land b1_5 onto HEAD

[fs/lustre-release.git] / lustre / kernel_patches / patches / ext3-truncate_blocks.patch

diff --git a/lustre/kernel_patches/patches/ext3-truncate_blocks.patch b/lustre/kernel_patches/patches/ext3-truncate_blocks.patch
new file mode 100644 (file)
index 0000000..ce3928d
--- /dev/null
+++ b/lustre/kernel_patches/patches/ext3-truncate_blocks.patch
@@ -0,0 +1,92 @@
+--- ./fs/ext3/inode.c.orig     Wed Mar 12 02:44:06 2003
++++ ./fs/ext3/inode.c  Wed Mar 12 11:55:20 2003
+@@ -99,7 +99,35 @@ int ext3_forget(handle_t *handle, int is
+       return err;
+ }
+ 
+-/* 
++/*
++ * Work out how many blocks we need to progress with the next chunk of a
++ * truncate transaction.
++ */
++
++static unsigned long blocks_for_truncate(struct inode *inode)
++{
++      unsigned long needed;
++
++      needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
++
++      /* Give ourselves just enough room to cope with inodes in which
++       * i_blocks is corrupt: we've seen disk corruptions in the past
++       * which resulted in random data in an inode which looked enough
++       * like a regular file for ext3 to try to delete it.  Things
++       * will go a bit crazy if that happens, but at least we should
++       * try not to panic the whole kernel. */
++      if (needed < 2)
++              needed = 2;
++
++      /* But we need to bound the transaction so we don't overflow the
++       * journal. */
++      if (needed > EXT3_MAX_TRANS_DATA)
++              needed = EXT3_MAX_TRANS_DATA;
++
++      return EXT3_DATA_TRANS_BLOCKS + needed;
++}
++
++/*
+  * Truncate transactions can be complex and absolutely huge.  So we need to
+  * be able to restart the transaction at a conventient checkpoint to make
+  * sure we don't overflow the journal.
+@@ -110,19 +138,14 @@ int ext3_forget(handle_t *handle, int is
+  * transaction in the top-level truncate loop. --sct 
+  */
+ 
+-static handle_t *start_transaction(struct inode *inode) 
++static handle_t *start_transaction(struct inode *inode)
+ {
+-      long needed;
+       handle_t *result;
+-      
+-      needed = inode->i_blocks;
+-      if (needed > EXT3_MAX_TRANS_DATA) 
+-              needed = EXT3_MAX_TRANS_DATA;
+-      
+-      result = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS + needed);
++
++      result = ext3_journal_start(inode, blocks_for_truncate(inode));
+       if (!IS_ERR(result))
+               return result;
+-      
++
+       ext3_std_error(inode->i_sb, PTR_ERR(result));
+       return result;
+ }
+@@ -135,14 +158,9 @@ static handle_t *start_transaction(struc
+  */
+ static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
+ {
+-      long needed;
+-      
+       if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
+               return 0;
+-      needed = inode->i_blocks;
+-      if (needed > EXT3_MAX_TRANS_DATA) 
+-              needed = EXT3_MAX_TRANS_DATA;
+-      if (!ext3_journal_extend(handle, EXT3_RESERVE_TRANS_BLOCKS + needed))
++      if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
+               return 0;
+       return 1;
+ }
+@@ -154,11 +172,8 @@ static int try_to_extend_transaction(han
+  */
+ static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
+ {
+-      long needed = inode->i_blocks;
+-      if (needed > EXT3_MAX_TRANS_DATA) 
+-              needed = EXT3_MAX_TRANS_DATA;
+       jbd_debug(2, "restarting handle %p\n", handle);
+-      return ext3_journal_restart(handle, EXT3_DATA_TRANS_BLOCKS + needed);
++      return ext3_journal_restart(handle, blocks_for_truncate(inode));
+ }
+ 
+ /*