ext4: fix fsx truncate failure

While running extended fsx tests to verify the first
two patches, a similar bug was also found in the
truncate operation.

This bug happens because the truncate routine only zeros
the unblock aligned portion of the last page.  This means
that the block aligned portions of the page appearing after
i_size are left unzeroed, and the buffer heads still mapped.

This bug is corrected by using ext4_discard_partial_page_buffers
in the truncate routine to zero the partial page and unmap
the buffer headers.

Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 2c5216a8d03be84c808243c55dea8c04b86b64dc..ba7bd5a176ce79fa45239050e32b2cd58f19577b 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3653,6 +3653,7 @@ void ext4_ext_truncate(struct inode *inode)
        struct super_block *sb = inode->i_sb;
        ext4_lblk_t last_block;
        handle_t *handle;
+       loff_t page_len;
        int err = 0;
 
        /*
@@ -3669,8 +3670,16 @@ void ext4_ext_truncate(struct inode *inode)
        if (IS_ERR(handle))
                return;
 
-       if (inode->i_size & (sb->s_blocksize - 1))
-               ext4_block_truncate_page(handle, mapping, inode->i_size);
+       if (inode->i_size % PAGE_CACHE_SIZE != 0) {
+               page_len = PAGE_CACHE_SIZE -
+                       (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+               err = ext4_discard_partial_page_buffers(handle,
+                       mapping, inode->i_size, page_len, 0);
+
+               if (err)
+                       goto out_stop;
+       }
 
        if (ext4_orphan_add(handle, inode))
                goto out_stop;

diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index 0962642119c0475953fc70da38a5ed9bbea417a2..ea704dff866987655ee8a41ab88c260fcd634b86 100644 (file)
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1343,7 +1343,9 @@ void ext4_ind_truncate(struct inode *inode)
        __le32 nr = 0;
        int n = 0;
        ext4_lblk_t last_block, max_block;
+       loff_t page_len;
        unsigned blocksize = inode->i_sb->s_blocksize;
+       int err;
 
        handle = start_transaction(inode);
        if (IS_ERR(handle))
@@ -1354,9 +1356,16 @@ void ext4_ind_truncate(struct inode *inode)
        max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
                                        >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
 
-       if (inode->i_size & (blocksize - 1))
-               if (ext4_block_truncate_page(handle, mapping, inode->i_size))
+       if (inode->i_size % PAGE_CACHE_SIZE != 0) {
+               page_len = PAGE_CACHE_SIZE -
+                       (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+               err = ext4_discard_partial_page_buffers(handle,
+                       mapping, inode->i_size, page_len, 0);
+
+               if (err)
                        goto out_stop;
+       }
 
        if (last_block != max_block) {
                n = ext4_block_to_path(inode, last_block, offsets, NULL);