misc/create_inode.c: copy regular file

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 <liezhi.yang@windriver.com>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/misc/create_inode.c b/misc/create_inode.c
index f845103..98f4a93 100644 (file)
--- 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;
+       }
+#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;
+               }
+               retval = ext2fs_link(current_fs, cwd, dest, newfile,
+                                       EXT2_FT_REG_FILE);
+       }
+       if (retval) {
+               com_err(dest, retval, 0);
+               close(fd);
+               return errno;
+       }
+        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 */