[lkml]   [2003]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] [2.4] beyond_eof check in generic_direct_IO
Hello all,

reiserfs has to do a few odd tail conversion steps during direct io.
Picture a file whose size is currently 3500 bytes, and a direct io write
extending it to 4096 bytes.

reiserfs will have those 3500 bytes packed into a tail, and when it gets
a get_block call with create == 1, it will convert the tail into a full
block and return the newly created block.

The new generic_direct_IO code doesn't send create == 1 to get_block
unless the new block is entirely past eof. I think it should instead
allow any part of the block to be past eof, which allows reiserfs to
properly convert the tail:


--- 1.89/fs/buffer.c Tue Jun 24 17:11:29 2003
+++ edited/fs/buffer.c Fri Jul 18 13:24:57 2003
@@ -2147,7 +2148,7 @@
bh.b_size = blocksize;
bh.b_page = NULL;

- if (((loff_t) blocknr) * blocksize >= inode->i_size)
+ if (((loff_t) (blocknr + 1)) * blocksize > inode->i_size)
beyond_eof = 1;

/* Only allow get_block to create new blocks if we are safely

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:47    [W:0.024 / U:7.896 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site