On Mon, 2007-07-16 at 18:06 -0600, Andreas Dilger wrote:
> On Jul 16, 2007 16:52 -0700, Mingming Cao wrote:
> > I am not sure why we need GFP_KERNEL flag here. I think we should use
> > GFP_NOFS instead. The following patch use the GFP_NOFS flag, as well as
> > fixing memory leak issue introduced by the ext4 expand inode extra isize
> > patch.
> >
> > Fixing memory allocation issue with expand inode extra isize patch.
> >
> > - use GFP_NOFS instead of GFP_KERNEL flag for memory allocation
> > - use kzalloc instead of kmalloc
>
> This doesn't need kzalloc() for buffer and b_entry_name, since they are
> immediately overwritten by memcpy().
>
ok.
> > - fix memory leak in the success case, at the end of while loop.
> > goto cleanup;
> > @@ -1302,7 +1302,15 @@ retry:
> > error = ext4_xattr_block_set(handle, inode, &i, bs);
> > if (error)
> > goto cleanup;
> > + kfree(b_entry_name);
> > + kfree(buffer);
> > + brelse(is->iloc.bh);
> > + kfree(is);
> > + kfree(bs);
> > + brelse(bh);
> > }
> > + up_write(&EXT4_I(inode)->xattr_sem);
> > + return 0;
> >
> > cleanup:
> > kfree(b_entry_name);
>
> I don't think you should have brelse(bh) inside the loop, since it is
> allocated before the loop starts.
>
Ahh right. thanks.
Updated fix.
Fixing memory allocation issue with expand inode extra isize patch.
- use GFP_NOFS instead of GFP_KERNEL to prevent fs reenter
- fix memory leak in the success case, at the end of while loop.
Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx>
---
fs/ext4/xattr.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
Index: linux-2.6.22/fs/ext4/xattr.c
===================================================================
--- linux-2.6.22.orig/fs/ext4/xattr.c 2007-07-16 17:21:14.000000000 -0700
+++ linux-2.6.22/fs/ext4/xattr.c 2007-07-16 17:22:25.000000000 -0700
@@ -1204,8 +1204,8 @@ retry:
unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
unsigned int min_total_size = ~0U;
- is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_KERNEL);
- bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_KERNEL);
+ is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
+ bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
if (!is || !bs) {
error = -ENOMEM;
goto cleanup;
@@ -1251,8 +1251,8 @@ retry:
size = le32_to_cpu(entry->e_value_size);
entry_size = EXT4_XATTR_LEN(entry->e_name_len);
i.name_index = entry->e_name_index,
- buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_KERNEL);
- b_entry_name = kmalloc(entry->e_name_len + 1, GFP_KERNEL);
+ buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
+ b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
if (!buffer || !b_entry_name) {
error = -ENOMEM;
goto cleanup;
@@ -1302,7 +1302,15 @@ retry:
error = ext4_xattr_block_set(handle, inode, &i, bs);
if (error)
goto cleanup;
+ kfree(b_entry_name);
+ kfree(buffer);
+ brelse(is->iloc.bh);
+ kfree(is);
+ kfree(bs);
}
+ brelse(bh);
+ up_write(&EXT4_I(inode)->xattr_sem);
+ return 0;
cleanup:
kfree(b_entry_name);
-
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