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linux-next/fs/befs/datastream.c
Greg Kroah-Hartman b24413180f 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>
2017-11-02 11:10:55 +01:00

526 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/befs/datastream.c
*
* Copyright (C) 2001 Will Dyson <will_dyson@pobox.com>
*
* Based on portions of file.c by Makoto Kato <m_kato@ga2.so-net.ne.jp>
*
* Many thanks to Dominic Giampaolo, author of "Practical File System
* Design with the Be File System", for such a helpful book.
*
*/
#include <linux/kernel.h>
#include <linux/buffer_head.h>
#include <linux/string.h>
#include "befs.h"
#include "datastream.h"
#include "io.h"
const befs_inode_addr BAD_IADDR = { 0, 0, 0 };
static int befs_find_brun_direct(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno, befs_block_run *run);
static int befs_find_brun_indirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
befs_block_run *run);
static int befs_find_brun_dblindirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
befs_block_run *run);
/**
* befs_read_datastream - get buffer_head containing data, starting from pos.
* @sb: Filesystem superblock
* @ds: datastream to find data with
* @pos: start of data
* @off: offset of data in buffer_head->b_data
*
* Returns pointer to buffer_head containing data starting with offset @off,
* if you don't need to know offset just set @off = NULL.
*/
struct buffer_head *
befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
befs_off_t pos, uint *off)
{
struct buffer_head *bh;
befs_block_run run;
befs_blocknr_t block; /* block coresponding to pos */
befs_debug(sb, "---> %s %llu", __func__, pos);
block = pos >> BEFS_SB(sb)->block_shift;
if (off)
*off = pos - (block << BEFS_SB(sb)->block_shift);
if (befs_fblock2brun(sb, ds, block, &run) != BEFS_OK) {
befs_error(sb, "BeFS: Error finding disk addr of block %lu",
(unsigned long)block);
befs_debug(sb, "<--- %s ERROR", __func__);
return NULL;
}
bh = befs_bread_iaddr(sb, run);
if (!bh) {
befs_error(sb, "BeFS: Error reading block %lu from datastream",
(unsigned long)block);
return NULL;
}
befs_debug(sb, "<--- %s read data, starting at %llu", __func__, pos);
return bh;
}
/**
* befs_fblock2brun - give back block run for fblock
* @sb: the superblock
* @data: datastream to read from
* @fblock: the blocknumber with the file position to find
* @run: The found run is passed back through this pointer
*
* Takes a file position and gives back a brun who's starting block
* is block number fblock of the file.
*
* Returns BEFS_OK or BEFS_ERR.
*
* Calls specialized functions for each of the three possible
* datastream regions.
*/
int
befs_fblock2brun(struct super_block *sb, const befs_data_stream *data,
befs_blocknr_t fblock, befs_block_run *run)
{
int err;
befs_off_t pos = fblock << BEFS_SB(sb)->block_shift;
if (pos < data->max_direct_range) {
err = befs_find_brun_direct(sb, data, fblock, run);
} else if (pos < data->max_indirect_range) {
err = befs_find_brun_indirect(sb, data, fblock, run);
} else if (pos < data->max_double_indirect_range) {
err = befs_find_brun_dblindirect(sb, data, fblock, run);
} else {
befs_error(sb,
"befs_fblock2brun() was asked to find block %lu, "
"which is not mapped by the datastream\n",
(unsigned long)fblock);
err = BEFS_ERR;
}
return err;
}
/**
* befs_read_lsmylink - read long symlink from datastream.
* @sb: Filesystem superblock
* @ds: Datastream to read from
* @buff: Buffer in which to place long symlink data
* @len: Length of the long symlink in bytes
*
* Returns the number of bytes read
*/
size_t
befs_read_lsymlink(struct super_block *sb, const befs_data_stream *ds,
void *buff, befs_off_t len)
{
befs_off_t bytes_read = 0; /* bytes readed */
u16 plen;
struct buffer_head *bh;
befs_debug(sb, "---> %s length: %llu", __func__, len);
while (bytes_read < len) {
bh = befs_read_datastream(sb, ds, bytes_read, NULL);
if (!bh) {
befs_error(sb, "BeFS: Error reading datastream block "
"starting from %llu", bytes_read);
befs_debug(sb, "<--- %s ERROR", __func__);
return bytes_read;
}
plen = ((bytes_read + BEFS_SB(sb)->block_size) < len) ?
BEFS_SB(sb)->block_size : len - bytes_read;
memcpy(buff + bytes_read, bh->b_data, plen);
brelse(bh);
bytes_read += plen;
}
befs_debug(sb, "<--- %s read %u bytes", __func__, (unsigned int)
bytes_read);
return bytes_read;
}
/**
* befs_count_blocks - blocks used by a file
* @sb: Filesystem superblock
* @ds: Datastream of the file
*
* Counts the number of fs blocks that the file represented by
* inode occupies on the filesystem, counting both regular file
* data and filesystem metadata (and eventually attribute data
* when we support attributes)
*/
befs_blocknr_t
befs_count_blocks(struct super_block *sb, const befs_data_stream *ds)
{
befs_blocknr_t blocks;
befs_blocknr_t datablocks; /* File data blocks */
befs_blocknr_t metablocks; /* FS metadata blocks */
struct befs_sb_info *befs_sb = BEFS_SB(sb);
befs_debug(sb, "---> %s", __func__);
datablocks = ds->size >> befs_sb->block_shift;
if (ds->size & (befs_sb->block_size - 1))
datablocks += 1;
metablocks = 1; /* Start with 1 block for inode */
/* Size of indirect block */
if (ds->size > ds->max_direct_range)
metablocks += ds->indirect.len;
/*
* Double indir block, plus all the indirect blocks it maps.
* In the double-indirect range, all block runs of data are
* BEFS_DBLINDIR_BRUN_LEN blocks long. Therefore, we know
* how many data block runs are in the double-indirect region,
* and from that we know how many indirect blocks it takes to
* map them. We assume that the indirect blocks are also
* BEFS_DBLINDIR_BRUN_LEN blocks long.
*/
if (ds->size > ds->max_indirect_range && ds->max_indirect_range != 0) {
uint dbl_bytes;
uint dbl_bruns;
uint indirblocks;
dbl_bytes =
ds->max_double_indirect_range - ds->max_indirect_range;
dbl_bruns =
dbl_bytes / (befs_sb->block_size * BEFS_DBLINDIR_BRUN_LEN);
indirblocks = dbl_bruns / befs_iaddrs_per_block(sb);
metablocks += ds->double_indirect.len;
metablocks += indirblocks;
}
blocks = datablocks + metablocks;
befs_debug(sb, "<--- %s %u blocks", __func__, (unsigned int)blocks);
return blocks;
}
/**
* befs_find_brun_direct - find a direct block run in the datastream
* @sb: the superblock
* @data: the datastream
* @blockno: the blocknumber to find
* @run: The found run is passed back through this pointer
*
* Finds the block run that starts at file block number blockno
* in the file represented by the datastream data, if that
* blockno is in the direct region of the datastream.
*
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
* otherwise.
*
* Algorithm:
* Linear search. Checks each element of array[] to see if it
* contains the blockno-th filesystem block. This is necessary
* because the block runs map variable amounts of data. Simply
* keeps a count of the number of blocks searched so far (sum),
* incrementing this by the length of each block run as we come
* across it. Adds sum to *count before returning (this is so
* you can search multiple arrays that are logicaly one array,
* as in the indirect region code).
*
* When/if blockno is found, if blockno is inside of a block
* run as stored on disk, we offset the start and length members
* of the block run, so that blockno is the start and len is
* still valid (the run ends in the same place).
*/
static int
befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
befs_blocknr_t blockno, befs_block_run *run)
{
int i;
const befs_block_run *array = data->direct;
befs_blocknr_t sum;
befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
for (i = 0, sum = 0; i < BEFS_NUM_DIRECT_BLOCKS;
sum += array[i].len, i++) {
if (blockno >= sum && blockno < sum + (array[i].len)) {
int offset = blockno - sum;
run->allocation_group = array[i].allocation_group;
run->start = array[i].start + offset;
run->len = array[i].len - offset;
befs_debug(sb, "---> %s, "
"found %lu at direct[%d]", __func__,
(unsigned long)blockno, i);
return BEFS_OK;
}
}
befs_error(sb, "%s failed to find file block %lu", __func__,
(unsigned long)blockno);
befs_debug(sb, "---> %s ERROR", __func__);
return BEFS_ERR;
}
/**
* befs_find_brun_indirect - find a block run in the datastream
* @sb: the superblock
* @data: the datastream
* @blockno: the blocknumber to find
* @run: The found run is passed back through this pointer
*
* Finds the block run that starts at file block number blockno
* in the file represented by the datastream data, if that
* blockno is in the indirect region of the datastream.
*
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
* otherwise.
*
* Algorithm:
* For each block in the indirect run of the datastream, read
* it in and search through it for search_blk.
*
* XXX:
* Really should check to make sure blockno is inside indirect
* region.
*/
static int
befs_find_brun_indirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
befs_block_run *run)
{
int i, j;
befs_blocknr_t sum = 0;
befs_blocknr_t indir_start_blk;
befs_blocknr_t search_blk;
struct buffer_head *indirblock;
befs_disk_block_run *array;
befs_block_run indirect = data->indirect;
befs_blocknr_t indirblockno = iaddr2blockno(sb, &indirect);
int arraylen = befs_iaddrs_per_block(sb);
befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
indir_start_blk = data->max_direct_range >> BEFS_SB(sb)->block_shift;
search_blk = blockno - indir_start_blk;
/* Examine blocks of the indirect run one at a time */
for (i = 0; i < indirect.len; i++) {
indirblock = sb_bread(sb, indirblockno + i);
if (indirblock == NULL) {
befs_error(sb, "---> %s failed to read "
"disk block %lu from the indirect brun",
__func__, (unsigned long)indirblockno + i);
befs_debug(sb, "<--- %s ERROR", __func__);
return BEFS_ERR;
}
array = (befs_disk_block_run *) indirblock->b_data;
for (j = 0; j < arraylen; ++j) {
int len = fs16_to_cpu(sb, array[j].len);
if (search_blk >= sum && search_blk < sum + len) {
int offset = search_blk - sum;
run->allocation_group =
fs32_to_cpu(sb, array[j].allocation_group);
run->start =
fs16_to_cpu(sb, array[j].start) + offset;
run->len =
fs16_to_cpu(sb, array[j].len) - offset;
brelse(indirblock);
befs_debug(sb,
"<--- %s found file block "
"%lu at indirect[%d]", __func__,
(unsigned long)blockno,
j + (i * arraylen));
return BEFS_OK;
}
sum += len;
}
brelse(indirblock);
}
/* Only fallthrough is an error */
befs_error(sb, "BeFS: %s failed to find "
"file block %lu", __func__, (unsigned long)blockno);
befs_debug(sb, "<--- %s ERROR", __func__);
return BEFS_ERR;
}
/**
* befs_find_brun_dblindirect - find a block run in the datastream
* @sb: the superblock
* @data: the datastream
* @blockno: the blocknumber to find
* @run: The found run is passed back through this pointer
*
* Finds the block run that starts at file block number blockno
* in the file represented by the datastream data, if that
* blockno is in the double-indirect region of the datastream.
*
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
* otherwise.
*
* Algorithm:
* The block runs in the double-indirect region are different.
* They are always allocated 4 fs blocks at a time, so each
* block run maps a constant amount of file data. This means
* that we can directly calculate how many block runs into the
* double-indirect region we need to go to get to the one that
* maps a particular filesystem block.
*
* We do this in two stages. First we calculate which of the
* inode addresses in the double-indirect block will point us
* to the indirect block that contains the mapping for the data,
* then we calculate which of the inode addresses in that
* indirect block maps the data block we are after.
*
* Oh, and once we've done that, we actually read in the blocks
* that contain the inode addresses we calculated above. Even
* though the double-indirect run may be several blocks long,
* we can calculate which of those blocks will contain the index
* we are after and only read that one. We then follow it to
* the indirect block and perform a similar process to find
* the actual block run that maps the data block we are interested
* in.
*
* Then we offset the run as in befs_find_brun_array() and we are
* done.
*/
static int
befs_find_brun_dblindirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
befs_block_run *run)
{
int dblindir_indx;
int indir_indx;
int offset;
int dbl_which_block;
int which_block;
int dbl_block_indx;
int block_indx;
off_t dblindir_leftover;
befs_blocknr_t blockno_at_run_start;
struct buffer_head *dbl_indir_block;
struct buffer_head *indir_block;
befs_block_run indir_run;
befs_disk_inode_addr *iaddr_array;
befs_blocknr_t indir_start_blk =
data->max_indirect_range >> BEFS_SB(sb)->block_shift;
off_t dbl_indir_off = blockno - indir_start_blk;
/* number of data blocks mapped by each of the iaddrs in
* the indirect block pointed to by the double indirect block
*/
size_t iblklen = BEFS_DBLINDIR_BRUN_LEN;
/* number of data blocks mapped by each of the iaddrs in
* the double indirect block
*/
size_t diblklen = iblklen * befs_iaddrs_per_block(sb)
* BEFS_DBLINDIR_BRUN_LEN;
befs_debug(sb, "---> %s find %lu", __func__, (unsigned long)blockno);
/* First, discover which of the double_indir->indir blocks
* contains pos. Then figure out how much of pos that
* accounted for. Then discover which of the iaddrs in
* the indirect block contains pos.
*/
dblindir_indx = dbl_indir_off / diblklen;
dblindir_leftover = dbl_indir_off % diblklen;
indir_indx = dblindir_leftover / diblklen;
/* Read double indirect block */
dbl_which_block = dblindir_indx / befs_iaddrs_per_block(sb);
if (dbl_which_block > data->double_indirect.len) {
befs_error(sb, "The double-indirect index calculated by "
"%s, %d, is outside the range "
"of the double-indirect block", __func__,
dblindir_indx);
return BEFS_ERR;
}
dbl_indir_block =
sb_bread(sb, iaddr2blockno(sb, &data->double_indirect) +
dbl_which_block);
if (dbl_indir_block == NULL) {
befs_error(sb, "%s couldn't read the "
"double-indirect block at blockno %lu", __func__,
(unsigned long)
iaddr2blockno(sb, &data->double_indirect) +
dbl_which_block);
return BEFS_ERR;
}
dbl_block_indx =
dblindir_indx - (dbl_which_block * befs_iaddrs_per_block(sb));
iaddr_array = (befs_disk_inode_addr *) dbl_indir_block->b_data;
indir_run = fsrun_to_cpu(sb, iaddr_array[dbl_block_indx]);
brelse(dbl_indir_block);
/* Read indirect block */
which_block = indir_indx / befs_iaddrs_per_block(sb);
if (which_block > indir_run.len) {
befs_error(sb, "The indirect index calculated by "
"%s, %d, is outside the range "
"of the indirect block", __func__, indir_indx);
return BEFS_ERR;
}
indir_block =
sb_bread(sb, iaddr2blockno(sb, &indir_run) + which_block);
if (indir_block == NULL) {
befs_error(sb, "%s couldn't read the indirect block "
"at blockno %lu", __func__, (unsigned long)
iaddr2blockno(sb, &indir_run) + which_block);
return BEFS_ERR;
}
block_indx = indir_indx - (which_block * befs_iaddrs_per_block(sb));
iaddr_array = (befs_disk_inode_addr *) indir_block->b_data;
*run = fsrun_to_cpu(sb, iaddr_array[block_indx]);
brelse(indir_block);
blockno_at_run_start = indir_start_blk;
blockno_at_run_start += diblklen * dblindir_indx;
blockno_at_run_start += iblklen * indir_indx;
offset = blockno - blockno_at_run_start;
run->start += offset;
run->len -= offset;
befs_debug(sb, "Found file block %lu in double_indirect[%d][%d],"
" double_indirect_leftover = %lu", (unsigned long)
blockno, dblindir_indx, indir_indx, dblindir_leftover);
return BEFS_OK;
}
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