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authorEric Sandeen <sandeen@redhat.com>2008-01-28 23:58:27 -0500
committerTheodore Ts'o <tytso@mit.edu>2008-01-28 23:58:27 -0500
commite2b4657453c0d5571bd3c7256585c486ed42d364 (patch)
tree5b8ab501cdf5fa7427ef32440ace56eac72e9ecf /fs/ext4/file.c
parent19295529db35381d46dbaf246f69b4e3b3393996 (diff)
downloadlinux-e2b4657453c0d5571bd3c7256585c486ed42d364.tar.gz
ext4: store maxbytes for bitmapped files and return EFBIG as appropriate
Calculate & store the max offset for bitmapped files, and
catch too-large seeks, truncates, and writes in ext4, shortening
or rejecting as appropriate.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Diffstat (limited to 'fs/ext4/file.c')
-rw-r--r--fs/ext4/file.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1a81cd66d63b..a6b2aa14626e 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -56,8 +56,25 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
 	ssize_t ret;
 	int err;
 
-	ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+	/*
+	 * If we have encountered a bitmap-format file, the size limit
+	 * is smaller than s_maxbytes, which is for extent-mapped files.
+	 */
+
+	if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+		size_t length = iov_length(iov, nr_segs);
 
+		if (pos > sbi->s_bitmap_maxbytes)
+			return -EFBIG;
+
+		if (pos + length > sbi->s_bitmap_maxbytes) {
+			nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+					      sbi->s_bitmap_maxbytes - pos);
+		}
+	}
+
+	ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
 	/*
 	 * Skip flushing if there was an error, or if nothing was written.
 	 */