From: "Darrick J. Wong" Subject: Re: [PATCH V4 05/11] misc/create_inode.c: copy regular file Date: Thu, 6 Mar 2014 11:06:22 -0800 Message-ID: <20140306190622.GE9875@birch.djwong.org> References: <1393661175-459-1-git-send-email-liezhi.yang@windriver.com> <1393661175-459-6-git-send-email-liezhi.yang@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: tytso@mit.edu, dvhart@linux.intel.com, linux-ext4@vger.kernel.org To: Robert Yang Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:50934 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752793AbaCFTG3 (ORCPT ); Thu, 6 Mar 2014 14:06:29 -0500 Content-Disposition: inline In-Reply-To: <1393661175-459-6-git-send-email-liezhi.yang@windriver.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: I noticed a few things while merging -next into my dev tree... On Sat, Mar 01, 2014 at 03:06:09AM -0500, Robert Yang wrote: > The do_write_internal() is used for copying file from native fs to > target, most of the code are from debugfs/debugfs.c, the > debugfs/debugfs.c will be modified to use this function. > > Signed-off-by: Robert Yang > Reviewed-by: Darren Hart > --- > misc/create_inode.c | 183 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 183 insertions(+) > > diff --git a/misc/create_inode.c b/misc/create_inode.c > index f845103..98f4a93 100644 > --- a/misc/create_inode.c > +++ b/misc/create_inode.c > @@ -8,6 +8,16 @@ > # endif > #endif > > +/* 64KiB is the minimium blksize to best minimize system call overhead. */ > +#ifndef IO_BUFSIZE > +#define IO_BUFSIZE 64*1024 > +#endif > + > +/* Block size for `st_blocks' */ > +#ifndef S_BLKSIZE > +#define S_BLKSIZE 512 > +#endif > + > /* Make a special file which is block, character and fifo */ > errcode_t do_mknod_internal(ext2_ino_t cwd, const char *name, struct stat *st) > { > @@ -127,9 +137,182 @@ errcode_t do_mkdir_internal(ext2_ino_t cwd, const char *name, struct stat *st) > { > } > > +static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_holes) > +{ > + ext2_file_t e2_file; > + errcode_t retval; > + int got; > + unsigned int written; > + char *buf; > + char *ptr; > + char *zero_buf; > + int cmp; > + > + retval = ext2fs_file_open(current_fs, newfile, > + EXT2_FILE_WRITE, &e2_file); > + if (retval) > + return retval; > + > + retval = ext2fs_get_mem(bufsize, &buf); > + if (retval) { > + com_err("copy_file", retval, "can't allocate buffer\n"); > + return retval; > + } > + > + /* This is used for checking whether the whole block is zero */ > + retval = ext2fs_get_memzero(bufsize, &zero_buf); > + if (retval) { > + com_err("copy_file", retval, "can't allocate buffer\n"); > + ext2fs_free_mem(&buf); > + return retval; > + } > + > + while (1) { > + got = read(fd, buf, bufsize); > + if (got == 0) > + break; > + if (got < 0) { > + retval = errno; > + goto fail; > + } > + ptr = buf; > + > + /* Sparse copy */ > + if (make_holes) { > + /* Check whether all is zero */ > + cmp = memcmp(ptr, zero_buf, got); > + if (cmp == 0) { > + /* The whole block is zero, make a hole */ > + retval = ext2fs_file_lseek(e2_file, got, EXT2_SEEK_CUR, NULL); > + if (retval) > + goto fail; > + got = 0; > + } > + } > + > + /* Normal copy */ > + while (got > 0) { > + retval = ext2fs_file_write(e2_file, ptr, > + got, &written); > + if (retval) > + goto fail; > + > + got -= written; > + ptr += written; > + } > + } > + ext2fs_free_mem(&buf); > + ext2fs_free_mem(&zero_buf); > + retval = ext2fs_file_close(e2_file); > + return retval; > + > +fail: > + ext2fs_free_mem(&buf); > + ext2fs_free_mem(&zero_buf); > + (void) ext2fs_file_close(e2_file); > + return retval; > +} > + > /* Copy the native file to the fs */ > errcode_t do_write_internal(ext2_ino_t cwd, const char *src, const char *dest) > { > + int fd; > + struct stat statbuf; > + ext2_ino_t newfile; > + errcode_t retval; > + struct ext2_inode inode; > + int bufsize = IO_BUFSIZE; > + int make_holes = 0; > + > + fd = open(src, O_RDONLY); > + if (fd < 0) { > + com_err(src, errno, 0); > + return errno; > + } > + if (fstat(fd, &statbuf) < 0) { > + com_err(src, errno, 0); > + close(fd); > + return errno; > + } > + > + retval = ext2fs_namei(current_fs, root, cwd, dest, &newfile); > + if (retval == 0) { > + com_err(__func__, 0, "The file '%s' already exists\n", dest); > + close(fd); > + return errno; > + } > + > + retval = ext2fs_new_inode(current_fs, cwd, 010755, 0, &newfile); > + if (retval) { > + com_err(__func__, retval, 0); > + close(fd); > + return errno; Why return errno here, instead of retval? > + } > +#ifdef DEBUGFS > + printf("Allocated inode: %u\n", newfile); > +#endif > + retval = ext2fs_link(current_fs, cwd, dest, newfile, > + EXT2_FT_REG_FILE); > + if (retval == EXT2_ET_DIR_NO_SPACE) { > + retval = ext2fs_expand_dir(current_fs, cwd); > + if (retval) { > + com_err(__func__, retval, "while expanding directory"); > + close(fd); > + return errno; Or here... > + } > + retval = ext2fs_link(current_fs, cwd, dest, newfile, > + EXT2_FT_REG_FILE); > + } > + if (retval) { > + com_err(dest, retval, 0); > + close(fd); > + return errno; Or here... --D > + } > + if (ext2fs_test_inode_bitmap2(current_fs->inode_map, newfile)) > + com_err(__func__, 0, "Warning: inode already set"); > + ext2fs_inode_alloc_stats2(current_fs, newfile, +1, 0); > + memset(&inode, 0, sizeof(inode)); > + inode.i_mode = (statbuf.st_mode & ~LINUX_S_IFMT) | LINUX_S_IFREG; > + inode.i_atime = inode.i_ctime = inode.i_mtime = > + current_fs->now ? current_fs->now : time(0); > + inode.i_links_count = 1; > + inode.i_size = statbuf.st_size; > + if (current_fs->super->s_feature_incompat & > + EXT3_FEATURE_INCOMPAT_EXTENTS) { > + int i; > + struct ext3_extent_header *eh; > + > + eh = (struct ext3_extent_header *) &inode.i_block[0]; > + eh->eh_depth = 0; > + eh->eh_entries = 0; > + eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC); > + i = (sizeof(inode.i_block) - sizeof(*eh)) / > + sizeof(struct ext3_extent); > + eh->eh_max = ext2fs_cpu_to_le16(i); > + inode.i_flags |= EXT4_EXTENTS_FL; > + } > + > + if ((retval = ext2fs_write_new_inode(current_fs, newfile, &inode))) { > + com_err(__func__, retval, "while creating inode %u", newfile); > + close(fd); > + return errno; > + } > + if (LINUX_S_ISREG(inode.i_mode)) { > + if (statbuf.st_blocks < statbuf.st_size / S_BLKSIZE) { > + make_holes = 1; > + /* > + * Use I/O blocksize as buffer size when > + * copying sparse files. > + */ > + bufsize = statbuf.st_blksize; > + } > + retval = copy_file(fd, newfile, bufsize, make_holes); > + if (retval) > + com_err("copy_file", retval, 0); > + } > + close(fd); > + > + return 0; > } > > /* Copy files from source_dir to fs */ > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html