Hi,
We can create 4402345721856 byte file with indirect block mapping.
However, if we grow an indirect-block file to the size with ftruncate(),
we can see the ext4 warning. The following patch fixes this problem.
How to reproduce:
# dd if=/dev/zero of=/mnt/mp1/hoge bs=1 count=0 seek=4402345721856
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000221428 s, 0.0 kB/s
# tail -n 1 /var/log/messages
Nov 25 15:10:27 test kernel: EXT4-fs warning (device sda8): ext4_block_to_path:345: block 1074791436 > max in inode 12
Signed-off-by: Kazuya Mio <k-mio@xxxxxxxxxxxxx>
---
fs/ext4/inode.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 05a0790..c429753 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4677,8 +4677,8 @@ void ext4_truncate(struct inode *inode)
Indirect chain[4];
Indirect *partial;
__le32 nr = 0;
- int n;
- ext4_lblk_t last_block;
+ int n = 0;
+ ext4_lblk_t last_block, max_block;
unsigned blocksize = inode->i_sb->s_blocksize;
if (!ext4_can_truncate(inode))
@@ -4700,14 +4700,18 @@ void ext4_truncate(struct inode *inode)
last_block = (inode->i_size + blocksize-1)
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+ 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))
goto out_stop;
- n = ext4_block_to_path(inode, last_block, offsets, NULL);
- if (n == 0)
- goto out_stop; /* error */
+ if (last_block != max_block) {
+ n = ext4_block_to_path(inode, last_block, offsets, NULL);
+ if (n == 0)
+ goto out_stop; /* error */
+ }
/*
* OK. This truncate is going to happen. We add the inode to the
@@ -4738,7 +4742,13 @@ void ext4_truncate(struct inode *inode)
*/
ei->i_disksize = inode->i_size;
- if (n == 1) { /* direct blocks */
+ if (last_block == max_block) {
+ /*
+ * It is unnecessary to free any data blocks if last_block is
+ * equal to the indirect block limit.
+ */
+ goto out_unlock;
+ } else if (n == 1) { /* direct blocks */
ext4_free_data(handle, inode, NULL, i_data+offsets[0],
i_data + EXT4_NDIR_BLOCKS);
goto do_indirects;
@@ -4798,6 +4808,7 @@ do_indirects:
;
}
+out_unlock:
up_write(&ei->i_data_sem);
inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
--
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