994 Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* drew@Colorado.EDU
* +1 (303) 786-7975
*
* For more information, please consult the SCSI-CAM draft.
*/
#include <linux/module.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/msdos_partition.h>
#include <asm/unaligned.h>
#include <scsi/scsicam.h>
/**
* scsi_bios_ptable - Read PC partition table out of first sector of device.
* @dev: from this device
*
* Description: Reads the first sector from the device and returns %0x42 bytes
* starting at offset %0x1be.
* Returns: partition table in kmalloc(GFP_KERNEL) memory, or NULL on error.
*/
unsigned char *scsi_bios_ptable(struct block_device *dev)
{
struct address_space *mapping = bdev_whole(dev)->bd_inode->i_mapping;
unsigned char *res = NULL;
struct page *page;
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
return NULL;
if (!PageError(page))
res = kmemdup(page_address(page) + 0x1be, 66, GFP_KERNEL);
put_page(page);
return res;
}
EXPORT_SYMBOL(scsi_bios_ptable);
/**
* scsi_partsize - Parse cylinders/heads/sectors from PC partition table
* @bdev: block device to parse
* @capacity: size of the disk in sectors
* @geom: output in form of [hds, cylinders, sectors]
*
* Determine the BIOS mapping/geometry used to create the partition
* table, storing the results in @geom.
*
* Returns: %false on failure, %true on success.
*/
bool scsi_partsize(struct block_device *bdev, sector_t capacity, int geom[3])
{
int cyl, ext_cyl, end_head, end_cyl, end_sector;
unsigned int logical_end, physical_end, ext_physical_end;
struct msdos_partition *p, *largest = NULL;
void *buf;
int ret = false;
buf = scsi_bios_ptable(bdev);
if (!buf)
return false;
if (*(unsigned short *) (buf + 64) == 0xAA55) {
int largest_cyl = -1, i;
for (i = 0, p = buf; i < 4; i++, p++) {
if (!p->sys_ind)
continue;
#ifdef DEBUG
printk("scsicam_bios_param : partition %d has system \n",
i);
#endif
cyl = p->cyl + ((p->sector & 0xc0) << 2);
if (cyl > largest_cyl) {
largest_cyl = cyl;
largest = p;
}
}
}
if (largest) {
end_cyl = largest->end_cyl + ((largest->end_sector & 0xc0) << 2);
end_head = largest->end_head;
end_sector = largest->end_sector & 0x3f;
if (end_head + 1 == 0 || end_sector == 0)
goto out_free_buf;
#ifdef DEBUG
printk("scsicam_bios_param : end at h = %d, c = %d, s = %d\n",
end_head, end_cyl, end_sector);
#endif
physical_end = end_cyl * (end_head + 1) * end_sector +
end_head * end_sector + end_sector;
/* This is the actual _sector_ number at the end */
logical_end = get_unaligned_le32(&largest->start_sect)
+ get_unaligned_le32(&largest->nr_sects);
/* This is for >1023 cylinders */
ext_cyl = (logical_end - (end_head * end_sector + end_sector))
/ (end_head + 1) / end_sector;
ext_physical_end = ext_cyl * (end_head + 1) * end_sector +
end_head * end_sector + end_sector;
#ifdef DEBUG
printk("scsicam_bios_param : logical_end=%d physical_end=%d ext_physical_end=%d ext_cyl=%d\n"
,logical_end, physical_end, ext_physical_end, ext_cyl);
#endif
if (logical_end == physical_end ||
(end_cyl == 1023 && ext_physical_end == logical_end)) {
geom[0] = end_head + 1;
geom[1] = end_sector;
geom[2] = (unsigned long)capacity /
((end_head + 1) * end_sector);
ret = true;
goto out_free_buf;
}
#ifdef DEBUG
printk("scsicam_bios_param : logical (%u) != physical (%u)\n",
logical_end, physical_end);
#endif
}
out_free_buf:
kfree(buf);
return ret;
}
EXPORT_SYMBOL(scsi_partsize);
/*
* Function : static int setsize(unsigned long capacity,unsigned int *cyls,
* unsigned int *hds, unsigned int *secs);
*
* Purpose : to determine a near-optimal int 0x13 mapping for a
* SCSI disk in terms of lost space of size capacity, storing
* the results in *cyls, *hds, and *secs.
*
* Returns : -1 on failure, 0 on success.
*
* Extracted from
*
* WORKING X3T9.2
* DRAFT 792D
* see http://www.t10.org/ftp/t10/drafts/cam/cam-r12b.pdf
*
* Revision 6
* 10-MAR-94
* Information technology -
* SCSI-2 Common access method
* transport and SCSI interface module
*
* ANNEX A :
*
* setsize() converts a read capacity value to int 13h
* head-cylinder-sector requirements. It minimizes the value for
* number of heads and maximizes the number of cylinders. This
* will support rather large disks before the number of heads
* will not fit in 4 bits (or 6 bits). This algorithm also
* minimizes the number of sectors that will be unused at the end
* of the disk while allowing for very large disks to be
* accommodated. This algorithm does not use physical geometry.
*/
static int setsize(unsigned long capacity, unsigned int *cyls, unsigned int *hds,
unsigned int *secs)
{
unsigned int rv = 0;
unsigned long heads, sectors, cylinders, temp;
cylinders = 1024L; /* Set number of cylinders to max */
sectors = 62L; /* Maximize sectors per track */
temp = cylinders * sectors; /* Compute divisor for heads */
heads = capacity / temp; /* Compute value for number of heads */
if (capacity % temp) { /* If no remainder, done! */
heads++; /* Else, increment number of heads */
temp = cylinders * heads; /* Compute divisor for sectors */
sectors = capacity / temp; /* Compute value for sectors per
track */
if (capacity % temp) { /* If no remainder, done! */
sectors++; /* Else, increment number of sectors */
temp = heads * sectors; /* Compute divisor for cylinders */
cylinders = capacity / temp; /* Compute number of cylinders */
}
}
if (cylinders == 0)
rv = (unsigned) -1; /* Give error if 0 cylinders */
*cyls = (unsigned int) cylinders; /* Stuff return values */
*secs = (unsigned int) sectors;
*hds = (unsigned int) heads;
return (rv);
}
/**
* scsicam_bios_param - Determine geometry of a disk in cylinders/heads/sectors.
* @bdev: which device
* @capacity: size of the disk in sectors
* @ip: return value: ip[0]=heads, ip[1]=sectors, ip[2]=cylinders
*
* Description : determine the BIOS mapping/geometry used for a drive in a
* SCSI-CAM system, storing the results in ip as required
* by the HDIO_GETGEO ioctl().
*
* Returns : -1 on failure, 0 on success.
*/
int scsicam_bios_param(struct block_device *bdev, sector_t capacity, int *ip)
{
u64 capacity64 = capacity; /* Suppress gcc warning */
int ret = 0;
/* try to infer mapping from partition table */
if (scsi_partsize(bdev, capacity, ip))
return 0;
if (capacity64 < (1ULL << 32)) {
/*
* Pick some standard mapping with at most 1024 cylinders, and
* at most 62 sectors per track - this works up to 7905 MB.
*/
ret = setsize((unsigned long)capacity, (unsigned int *)ip + 2,
(unsigned int *)ip + 0, (unsigned int *)ip + 1);
}
/*
* If something went wrong, then apparently we have to return a geometry
* with more than 1024 cylinders.
*/
if (ret || ip[0] > 255 || ip[1] > 63) {
if ((capacity >> 11) > 65534) {
ip[0] = 255;
ip[1] = 63;
} else {
ip[0] = 64;
ip[1] = 32;
}
if (capacity > 65535*63*255)
ip[2] = 65535;
else
ip[2] = (unsigned long)capacity / (ip[0] * ip[1]);
}
return 0;
}
EXPORT_SYMBOL(scsicam_bios_param);