Upstream-Status: inappropriate

From fd1f52c435099eab199f2b06eb411aab337d7f47 Mon Sep 17 00:00:00 2001
From: Corey Minyard <cminyard@mvista.com>
Date: Tue, 7 Jun 2011 07:29:53 -0500
Subject: [PATCH 18/19] Handle files changing while we are working

Files may change or be deleted between the lstat and the actual
operation to read them and put them into the target filesystem.
Handle this more gracefully.  Warn on file deletions, and handle
whatever size is read, not whatever size happens to be in the
inode when we stat-ed it.

Also clear the data to the end of an file's last block, to keep
things clean.
---
 genext2fs.c |   30 ++++++++++++++++++------------
 1 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/genext2fs.c b/genext2fs.c
index 485393c..28ba94f 100644
--- a/genext2fs.c
+++ b/genext2fs.c
@@ -1942,19 +1942,30 @@ fs_upgrade_rev1_largefile(filesystem *fs)
 
 // make a file from a FILE*
 static uint32
-mkfile_fs(filesystem *fs, uint32 parent_nod, const char *name, uint32 mode, off_t size, FILE *f, uid_t uid, gid_t gid, uint32 ctime, uint32 mtime)
+mkfile_fs(filesystem *fs, uint32 parent_nod, const char *name, uint32 mode, FILE *f, uid_t uid, gid_t gid, uint32 ctime, uint32 mtime)
 {
 	uint8 * b;
 	uint32 nod = mknod_fs(fs, parent_nod, name, mode|FM_IFREG, uid, gid, 0, 0, ctime, mtime);
 	nod_info *ni;
 	inode *node = get_nod(fs, nod, &ni);
+	off_t size = 0;
 	size_t readbytes;
 	inode_pos ipos;
+	int fullsize;
 
 	b = malloc(CB_SIZE);
 	if (!b)
 		error_msg_and_die("mkfile_fs: out of memory");
 	inode_pos_init(fs, &ipos, nod, INODE_POS_TRUNCATE, NULL);
+	readbytes = fread(b, 1, CB_SIZE, f);
+	while (readbytes) {
+		fullsize = rndup(readbytes, BLOCKSIZE);
+		// Fill to end of block with zeros.
+		memset(b + readbytes, 0, fullsize - readbytes);
+		extend_inode_blk(fs, &ipos, b, fullsize / BLOCKSIZE);
+		size += readbytes;
+		readbytes = fread(b, 1, CB_SIZE, f);
+	}
 	if (size > 0x7fffffff) {
 		if (fs->sb->s_rev_level < 1)
 			fs_upgrade_rev1_largefile(fs);
@@ -1962,15 +1973,6 @@ mkfile_fs(filesystem *fs, uint32 parent_nod, const char *name, uint32 mode, off_
 	}
 	node->i_dir_acl = size >> 32;
 	node->i_size = size;
-	while (size) {
-		readbytes = fread(b, 1, CB_SIZE, f);
-		if ((size < CB_SIZE && readbytes != size)
-		    || (size >= CB_SIZE && readbytes != CB_SIZE))
-			error_msg_and_die("fread failed");
-		extend_inode_blk(fs, &ipos, b,
-				 rndup(readbytes, BLOCKSIZE) / BLOCKSIZE);
-		size -= readbytes;
-	}
 	inode_pos_finish(fs, &ipos);
 	put_nod(ni);
 	free(b);
@@ -2256,8 +2258,12 @@ add2fs_from_dir(filesystem *fs, uint32 this_nod, int squash_uids, int squash_per
 					free(lnk);
 					break;
 				case S_IFREG:
-					fh = xfopen(dent->d_name, "rb");
-					nod = mkfile_fs(fs, this_nod, name, mode, st.st_size, fh, uid, gid, ctime, mtime);
+					fh = fopen(dent->d_name, "rb");
+					if (!fh) {
+						error_msg("Unable to open file %s", dent->d_name);
+						break;
+					}
+					nod = mkfile_fs(fs, this_nod, name, mode, fh, uid, gid, ctime, mtime);
 					fclose(fh);
 					break;
 				case S_IFDIR:
-- 
1.7.4.1