From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Thu, 12 Dec 2013 18:19:46 +0000 (-0500)
Subject: libext2fs: fail fileio write if we can't allocate a block
X-Git-Tag: v1.42.9~65
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=8a86bbb19714c135aef07095d0b3c1d7e4f7a155;p=tools%2Fe2fsprogs.git

libext2fs: fail fileio write if we can't allocate a block

If we're using ext2fs_file_write() to write to a hole in a file,
ensure that we can actually allocate the block before updating i_size.
In other words, don't update i_size and don't return success if we hit
an error while allocating space.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c
index d092e65..03bdf86 100644
--- a/lib/ext2fs/fileio.c
+++ b/lib/ext2fs/fileio.c
@@ -297,6 +297,20 @@ errcode_t ext2fs_file_write(ext2_file_t file, const void *buf,
 		if (retval)
 			goto fail;
 
+		/*
+		 * OK, the physical block hasn't been allocated yet.
+		 * Allocate it.
+		 */
+		if (!file->physblock) {
+			retval = ext2fs_bmap2(fs, file->ino, &file->inode,
+					      BMAP_BUFFER,
+					      file->ino ? BMAP_ALLOC : 0,
+					      file->blockno, 0,
+					      &file->physblock);
+			if (retval)
+				goto fail;
+		}
+
 		file->flags |= EXT2_FILE_BUF_DIRTY;
 		memcpy(file->buf+start, ptr, c);
 		file->pos += c;