From: Mingming Date: Tue, 10 Nov 2009 15:48:08 +0000 (-0500) Subject: ext4: fix ext4_ext_direct_IO()'s return value after converting uninit extents X-Git-Tag: v2.6.31.8~38 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e270fa58d81a994d1e4371be444f2e5bb072866;p=thirdparty%2Fkernel%2Fstable.git ext4: fix ext4_ext_direct_IO()'s return value after converting uninit extents (cherry picked from commit 109f55651954def97fa41ee71c464d268c512ab0) After a direct I/O request covering an uninitalized extent (i.e., created using the fallocate system call) or a hole in a file, ext4 will convert the uninitialized extent so it is marked as initialized by calling ext4_convert_unwritten_extents(). This function returns zero on success. This return value was getting returned by ext4_direct_IO(); however the file system's direct_IO function is supposed to return the number of bytes read or written on a success. By returning zero, it confused the direct I/O code into falling back to buffered I/O unnecessarily. Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index aee15f1c47817..07839434bdb13 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3496,6 +3496,7 @@ retry: * * This function is called from the direct IO end io call back * function, to convert the fallocated extents after IO is completed. + * Returns 0 on success. */ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, loff_t len) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 02e51961e71a7..88e47124e8ba7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3766,13 +3766,17 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) { ext4_free_io_end(iocb->private); iocb->private = NULL; - } else if (ret > 0) + } else if (ret > 0) { + int err; /* * for non AIO case, since the IO is already * completed, we could do the convertion right here */ - ret = ext4_convert_unwritten_extents(inode, - offset, ret); + err = ext4_convert_unwritten_extents(inode, + offset, ret); + if (err < 0) + ret = err; + } return ret; }