ext4: Split uninitialized extents for direct I/O
When writing into an unitialized extent via direct I/O, and the direct
I/O doesn't exactly cover the unitialized extent, split the extent
into uninitialized and initialized extents before submitting the I/O.
This avoids needing to deal with an ENOSPC error in the end_io
callback that gets used for direct I/O.
When the IO is complete, the written extent will be marked as initialized.
Singed-Off-By: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 219067c..da4f2ec 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1233,6 +1233,9 @@
clear_buffer_mapped(bh);
clear_buffer_unwritten(bh);
+ ext_debug("ext4_get_blocks(): inode %lu, flag %d, max_blocks %u,"
+ "logical block %lu\n", inode->i_ino, flags, max_blocks,
+ (unsigned long)block);
/*
* Try to see if we can get the block without requesting a new
* file system block.