cregit-Linux how code gets into the kernel

Release 4.10 fs/ocfs2/buffer_head_io.c

Directory: fs/ocfs2
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * io.c
 *
 * Buffer cache handling
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/bio.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "inode.h"
#include "journal.h"
#include "uptodate.h"
#include "buffer_head_io.h"
#include "ocfs2_trace.h"

/*
 * Bits on bh->b_state used by ocfs2.
 *
 * These MUST be after the JBD2 bits.  Hence, we use BH_JBDPrivateStart.
 */

enum ocfs2_state_bits {
	
BH_NeedsValidate = BH_JBDPrivateStart,
};

/* Expand the magic b_state functions */
BUFFER_FNS(NeedsValidate, needs_validate);


int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh, struct ocfs2_caching_info *ci) { int ret = 0; trace_ocfs2_write_block((unsigned long long)bh->b_blocknr, ci); BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO); BUG_ON(buffer_jbd(bh)); /* No need to check for a soft readonly file system here. non * journalled writes are only ever done on system files which * can get modified during recovery even if read-only. */ if (ocfs2_is_hard_readonly(osb)) { ret = -EROFS; mlog_errno(ret); goto out; } ocfs2_metadata_cache_io_lock(ci); lock_buffer(bh); set_buffer_uptodate(bh); /* remove from dirty list before I/O. */ clear_buffer_dirty(bh); get_bh(bh); /* for end_buffer_write_sync() */ bh->b_end_io = end_buffer_write_sync; submit_bh(REQ_OP_WRITE, 0, bh); wait_on_buffer(bh); if (buffer_uptodate(bh)) { ocfs2_set_buffer_uptodate(ci, bh); } else { /* We don't need to remove the clustered uptodate * information for this bh as it's not marked locally * uptodate. */ ret = -EIO; mlog_errno(ret); } ocfs2_metadata_cache_io_unlock(ci); out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
mark fashehmark fasheh14486.75%120.00%
tao matao ma116.63%240.00%
joel beckerjoel becker84.82%120.00%
michael christiemichael christie31.81%120.00%
Total166100.00%5100.00%


int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block, unsigned int nr, struct buffer_head *bhs[]) { int status = 0; unsigned int i; struct buffer_head *bh; trace_ocfs2_read_blocks_sync((unsigned long long)block, nr); if (!nr) goto bail; for (i = 0 ; i < nr ; i++) { if (bhs[i] == NULL) { bhs[i] = sb_getblk(osb->sb, block++); if (bhs[i] == NULL) { status = -ENOMEM; mlog_errno(status); goto bail; } } bh = bhs[i]; if (buffer_jbd(bh)) { trace_ocfs2_read_blocks_sync_jbd( (unsigned long long)bh->b_blocknr); continue; } if (buffer_dirty(bh)) { /* This should probably be a BUG, or * at least return an error. */ mlog(ML_ERROR, "trying to sync read a dirty " "buffer! (blocknr = %llu), skipping\n", (unsigned long long)bh->b_blocknr); continue; } lock_buffer(bh); if (buffer_jbd(bh)) { #ifdef CATCH_BH_JBD_RACES mlog(ML_ERROR, "block %llu had the JBD bit set " "while I was in lock_buffer!", (unsigned long long)bh->b_blocknr); BUG(); #else unlock_buffer(bh); continue; #endif } clear_buffer_uptodate(bh); get_bh(bh); /* for end_buffer_read_sync() */ bh->b_end_io = end_buffer_read_sync; submit_bh(REQ_OP_READ, 0, bh); } for (i = nr; i > 0; i--) { bh = bhs[i - 1]; /* No need to wait on the buffer if it's managed by JBD. */ if (!buffer_jbd(bh)) wait_on_buffer(bh); if (!buffer_uptodate(bh)) { /* Status won't be cleared from here on out, * so we can safely record this and loop back * to cleanup the other buffers. */ status = -EIO; put_bh(bh); bhs[i - 1] = NULL; } } bail: return status; }

Contributors

PersonTokensPropCommitsCommitProp
joel beckerjoel becker29390.15%116.67%
tao matao ma134.00%116.67%
gang hegang he134.00%116.67%
michael christiemichael christie30.92%116.67%
mark fashehmark fasheh20.62%116.67%
rui xiangrui xiang10.31%116.67%
Total325100.00%6100.00%


int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr, struct buffer_head *bhs[], int flags, int (*validate)(struct super_block *sb, struct buffer_head *bh)) { int status = 0; int i, ignore_cache = 0; struct buffer_head *bh; struct super_block *sb = ocfs2_metadata_cache_get_super(ci); trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags); BUG_ON(!ci); BUG_ON((flags & OCFS2_BH_READAHEAD) && (flags & OCFS2_BH_IGNORE_CACHE)); if (bhs == NULL) { status = -EINVAL; mlog_errno(status); goto bail; } if (nr < 0) { mlog(ML_ERROR, "asked to read %d blocks!\n", nr); status = -EINVAL; mlog_errno(status); goto bail; } if (nr == 0) { status = 0; goto bail; } ocfs2_metadata_cache_io_lock(ci); for (i = 0 ; i < nr ; i++) { if (bhs[i] == NULL) { bhs[i] = sb_getblk(sb, block++); if (bhs[i] == NULL) { ocfs2_metadata_cache_io_unlock(ci); status = -ENOMEM; mlog_errno(status); goto bail; } } bh = bhs[i]; ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE); /* There are three read-ahead cases here which we need to * be concerned with. All three assume a buffer has * previously been submitted with OCFS2_BH_READAHEAD * and it hasn't yet completed I/O. * * 1) The current request is sync to disk. This rarely * happens these days, and never when performance * matters - the code can just wait on the buffer * lock and re-submit. * * 2) The current request is cached, but not * readahead. ocfs2_buffer_uptodate() will return * false anyway, so we'll wind up waiting on the * buffer lock to do I/O. We re-check the request * with after getting the lock to avoid a re-submit. * * 3) The current request is readahead (and so must * also be a caching one). We short circuit if the * buffer is locked (under I/O) and if it's in the * uptodate cache. The re-check from #2 catches the * case that the previous read-ahead completes just * before our is-it-in-flight check. */ if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) { trace_ocfs2_read_blocks_from_disk( (unsigned long long)bh->b_blocknr, (unsigned long long)ocfs2_metadata_cache_owner(ci)); /* We're using ignore_cache here to say * "go to disk" */ ignore_cache = 1; } trace_ocfs2_read_blocks_bh((unsigned long long)bh->b_blocknr, ignore_cache, buffer_jbd(bh), buffer_dirty(bh)); if (buffer_jbd(bh)) { continue; } if (ignore_cache) { if (buffer_dirty(bh)) { /* This should probably be a BUG, or * at least return an error. */ continue; } /* A read-ahead request was made - if the * buffer is already under read-ahead from a * previously submitted request than we are * done here. */ if ((flags & OCFS2_BH_READAHEAD) && ocfs2_buffer_read_ahead(ci, bh)) continue; lock_buffer(bh); if (buffer_jbd(bh)) { #ifdef CATCH_BH_JBD_RACES mlog(ML_ERROR, "block %llu had the JBD bit set " "while I was in lock_buffer!", (unsigned long long)bh->b_blocknr); BUG(); #else unlock_buffer(bh); continue; #endif } /* Re-check ocfs2_buffer_uptodate() as a * previously read-ahead buffer may have * completed I/O while we were waiting for the * buffer lock. */ if (!(flags & OCFS2_BH_IGNORE_CACHE) && !(flags & OCFS2_BH_READAHEAD) && ocfs2_buffer_uptodate(ci, bh)) { unlock_buffer(bh); continue; } clear_buffer_uptodate(bh); get_bh(bh); /* for end_buffer_read_sync() */ if (validate) set_buffer_needs_validate(bh); bh->b_end_io = end_buffer_read_sync; submit_bh(REQ_OP_READ, 0, bh); continue; } } status = 0; for (i = (nr - 1); i >= 0; i--) { bh = bhs[i]; if (!(flags & OCFS2_BH_READAHEAD)) { if (status) { /* Clear the rest of the buffers on error */ put_bh(bh); bhs[i] = NULL; continue; } /* We know this can't have changed as we hold the * owner sem. Avoid doing any work on the bh if the * journal has it. */ if (!buffer_jbd(bh)) wait_on_buffer(bh); if (!buffer_uptodate(bh)) { /* Status won't be cleared from here on out, * so we can safely record this and loop back * to cleanup the other buffers. Don't need to * remove the clustered uptodate information * for this bh as it's not marked locally * uptodate. */ status = -EIO; put_bh(bh); bhs[i] = NULL; continue; } if (buffer_needs_validate(bh)) { /* We never set NeedsValidate if the * buffer was held by the journal, so * that better not have changed */ BUG_ON(buffer_jbd(bh)); clear_buffer_needs_validate(bh); status = validate(sb, bh); if (status) { put_bh(bh); bhs[i] = NULL; continue; } } } /* Always set the buffer in the cache, even if it was * a forced read, or read-ahead which hasn't yet * completed. */ ocfs2_set_buffer_uptodate(ci, bh); } ocfs2_metadata_cache_io_unlock(ci); trace_ocfs2_read_blocks_end((unsigned long long)block, nr, flags, ignore_cache); bail: return status; }

Contributors

PersonTokensPropCommitsCommitProp
mark fashehmark fasheh50574.81%430.77%
joel beckerjoel becker12117.93%430.77%
tao matao ma253.70%215.38%
goldwyn rodriguesgoldwyn rodrigues202.96%17.69%
michael christiemichael christie30.44%17.69%
rui xiangrui xiang10.15%17.69%
Total675100.00%13100.00%

/* Check whether the blkno is the super block or one of the backups. */
static void ocfs2_check_super_or_backup(struct super_block *sb, sector_t blkno) { int i; u64 backup_blkno; if (blkno == OCFS2_SUPER_BLOCK_BLKNO) return; for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) { backup_blkno = ocfs2_backup_super_blkno(sb, i); if (backup_blkno == blkno) return; } BUG(); }

Contributors

PersonTokensPropCommitsCommitProp
tao matao ma61100.00%1100.00%
Total61100.00%1100.00%

/* * Write super block and backups doesn't need to collaborate with journal, * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed * into this function. */
int ocfs2_write_super_or_backup(struct ocfs2_super *osb, struct buffer_head *bh) { int ret = 0; struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data; BUG_ON(buffer_jbd(bh)); ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr); if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) { ret = -EROFS; mlog_errno(ret); goto out; } lock_buffer(bh); set_buffer_uptodate(bh); /* remove from dirty list before I/O. */ clear_buffer_dirty(bh); get_bh(bh); /* for end_buffer_write_sync() */ bh->b_end_io = end_buffer_write_sync; ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check); submit_bh(REQ_OP_WRITE, 0, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { ret = -EIO; mlog_errno(ret); } out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
tao matao ma13079.75%250.00%
joel beckerjoel becker3018.40%125.00%
michael christiemichael christie31.84%125.00%
Total163100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
mark fashehmark fasheh68447.30%628.57%
joel beckerjoel becker46832.37%628.57%
tao matao ma24416.87%419.05%
goldwyn rodriguesgoldwyn rodrigues201.38%14.76%
gang hegang he130.90%14.76%
michael christiemichael christie120.83%14.76%
christoph hellwigchristoph hellwig30.21%14.76%
rui xiangrui xiang20.14%14.76%
Total1446100.00%21100.00%
Directory: fs/ocfs2
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