![Greg Kroah-Hartman](/assets/img/avatar_default.png)
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>
643 lines
19 KiB
C
643 lines
19 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_PAGEMAP_H
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#define _LINUX_PAGEMAP_H
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/*
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* Copyright 1995 Linus Torvalds
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*/
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/list.h>
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#include <linux/highmem.h>
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#include <linux/compiler.h>
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#include <linux/uaccess.h>
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#include <linux/gfp.h>
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#include <linux/bitops.h>
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#include <linux/hardirq.h> /* for in_interrupt() */
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#include <linux/hugetlb_inline.h>
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/*
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* Bits in mapping->flags.
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*/
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enum mapping_flags {
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AS_EIO = 0, /* IO error on async write */
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AS_ENOSPC = 1, /* ENOSPC on async write */
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AS_MM_ALL_LOCKS = 2, /* under mm_take_all_locks() */
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AS_UNEVICTABLE = 3, /* e.g., ramdisk, SHM_LOCK */
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AS_EXITING = 4, /* final truncate in progress */
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/* writeback related tags are not used */
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AS_NO_WRITEBACK_TAGS = 5,
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};
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/**
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* mapping_set_error - record a writeback error in the address_space
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* @mapping - the mapping in which an error should be set
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* @error - the error to set in the mapping
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*
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* When writeback fails in some way, we must record that error so that
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* userspace can be informed when fsync and the like are called. We endeavor
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* to report errors on any file that was open at the time of the error. Some
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* internal callers also need to know when writeback errors have occurred.
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*
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* When a writeback error occurs, most filesystems will want to call
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* mapping_set_error to record the error in the mapping so that it can be
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* reported when the application calls fsync(2).
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*/
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static inline void mapping_set_error(struct address_space *mapping, int error)
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{
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if (likely(!error))
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return;
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/* Record in wb_err for checkers using errseq_t based tracking */
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filemap_set_wb_err(mapping, error);
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/* Record it in flags for now, for legacy callers */
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if (error == -ENOSPC)
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set_bit(AS_ENOSPC, &mapping->flags);
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else
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set_bit(AS_EIO, &mapping->flags);
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}
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static inline void mapping_set_unevictable(struct address_space *mapping)
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{
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set_bit(AS_UNEVICTABLE, &mapping->flags);
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}
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static inline void mapping_clear_unevictable(struct address_space *mapping)
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{
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clear_bit(AS_UNEVICTABLE, &mapping->flags);
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}
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static inline int mapping_unevictable(struct address_space *mapping)
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{
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if (mapping)
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return test_bit(AS_UNEVICTABLE, &mapping->flags);
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return !!mapping;
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}
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static inline void mapping_set_exiting(struct address_space *mapping)
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{
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set_bit(AS_EXITING, &mapping->flags);
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}
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static inline int mapping_exiting(struct address_space *mapping)
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{
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return test_bit(AS_EXITING, &mapping->flags);
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}
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static inline void mapping_set_no_writeback_tags(struct address_space *mapping)
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{
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set_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
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}
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static inline int mapping_use_writeback_tags(struct address_space *mapping)
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{
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return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
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}
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static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
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{
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return mapping->gfp_mask;
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}
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/* Restricts the given gfp_mask to what the mapping allows. */
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static inline gfp_t mapping_gfp_constraint(struct address_space *mapping,
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gfp_t gfp_mask)
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{
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return mapping_gfp_mask(mapping) & gfp_mask;
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}
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/*
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* This is non-atomic. Only to be used before the mapping is activated.
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* Probably needs a barrier...
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*/
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static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
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{
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m->gfp_mask = mask;
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}
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void release_pages(struct page **pages, int nr, bool cold);
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/*
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* speculatively take a reference to a page.
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* If the page is free (_refcount == 0), then _refcount is untouched, and 0
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* is returned. Otherwise, _refcount is incremented by 1 and 1 is returned.
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*
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* This function must be called inside the same rcu_read_lock() section as has
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* been used to lookup the page in the pagecache radix-tree (or page table):
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* this allows allocators to use a synchronize_rcu() to stabilize _refcount.
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*
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* Unless an RCU grace period has passed, the count of all pages coming out
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* of the allocator must be considered unstable. page_count may return higher
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* than expected, and put_page must be able to do the right thing when the
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* page has been finished with, no matter what it is subsequently allocated
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* for (because put_page is what is used here to drop an invalid speculative
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* reference).
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*
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* This is the interesting part of the lockless pagecache (and lockless
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* get_user_pages) locking protocol, where the lookup-side (eg. find_get_page)
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* has the following pattern:
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* 1. find page in radix tree
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* 2. conditionally increment refcount
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* 3. check the page is still in pagecache (if no, goto 1)
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*
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* Remove-side that cares about stability of _refcount (eg. reclaim) has the
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* following (with tree_lock held for write):
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* A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg)
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* B. remove page from pagecache
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* C. free the page
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*
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* There are 2 critical interleavings that matter:
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* - 2 runs before A: in this case, A sees elevated refcount and bails out
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* - A runs before 2: in this case, 2 sees zero refcount and retries;
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* subsequently, B will complete and 1 will find no page, causing the
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* lookup to return NULL.
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*
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* It is possible that between 1 and 2, the page is removed then the exact same
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* page is inserted into the same position in pagecache. That's OK: the
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* old find_get_page using tree_lock could equally have run before or after
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* such a re-insertion, depending on order that locks are granted.
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*
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* Lookups racing against pagecache insertion isn't a big problem: either 1
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* will find the page or it will not. Likewise, the old find_get_page could run
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* either before the insertion or afterwards, depending on timing.
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*/
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static inline int page_cache_get_speculative(struct page *page)
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{
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#ifdef CONFIG_TINY_RCU
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# ifdef CONFIG_PREEMPT_COUNT
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VM_BUG_ON(!in_atomic() && !irqs_disabled());
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# endif
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/*
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* Preempt must be disabled here - we rely on rcu_read_lock doing
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* this for us.
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*
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* Pagecache won't be truncated from interrupt context, so if we have
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* found a page in the radix tree here, we have pinned its refcount by
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* disabling preempt, and hence no need for the "speculative get" that
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* SMP requires.
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*/
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VM_BUG_ON_PAGE(page_count(page) == 0, page);
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page_ref_inc(page);
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#else
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if (unlikely(!get_page_unless_zero(page))) {
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/*
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* Either the page has been freed, or will be freed.
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* In either case, retry here and the caller should
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* do the right thing (see comments above).
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*/
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return 0;
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}
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#endif
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VM_BUG_ON_PAGE(PageTail(page), page);
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return 1;
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}
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/*
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* Same as above, but add instead of inc (could just be merged)
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*/
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static inline int page_cache_add_speculative(struct page *page, int count)
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{
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VM_BUG_ON(in_interrupt());
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#if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU)
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# ifdef CONFIG_PREEMPT_COUNT
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VM_BUG_ON(!in_atomic() && !irqs_disabled());
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# endif
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VM_BUG_ON_PAGE(page_count(page) == 0, page);
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page_ref_add(page, count);
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#else
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if (unlikely(!page_ref_add_unless(page, count, 0)))
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return 0;
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#endif
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VM_BUG_ON_PAGE(PageCompound(page) && page != compound_head(page), page);
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return 1;
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}
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#ifdef CONFIG_NUMA
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extern struct page *__page_cache_alloc(gfp_t gfp);
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#else
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static inline struct page *__page_cache_alloc(gfp_t gfp)
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{
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return alloc_pages(gfp, 0);
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}
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#endif
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static inline struct page *page_cache_alloc(struct address_space *x)
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{
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return __page_cache_alloc(mapping_gfp_mask(x));
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}
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static inline struct page *page_cache_alloc_cold(struct address_space *x)
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{
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return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD);
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}
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static inline gfp_t readahead_gfp_mask(struct address_space *x)
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{
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return mapping_gfp_mask(x) |
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__GFP_COLD | __GFP_NORETRY | __GFP_NOWARN;
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}
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typedef int filler_t(void *, struct page *);
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pgoff_t page_cache_next_hole(struct address_space *mapping,
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pgoff_t index, unsigned long max_scan);
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pgoff_t page_cache_prev_hole(struct address_space *mapping,
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pgoff_t index, unsigned long max_scan);
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#define FGP_ACCESSED 0x00000001
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#define FGP_LOCK 0x00000002
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#define FGP_CREAT 0x00000004
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#define FGP_WRITE 0x00000008
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#define FGP_NOFS 0x00000010
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#define FGP_NOWAIT 0x00000020
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struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
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int fgp_flags, gfp_t cache_gfp_mask);
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/**
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* find_get_page - find and get a page reference
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* @mapping: the address_space to search
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* @offset: the page index
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned with an increased refcount.
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*
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* Otherwise, %NULL is returned.
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*/
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static inline struct page *find_get_page(struct address_space *mapping,
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pgoff_t offset)
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{
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return pagecache_get_page(mapping, offset, 0, 0);
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}
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static inline struct page *find_get_page_flags(struct address_space *mapping,
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pgoff_t offset, int fgp_flags)
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{
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return pagecache_get_page(mapping, offset, fgp_flags, 0);
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}
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/**
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* find_lock_page - locate, pin and lock a pagecache page
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* @mapping: the address_space to search
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* @offset: the page index
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned locked and with an increased
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* refcount.
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*
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* Otherwise, %NULL is returned.
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*
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* find_lock_page() may sleep.
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*/
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static inline struct page *find_lock_page(struct address_space *mapping,
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pgoff_t offset)
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{
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return pagecache_get_page(mapping, offset, FGP_LOCK, 0);
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}
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/**
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* find_or_create_page - locate or add a pagecache page
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* @mapping: the page's address_space
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* @index: the page's index into the mapping
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* @gfp_mask: page allocation mode
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned locked and with an increased
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* refcount.
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*
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* If the page is not present, a new page is allocated using @gfp_mask
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* and added to the page cache and the VM's LRU list. The page is
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* returned locked and with an increased refcount.
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*
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* On memory exhaustion, %NULL is returned.
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*
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* find_or_create_page() may sleep, even if @gfp_flags specifies an
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* atomic allocation!
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*/
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static inline struct page *find_or_create_page(struct address_space *mapping,
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pgoff_t offset, gfp_t gfp_mask)
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{
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return pagecache_get_page(mapping, offset,
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FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
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gfp_mask);
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}
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/**
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* grab_cache_page_nowait - returns locked page at given index in given cache
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* @mapping: target address_space
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* @index: the page index
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*
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* Same as grab_cache_page(), but do not wait if the page is unavailable.
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* This is intended for speculative data generators, where the data can
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* be regenerated if the page couldn't be grabbed. This routine should
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* be safe to call while holding the lock for another page.
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*
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* Clear __GFP_FS when allocating the page to avoid recursion into the fs
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* and deadlock against the caller's locked page.
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*/
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static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
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pgoff_t index)
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{
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return pagecache_get_page(mapping, index,
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FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
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mapping_gfp_mask(mapping));
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}
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struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
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struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
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unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
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unsigned int nr_entries, struct page **entries,
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pgoff_t *indices);
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unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
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pgoff_t end, unsigned int nr_pages,
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struct page **pages);
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static inline unsigned find_get_pages(struct address_space *mapping,
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pgoff_t *start, unsigned int nr_pages,
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struct page **pages)
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{
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return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages,
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pages);
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}
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unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
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unsigned int nr_pages, struct page **pages);
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unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
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int tag, unsigned int nr_pages, struct page **pages);
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unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
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int tag, unsigned int nr_entries,
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struct page **entries, pgoff_t *indices);
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struct page *grab_cache_page_write_begin(struct address_space *mapping,
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pgoff_t index, unsigned flags);
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/*
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* Returns locked page at given index in given cache, creating it if needed.
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*/
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static inline struct page *grab_cache_page(struct address_space *mapping,
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pgoff_t index)
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{
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return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
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}
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extern struct page * read_cache_page(struct address_space *mapping,
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pgoff_t index, filler_t *filler, void *data);
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extern struct page * read_cache_page_gfp(struct address_space *mapping,
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pgoff_t index, gfp_t gfp_mask);
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extern int read_cache_pages(struct address_space *mapping,
|
|
struct list_head *pages, filler_t *filler, void *data);
|
|
|
|
static inline struct page *read_mapping_page(struct address_space *mapping,
|
|
pgoff_t index, void *data)
|
|
{
|
|
filler_t *filler = (filler_t *)mapping->a_ops->readpage;
|
|
return read_cache_page(mapping, index, filler, data);
|
|
}
|
|
|
|
/*
|
|
* Get index of the page with in radix-tree
|
|
* (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
|
|
*/
|
|
static inline pgoff_t page_to_index(struct page *page)
|
|
{
|
|
pgoff_t pgoff;
|
|
|
|
if (likely(!PageTransTail(page)))
|
|
return page->index;
|
|
|
|
/*
|
|
* We don't initialize ->index for tail pages: calculate based on
|
|
* head page
|
|
*/
|
|
pgoff = compound_head(page)->index;
|
|
pgoff += page - compound_head(page);
|
|
return pgoff;
|
|
}
|
|
|
|
/*
|
|
* Get the offset in PAGE_SIZE.
|
|
* (TODO: hugepage should have ->index in PAGE_SIZE)
|
|
*/
|
|
static inline pgoff_t page_to_pgoff(struct page *page)
|
|
{
|
|
if (unlikely(PageHeadHuge(page)))
|
|
return page->index << compound_order(page);
|
|
|
|
return page_to_index(page);
|
|
}
|
|
|
|
/*
|
|
* Return byte-offset into filesystem object for page.
|
|
*/
|
|
static inline loff_t page_offset(struct page *page)
|
|
{
|
|
return ((loff_t)page->index) << PAGE_SHIFT;
|
|
}
|
|
|
|
static inline loff_t page_file_offset(struct page *page)
|
|
{
|
|
return ((loff_t)page_index(page)) << PAGE_SHIFT;
|
|
}
|
|
|
|
extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
|
|
unsigned long address);
|
|
|
|
static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
|
|
unsigned long address)
|
|
{
|
|
pgoff_t pgoff;
|
|
if (unlikely(is_vm_hugetlb_page(vma)))
|
|
return linear_hugepage_index(vma, address);
|
|
pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
|
|
pgoff += vma->vm_pgoff;
|
|
return pgoff;
|
|
}
|
|
|
|
extern void __lock_page(struct page *page);
|
|
extern int __lock_page_killable(struct page *page);
|
|
extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
|
|
unsigned int flags);
|
|
extern void unlock_page(struct page *page);
|
|
|
|
static inline int trylock_page(struct page *page)
|
|
{
|
|
page = compound_head(page);
|
|
return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
|
|
}
|
|
|
|
/*
|
|
* lock_page may only be called if we have the page's inode pinned.
|
|
*/
|
|
static inline void lock_page(struct page *page)
|
|
{
|
|
might_sleep();
|
|
if (!trylock_page(page))
|
|
__lock_page(page);
|
|
}
|
|
|
|
/*
|
|
* lock_page_killable is like lock_page but can be interrupted by fatal
|
|
* signals. It returns 0 if it locked the page and -EINTR if it was
|
|
* killed while waiting.
|
|
*/
|
|
static inline int lock_page_killable(struct page *page)
|
|
{
|
|
might_sleep();
|
|
if (!trylock_page(page))
|
|
return __lock_page_killable(page);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* lock_page_or_retry - Lock the page, unless this would block and the
|
|
* caller indicated that it can handle a retry.
|
|
*
|
|
* Return value and mmap_sem implications depend on flags; see
|
|
* __lock_page_or_retry().
|
|
*/
|
|
static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
|
|
unsigned int flags)
|
|
{
|
|
might_sleep();
|
|
return trylock_page(page) || __lock_page_or_retry(page, mm, flags);
|
|
}
|
|
|
|
/*
|
|
* This is exported only for wait_on_page_locked/wait_on_page_writeback, etc.,
|
|
* and should not be used directly.
|
|
*/
|
|
extern void wait_on_page_bit(struct page *page, int bit_nr);
|
|
extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
|
|
|
|
/*
|
|
* Wait for a page to be unlocked.
|
|
*
|
|
* This must be called with the caller "holding" the page,
|
|
* ie with increased "page->count" so that the page won't
|
|
* go away during the wait..
|
|
*/
|
|
static inline void wait_on_page_locked(struct page *page)
|
|
{
|
|
if (PageLocked(page))
|
|
wait_on_page_bit(compound_head(page), PG_locked);
|
|
}
|
|
|
|
static inline int wait_on_page_locked_killable(struct page *page)
|
|
{
|
|
if (!PageLocked(page))
|
|
return 0;
|
|
return wait_on_page_bit_killable(compound_head(page), PG_locked);
|
|
}
|
|
|
|
/*
|
|
* Wait for a page to complete writeback
|
|
*/
|
|
static inline void wait_on_page_writeback(struct page *page)
|
|
{
|
|
if (PageWriteback(page))
|
|
wait_on_page_bit(page, PG_writeback);
|
|
}
|
|
|
|
extern void end_page_writeback(struct page *page);
|
|
void wait_for_stable_page(struct page *page);
|
|
|
|
void page_endio(struct page *page, bool is_write, int err);
|
|
|
|
/*
|
|
* Add an arbitrary waiter to a page's wait queue
|
|
*/
|
|
extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
|
|
|
|
/*
|
|
* Fault everything in given userspace address range in.
|
|
*/
|
|
static inline int fault_in_pages_writeable(char __user *uaddr, int size)
|
|
{
|
|
char __user *end = uaddr + size - 1;
|
|
|
|
if (unlikely(size == 0))
|
|
return 0;
|
|
|
|
if (unlikely(uaddr > end))
|
|
return -EFAULT;
|
|
/*
|
|
* Writing zeroes into userspace here is OK, because we know that if
|
|
* the zero gets there, we'll be overwriting it.
|
|
*/
|
|
do {
|
|
if (unlikely(__put_user(0, uaddr) != 0))
|
|
return -EFAULT;
|
|
uaddr += PAGE_SIZE;
|
|
} while (uaddr <= end);
|
|
|
|
/* Check whether the range spilled into the next page. */
|
|
if (((unsigned long)uaddr & PAGE_MASK) ==
|
|
((unsigned long)end & PAGE_MASK))
|
|
return __put_user(0, end);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int fault_in_pages_readable(const char __user *uaddr, int size)
|
|
{
|
|
volatile char c;
|
|
const char __user *end = uaddr + size - 1;
|
|
|
|
if (unlikely(size == 0))
|
|
return 0;
|
|
|
|
if (unlikely(uaddr > end))
|
|
return -EFAULT;
|
|
|
|
do {
|
|
if (unlikely(__get_user(c, uaddr) != 0))
|
|
return -EFAULT;
|
|
uaddr += PAGE_SIZE;
|
|
} while (uaddr <= end);
|
|
|
|
/* Check whether the range spilled into the next page. */
|
|
if (((unsigned long)uaddr & PAGE_MASK) ==
|
|
((unsigned long)end & PAGE_MASK)) {
|
|
return __get_user(c, end);
|
|
}
|
|
|
|
(void)c;
|
|
return 0;
|
|
}
|
|
|
|
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp_mask);
|
|
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp_mask);
|
|
extern void delete_from_page_cache(struct page *page);
|
|
extern void __delete_from_page_cache(struct page *page, void *shadow);
|
|
int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
|
|
|
|
/*
|
|
* Like add_to_page_cache_locked, but used to add newly allocated pages:
|
|
* the page is new, so we can just run __SetPageLocked() against it.
|
|
*/
|
|
static inline int add_to_page_cache(struct page *page,
|
|
struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
|
|
{
|
|
int error;
|
|
|
|
__SetPageLocked(page);
|
|
error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
|
|
if (unlikely(error))
|
|
__ClearPageLocked(page);
|
|
return error;
|
|
}
|
|
|
|
static inline unsigned long dir_pages(struct inode *inode)
|
|
{
|
|
return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>
|
|
PAGE_SHIFT;
|
|
}
|
|
|
|
#endif /* _LINUX_PAGEMAP_H */
|