OpenCloudOS-Kernel/include/linux/buffer_head.h

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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 22:07:57 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* include/linux/buffer_head.h
*
* Everything to do with buffer_heads.
*/
#ifndef _LINUX_BUFFER_HEAD_H
#define _LINUX_BUFFER_HEAD_H
#include <linux/types.h>
#include <linux/blk_types.h>
#include <linux/fs.h>
#include <linux/linkage.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/atomic.h>
[PATCH] BLOCK: Make it possible to disable the block layer [try #6] Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-10-01 02:45:40 +08:00
#ifdef CONFIG_BLOCK
enum bh_state_bits {
BH_Uptodate, /* Contains valid data */
BH_Dirty, /* Is dirty */
BH_Lock, /* Is locked */
BH_Req, /* Has been submitted for I/O */
BH_Mapped, /* Has a disk mapping */
BH_New, /* Disk mapping was newly created by get_block */
BH_Async_Read, /* Is under end_buffer_async_read I/O */
BH_Async_Write, /* Is under end_buffer_async_write I/O */
BH_Delay, /* Buffer is not yet allocated on disk */
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
BH_Unwritten, /* Buffer is allocated on disk but not written */
block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-25 17:24:35 +08:00
BH_Quiet, /* Buffer Error Prinks to be quiet */
BH_Meta, /* Buffer contains metadata */
BH_Prio, /* Buffer should be submitted with REQ_PRIO */
BH_Defer_Completion, /* Defer AIO completion to workqueue */
BH_PrivateStart,/* not a state bit, but the first bit available
* for private allocation by other entities
*/
};
mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01 20:29:47 +08:00
#define MAX_BUF_PER_PAGE (PAGE_SIZE / 512)
struct page;
struct buffer_head;
struct address_space;
typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
/*
* Historically, a buffer_head was used to map a single block
* within a page, and of course as the unit of I/O through the
* filesystem and block layers. Nowadays the basic I/O unit
* is the bio, and buffer_heads are used for extracting block
* mappings (via a get_block_t call), for tracking state within
* a page (via a page_mapping) and for wrapping bio submission
* for backward compatibility reasons (e.g. submit_bh).
*/
struct buffer_head {
unsigned long b_state; /* buffer state bitmap (see above) */
struct buffer_head *b_this_page;/* circular list of page's buffers */
union {
struct page *b_page; /* the page this bh is mapped to */
struct folio *b_folio; /* the folio this bh is mapped to */
};
sector_t b_blocknr; /* start block number */
size_t b_size; /* size of mapping */
char *b_data; /* pointer to data within the page */
struct block_device *b_bdev;
bh_end_io_t *b_end_io; /* I/O completion */
void *b_private; /* reserved for b_end_io */
struct list_head b_assoc_buffers; /* associated with another mapping */
struct address_space *b_assoc_map; /* mapping this buffer is
associated with */
atomic_t b_count; /* users using this buffer_head */
spinlock_t b_uptodate_lock; /* Used by the first bh in a page, to
* serialise IO completion of other
* buffers in the page */
};
/*
* macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
* and buffer_foo() functions.
* To avoid reset buffer flags that are already set, because that causes
* a costly cache line transition, check the flag first.
*/
#define BUFFER_FNS(bit, name) \
static __always_inline void set_buffer_##name(struct buffer_head *bh) \
{ \
if (!test_bit(BH_##bit, &(bh)->b_state)) \
set_bit(BH_##bit, &(bh)->b_state); \
} \
static __always_inline void clear_buffer_##name(struct buffer_head *bh) \
{ \
clear_bit(BH_##bit, &(bh)->b_state); \
} \
static __always_inline int buffer_##name(const struct buffer_head *bh) \
{ \
return test_bit(BH_##bit, &(bh)->b_state); \
}
/*
* test_set_buffer_foo() and test_clear_buffer_foo()
*/
#define TAS_BUFFER_FNS(bit, name) \
static __always_inline int test_set_buffer_##name(struct buffer_head *bh) \
{ \
return test_and_set_bit(BH_##bit, &(bh)->b_state); \
} \
static __always_inline int test_clear_buffer_##name(struct buffer_head *bh) \
{ \
return test_and_clear_bit(BH_##bit, &(bh)->b_state); \
} \
/*
* Emit the buffer bitops functions. Note that there are also functions
* of the form "mark_buffer_foo()". These are higher-level functions which
* do something in addition to setting a b_state bit.
*/
BUFFER_FNS(Dirty, dirty)
TAS_BUFFER_FNS(Dirty, dirty)
BUFFER_FNS(Lock, locked)
BUFFER_FNS(Req, req)
TAS_BUFFER_FNS(Req, req)
BUFFER_FNS(Mapped, mapped)
BUFFER_FNS(New, new)
BUFFER_FNS(Async_Read, async_read)
BUFFER_FNS(Async_Write, async_write)
BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
BUFFER_FNS(Unwritten, unwritten)
BUFFER_FNS(Meta, meta)
BUFFER_FNS(Prio, prio)
BUFFER_FNS(Defer_Completion, defer_completion)
static __always_inline void set_buffer_uptodate(struct buffer_head *bh)
{
fs: only do a memory barrier for the first set_buffer_uptodate() Commit d4252071b97d ("add barriers to buffer_uptodate and set_buffer_uptodate") added proper memory barriers to the buffer head BH_Uptodate bit, so that anybody who tests a buffer for being up-to-date will be guaranteed to actually see initialized state. However, that commit didn't _just_ add the memory barrier, it also ended up dropping the "was it already set" logic that the BUFFER_FNS() macro had. That's conceptually the right thing for a generic "this is a memory barrier" operation, but in the case of the buffer contents, we really only care about the memory barrier for the _first_ time we set the bit, in that the only memory ordering protection we need is to avoid anybody seeing uninitialized memory contents. Any other access ordering wouldn't be about the BH_Uptodate bit anyway, and would require some other proper lock (typically BH_Lock or the folio lock). A reader that races with somebody invalidating the buffer head isn't an issue wrt the memory ordering, it's a serialization issue. Now, you'd think that the buffer head operations don't matter in this day and age (and I certainly thought so), but apparently some loads still end up being heavy users of buffer heads. In particular, the kernel test robot reported that not having this bit access optimization in place caused a noticeable direct IO performance regression on ext4: fxmark.ssd_ext4_no_jnl_DWTL_54_directio.works/sec -26.5% regression although you presumably need a fast disk and a lot of cores to actually notice. Link: https://lore.kernel.org/all/Yw8L7HTZ%2FdE2%2Fo9C@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Fengwei Yin <fengwei.yin@intel.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-09-01 00:46:12 +08:00
/*
* If somebody else already set this uptodate, they will
* have done the memory barrier, and a reader will thus
* see *some* valid buffer state.
*
* Any other serialization (with IO errors or whatever that
* might clear the bit) has to come from other state (eg BH_Lock).
*/
if (test_bit(BH_Uptodate, &bh->b_state))
return;
/*
* make it consistent with folio_mark_uptodate
* pairs with smp_load_acquire in buffer_uptodate
*/
smp_mb__before_atomic();
set_bit(BH_Uptodate, &bh->b_state);
}
static __always_inline void clear_buffer_uptodate(struct buffer_head *bh)
{
clear_bit(BH_Uptodate, &bh->b_state);
}
static __always_inline int buffer_uptodate(const struct buffer_head *bh)
{
/*
* make it consistent with folio_test_uptodate
* pairs with smp_mb__before_atomic in set_buffer_uptodate
*/
return test_bit_acquire(BH_Uptodate, &bh->b_state);
}
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
/* If we *know* page->private refers to buffer_heads */
#define page_buffers(page) \
({ \
[PATCH] mm: split page table lock Christoph Lameter demonstrated very poor scalability on the SGI 512-way, with a many-threaded application which concurrently initializes different parts of a large anonymous area. This patch corrects that, by using a separate spinlock per page table page, to guard the page table entries in that page, instead of using the mm's single page_table_lock. (But even then, page_table_lock is still used to guard page table allocation, and anon_vma allocation.) In this implementation, the spinlock is tucked inside the struct page of the page table page: with a BUILD_BUG_ON in case it overflows - which it would in the case of 32-bit PA-RISC with spinlock debugging enabled. Splitting the lock is not quite for free: another cacheline access. Ideally, I suppose we would use split ptlock only for multi-threaded processes on multi-cpu machines; but deciding that dynamically would have its own costs. So for now enable it by config, at some number of cpus - since the Kconfig language doesn't support inequalities, let preprocessor compare that with NR_CPUS. But I don't think it's worth being user-configurable: for good testing of both split and unsplit configs, split now at 4 cpus, and perhaps change that to 8 later. There is a benefit even for singly threaded processes: kswapd can be attacking one part of the mm while another part is busy faulting. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 09:16:40 +08:00
BUG_ON(!PagePrivate(page)); \
((struct buffer_head *)page_private(page)); \
})
#define page_has_buffers(page) PagePrivate(page)
#define folio_buffers(folio) folio_get_private(folio)
void buffer_check_dirty_writeback(struct folio *folio,
mm: vmscan: take page buffers dirty and locked state into account Page reclaim keeps track of dirty and under writeback pages and uses it to determine if wait_iff_congested() should stall or if kswapd should begin writing back pages. This fails to account for buffer pages that can be under writeback but not PageWriteback which is the case for filesystems like ext3 ordered mode. Furthermore, PageDirty buffer pages can have all the buffers clean and writepage does no IO so it should not be accounted as congested. This patch adds an address_space operation that filesystems may optionally use to check if a page is really dirty or really under writeback. An implementation is provided for for buffer_heads is added and used for block operations and ext3 in ordered mode. By default the page flags are obeyed. Credit goes to Jan Kara for identifying that the page flags alone are not sufficient for ext3 and sanity checking a number of ideas on how the problem could be addressed. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Zlatko Calusic <zcalusic@bitsync.net> Cc: dormando <dormando@rydia.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-04 06:02:05 +08:00
bool *dirty, bool *writeback);
/*
* Declarations
*/
void mark_buffer_dirty(struct buffer_head *bh);
void mark_buffer_write_io_error(struct buffer_head *bh);
void touch_buffer(struct buffer_head *bh);
void set_bh_page(struct buffer_head *bh,
struct page *page, unsigned long offset);
void folio_set_bh(struct buffer_head *bh, struct folio *folio,
unsigned long offset);
bool try_to_free_buffers(struct folio *);
struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size,
bool retry);
struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
bool retry);
void create_empty_buffers(struct page *, unsigned long,
unsigned long b_state);
void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize,
unsigned long b_state);
void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
void end_buffer_async_write(struct buffer_head *bh, int uptodate);
/* Things to do with buffers at mapping->private_list */
void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
int inode_has_buffers(struct inode *);
void invalidate_inode_buffers(struct inode *);
int remove_inode_buffers(struct inode *inode);
int sync_mapping_buffers(struct address_space *mapping);
void clean_bdev_aliases(struct block_device *bdev, sector_t block,
sector_t len);
static inline void clean_bdev_bh_alias(struct buffer_head *bh)
{
clean_bdev_aliases(bh->b_bdev, bh->b_blocknr, 1);
}
void mark_buffer_async_write(struct buffer_head *bh);
void __wait_on_buffer(struct buffer_head *);
wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
unsigned size);
struct buffer_head *__getblk_gfp(struct block_device *bdev, sector_t block,
unsigned size, gfp_t gfp);
void __brelse(struct buffer_head *);
void __bforget(struct buffer_head *);
void __breadahead(struct block_device *, sector_t block, unsigned int size);
struct buffer_head *__bread_gfp(struct block_device *,
sector_t block, unsigned size, gfp_t gfp);
void invalidate_bh_lrus(void);
void invalidate_bh_lrus_cpu(void);
bool has_bh_in_lru(int cpu, void *dummy);
struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
void free_buffer_head(struct buffer_head * bh);
void unlock_buffer(struct buffer_head *bh);
void __lock_buffer(struct buffer_head *bh);
int sync_dirty_buffer(struct buffer_head *bh);
int __sync_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
void write_dirty_buffer(struct buffer_head *bh, blk_opf_t op_flags);
void submit_bh(blk_opf_t, struct buffer_head *);
void write_boundary_block(struct block_device *bdev,
sector_t bblock, unsigned blocksize);
int bh_uptodate_or_lock(struct buffer_head *bh);
int __bh_read(struct buffer_head *bh, blk_opf_t op_flags, bool wait);
void __bh_read_batch(int nr, struct buffer_head *bhs[],
blk_opf_t op_flags, bool force_lock);
extern int buffer_heads_over_limit;
/*
* Generic address_space_operations implementations for buffer_head-backed
* address_spaces.
*/
void block_invalidate_folio(struct folio *folio, size_t offset, size_t length);
int block_write_full_page(struct page *page, get_block_t *get_block,
struct writeback_control *wbc);
int __block_write_full_page(struct inode *inode, struct page *page,
get_block_t *get_block, struct writeback_control *wbc,
bh_end_io_t *handler);
int block_read_full_folio(struct folio *, get_block_t *);
bool block_is_partially_uptodate(struct folio *, size_t from, size_t count);
int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
struct page **pagep, get_block_t *get_block);
int __block_write_begin(struct page *page, loff_t pos, unsigned len,
get_block_t *get_block);
int block_write_end(struct file *, struct address_space *,
loff_t, unsigned, unsigned,
struct page *, void *);
int generic_write_end(struct file *, struct address_space *,
loff_t, unsigned, unsigned,
struct page *, void *);
void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
void clean_page_buffers(struct page *page);
int cont_write_begin(struct file *, struct address_space *, loff_t,
unsigned, struct page **, void **,
get_block_t *, loff_t *);
int generic_cont_expand_simple(struct inode *inode, loff_t size);
int block_commit_write(struct page *page, unsigned from, unsigned to);
int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block);
/* Convert errno to return value from ->page_mkwrite() call */
static inline vm_fault_t block_page_mkwrite_return(int err)
{
if (err == 0)
return VM_FAULT_LOCKED;
if (err == -EFAULT || err == -EAGAIN)
return VM_FAULT_NOPAGE;
if (err == -ENOMEM)
return VM_FAULT_OOM;
/* -ENOSPC, -EDQUOT, -EIO ... */
return VM_FAULT_SIGBUS;
}
sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
int block_truncate_page(struct address_space *, loff_t, get_block_t *);
#ifdef CONFIG_MIGRATION
extern int buffer_migrate_folio(struct address_space *,
struct folio *dst, struct folio *src, enum migrate_mode);
extern int buffer_migrate_folio_norefs(struct address_space *,
struct folio *dst, struct folio *src, enum migrate_mode);
#else
#define buffer_migrate_folio NULL
#define buffer_migrate_folio_norefs NULL
#endif
void buffer_init(void);
/*
* inline definitions
*/
static inline void get_bh(struct buffer_head *bh)
{
atomic_inc(&bh->b_count);
}
static inline void put_bh(struct buffer_head *bh)
{
smp_mb__before_atomic();
atomic_dec(&bh->b_count);
}
static inline void brelse(struct buffer_head *bh)
{
if (bh)
__brelse(bh);
}
static inline void bforget(struct buffer_head *bh)
{
if (bh)
__bforget(bh);
}
static inline struct buffer_head *
sb_bread(struct super_block *sb, sector_t block)
{
return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE);
}
static inline struct buffer_head *
sb_bread_unmovable(struct super_block *sb, sector_t block)
{
return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, 0);
}
static inline void
sb_breadahead(struct super_block *sb, sector_t block)
{
__breadahead(sb->s_bdev, block, sb->s_blocksize);
}
static inline struct buffer_head *
sb_getblk(struct super_block *sb, sector_t block)
{
return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE);
}
static inline struct buffer_head *
sb_getblk_gfp(struct super_block *sb, sector_t block, gfp_t gfp)
{
return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, gfp);
}
static inline struct buffer_head *
sb_find_get_block(struct super_block *sb, sector_t block)
{
return __find_get_block(sb->s_bdev, block, sb->s_blocksize);
}
static inline void
map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
{
set_buffer_mapped(bh);
bh->b_bdev = sb->s_bdev;
bh->b_blocknr = block;
bh->b_size = sb->s_blocksize;
}
static inline void wait_on_buffer(struct buffer_head *bh)
{
might_sleep();
if (buffer_locked(bh))
__wait_on_buffer(bh);
}
static inline int trylock_buffer(struct buffer_head *bh)
{
return likely(!test_and_set_bit_lock(BH_Lock, &bh->b_state));
}
static inline void lock_buffer(struct buffer_head *bh)
{
might_sleep();
if (!trylock_buffer(bh))
__lock_buffer(bh);
}
static inline struct buffer_head *getblk_unmovable(struct block_device *bdev,
sector_t block,
unsigned size)
{
return __getblk_gfp(bdev, block, size, 0);
}
static inline struct buffer_head *__getblk(struct block_device *bdev,
sector_t block,
unsigned size)
{
return __getblk_gfp(bdev, block, size, __GFP_MOVABLE);
}
static inline void bh_readahead(struct buffer_head *bh, blk_opf_t op_flags)
{
if (!buffer_uptodate(bh) && trylock_buffer(bh)) {
if (!buffer_uptodate(bh))
__bh_read(bh, op_flags, false);
else
unlock_buffer(bh);
}
}
static inline void bh_read_nowait(struct buffer_head *bh, blk_opf_t op_flags)
{
if (!bh_uptodate_or_lock(bh))
__bh_read(bh, op_flags, false);
}
/* Returns 1 if buffer uptodated, 0 on success, and -EIO on error. */
static inline int bh_read(struct buffer_head *bh, blk_opf_t op_flags)
{
if (bh_uptodate_or_lock(bh))
return 1;
return __bh_read(bh, op_flags, true);
}
static inline void bh_read_batch(int nr, struct buffer_head *bhs[])
{
__bh_read_batch(nr, bhs, 0, true);
}
static inline void bh_readahead_batch(int nr, struct buffer_head *bhs[],
blk_opf_t op_flags)
{
__bh_read_batch(nr, bhs, op_flags, false);
}
/**
* __bread() - reads a specified block and returns the bh
* @bdev: the block_device to read from
* @block: number of block
* @size: size (in bytes) to read
*
* Reads a specified block, and returns buffer head that contains it.
* The page cache is allocated from movable area so that it can be migrated.
* It returns NULL if the block was unreadable.
*/
static inline struct buffer_head *
__bread(struct block_device *bdev, sector_t block, unsigned size)
{
return __bread_gfp(bdev, block, size, __GFP_MOVABLE);
}
bool block_dirty_folio(struct address_space *mapping, struct folio *folio);
[PATCH] BLOCK: Make it possible to disable the block layer [try #6] Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-10-01 02:45:40 +08:00
#else /* CONFIG_BLOCK */
static inline void buffer_init(void) {}
static inline bool try_to_free_buffers(struct folio *folio) { return true; }
[PATCH] BLOCK: Make it possible to disable the block layer [try #6] Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-10-01 02:45:40 +08:00
static inline int inode_has_buffers(struct inode *inode) { return 0; }
static inline void invalidate_inode_buffers(struct inode *inode) {}
static inline int remove_inode_buffers(struct inode *inode) { return 1; }
static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
static inline void invalidate_bh_lrus_cpu(void) {}
static inline bool has_bh_in_lru(int cpu, void *dummy) { return false; }
#define buffer_heads_over_limit 0
[PATCH] BLOCK: Make it possible to disable the block layer [try #6] Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-10-01 02:45:40 +08:00
#endif /* CONFIG_BLOCK */
#endif /* _LINUX_BUFFER_HEAD_H */