From: Joel Becker Date: Thu, 13 Nov 2008 22:49:17 +0000 (-0800) Subject: ocfs2: Wrap dirblock reads in a dedicated function. X-Git-Tag: v2.6.29-rc1~505^2~100 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=a22305cc693254a2aa651e797875669112ef8635;p=linux-2.6-omap-h63xx.git ocfs2: Wrap dirblock reads in a dedicated function. We have ocfs2_bread() as a vestige of the original ext-based dir code. It's only used by directories, though. Turn it into ocfs2_read_dir_block(), with a prototype matching the other metadata read functions. It's set up to validate dirblocks when the time comes. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 5777045f1a6..c2f3fd93be5 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -82,49 +82,6 @@ static int ocfs2_do_extend_dir(struct super_block *sb, struct ocfs2_alloc_context *meta_ac, struct buffer_head **new_bh); -static struct buffer_head *ocfs2_bread(struct inode *inode, - int block, int *err, int reada) -{ - struct buffer_head *bh = NULL; - int tmperr; - u64 p_blkno; - int readflags = 0; - - if (reada) - readflags |= OCFS2_BH_READAHEAD; - - if (((u64)block << inode->i_sb->s_blocksize_bits) >= - i_size_read(inode)) { - BUG_ON(!reada); - return NULL; - } - - down_read(&OCFS2_I(inode)->ip_alloc_sem); - tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, - NULL); - up_read(&OCFS2_I(inode)->ip_alloc_sem); - if (tmperr < 0) { - mlog_errno(tmperr); - goto fail; - } - - tmperr = ocfs2_read_blocks(inode, p_blkno, 1, &bh, readflags); - if (tmperr < 0) - goto fail; - - tmperr = 0; - - *err = 0; - return bh; - -fail: - brelse(bh); - bh = NULL; - - *err = -EIO; - return NULL; -} - /* * bh passed here can be an inode block or a dir data block, depending * on the inode inline data flag. @@ -250,6 +207,76 @@ out: return NULL; } +static int ocfs2_validate_dir_block(struct super_block *sb, + struct buffer_head *bh) +{ + /* + * Nothing yet. We don't validate dirents here, that's handled + * in-place when the code walks them. + */ + + return 0; +} + +/* + * This function forces all errors to -EIO for consistency with its + * predecessor, ocfs2_bread(). We haven't audited what returning the + * real error codes would do to callers. We log the real codes with + * mlog_errno() before we squash them. + */ +static int ocfs2_read_dir_block(struct inode *inode, u64 v_block, + struct buffer_head **bh, int flags) +{ + int rc = 0; + struct buffer_head *tmp = *bh; + u64 p_blkno; + + if (((u64)v_block << inode->i_sb->s_blocksize_bits) >= + i_size_read(inode)) { + BUG_ON(!(flags & OCFS2_BH_READAHEAD)); + goto out; + } + + down_read(&OCFS2_I(inode)->ip_alloc_sem); + rc = ocfs2_extent_map_get_blocks(inode, v_block, &p_blkno, NULL, + NULL); + up_read(&OCFS2_I(inode)->ip_alloc_sem); + if (rc) { + mlog_errno(rc); + goto out; + } + + if (!p_blkno) { + rc = -EIO; + mlog(ML_ERROR, + "Directory #%llu contains a hole at offset %llu\n", + (unsigned long long)OCFS2_I(inode)->ip_blkno, + (unsigned long long)v_block << inode->i_sb->s_blocksize_bits); + goto out; + } + + rc = ocfs2_read_blocks(inode, p_blkno, 1, &tmp, flags); + if (rc) { + mlog_errno(rc); + goto out; + } + + if (!(flags & OCFS2_BH_READAHEAD)) { + rc = ocfs2_validate_dir_block(inode->i_sb, tmp); + if (rc) { + brelse(tmp); + goto out; + } + } + + /* If ocfs2_read_blocks() got us a new bh, pass it up. */ + if (!*bh) + *bh = tmp; + +out: + return rc ? -EIO : 0; +} + static struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen, struct inode *dir, struct ocfs2_dir_entry **res_dir) @@ -296,15 +323,17 @@ restart: } num++; - bh = ocfs2_bread(dir, b++, &err, 1); + bh = NULL; + err = ocfs2_read_dir_block(dir, b++, &bh, + OCFS2_BH_READAHEAD); bh_use[ra_max] = bh; } } if ((bh = bh_use[ra_ptr++]) == NULL) goto next; - if (ocfs2_read_block(dir, block, &bh)) { + if (ocfs2_read_dir_block(dir, block, &bh, 0)) { /* read error, skip block & hope for the best. - * ocfs2_read_block() has released the bh. */ + * ocfs2_read_dir_block() has released the bh. */ ocfs2_error(dir->i_sb, "reading directory %llu, " "offset %lu\n", (unsigned long long)OCFS2_I(dir)->ip_blkno, @@ -724,7 +753,6 @@ static int ocfs2_dir_foreach_blk_el(struct inode *inode, int i, stored; struct buffer_head * bh, * tmp; struct ocfs2_dir_entry * de; - int err; struct super_block * sb = inode->i_sb; unsigned int ra_sectors = 16; @@ -735,12 +763,8 @@ static int ocfs2_dir_foreach_blk_el(struct inode *inode, while (!error && !stored && *f_pos < i_size_read(inode)) { blk = (*f_pos) >> sb->s_blocksize_bits; - bh = ocfs2_bread(inode, blk, &err, 0); - if (!bh) { - mlog(ML_ERROR, - "directory #%llu contains a hole at offset %lld\n", - (unsigned long long)OCFS2_I(inode)->ip_blkno, - *f_pos); + if (ocfs2_read_dir_block(inode, blk, &bh, 0)) { + /* Skip the corrupt dirblock and keep trying */ *f_pos += sb->s_blocksize - offset; continue; } @@ -754,8 +778,10 @@ static int ocfs2_dir_foreach_blk_el(struct inode *inode, || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) { for (i = ra_sectors >> (sb->s_blocksize_bits - 9); i > 0; i--) { - tmp = ocfs2_bread(inode, ++blk, &err, 1); - brelse(tmp); + tmp = NULL; + if (!ocfs2_read_dir_block(inode, ++blk, &tmp, + OCFS2_BH_READAHEAD)) + brelse(tmp); } last_ra_blk = blk; ra_sectors = 8; @@ -828,6 +854,7 @@ revalidate: } offset = 0; brelse(bh); + bh = NULL; } stored = 0; @@ -1680,8 +1707,8 @@ static int ocfs2_find_dir_space_el(struct inode *dir, const char *name, struct super_block *sb = dir->i_sb; int status; - bh = ocfs2_bread(dir, 0, &status, 0); - if (!bh) { + status = ocfs2_read_dir_block(dir, 0, &bh, 0); + if (status) { mlog_errno(status); goto bail; } @@ -1702,11 +1729,10 @@ static int ocfs2_find_dir_space_el(struct inode *dir, const char *name, status = -ENOSPC; goto bail; } - bh = ocfs2_bread(dir, - offset >> sb->s_blocksize_bits, - &status, - 0); - if (!bh) { + status = ocfs2_read_dir_block(dir, + offset >> sb->s_blocksize_bits, + &bh, 0); + if (status) { mlog_errno(status); goto bail; }