linux-toradex.git/fs/ext4/xattr.c, branch v3.7-rc7

ext4: use s_csum_seed instead of i_csum_seed for xattr block

2012-07-09T20:29:27+00:00

In xattr block operation, we use h_refcount to indicate whether the
xattr block is shared among many inodes. And xattr block csum uses
s_csum_seed if it is shared and i_csum_seed if it belongs to
one inode. But this has a problem. So consider the block is shared
first bewteen inode A and B, and B has some xattr update and CoW
the xattr block. When it updates the *old* xattr block(because
of the h_refcount change) and calls ext4_xattr_release_block, we
has no idea that inode A is the real owner of the *old* xattr
block and we can't use the i_csum_seed of inode A either in xattr
block csum calculation. And I don't think we have an easy way to
find inode A.

So this patch just removes the tricky i_csum_seed and we now uses
s_csum_seed every time for the xattr block csum. The corresponding
patch for the e2fsprogs will be sent in another patch.

This is spotted by xfstests 117.

Signed-off-by: Tao Ma 
Signed-off-by: "Theodore Ts'o" 
Acked-by: Darrick J. Wong

ext4: Calculate and verify checksums of extended attribute blocks

2012-04-29T22:43:10+00:00

Calculate and verify the checksums of extended attribute blocks.  This
only applies to separate EA blocks that are pointed to by
inode->i_file_acl (i.e.  external EA blocks); the checksum lives in
the EA header.

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"

ext4: add no_printk argument validation, fix fallout

2012-03-20T03:11:43+00:00

Add argument validation to debug functions.
Use ##__VA_ARGS__.

Fix format and argument mismatches.

Signed-off-by: Joe Perches 
Signed-off-by: "Theodore Ts'o"

ext4: avoid deadlock on sync-mounted FS w/o journal

2012-02-21T04:06:18+00:00

Processes hang forever on a sync-mounted ext2 file system that
is mounted with the ext4 module (default in Fedora 16).

I can reproduce this reliably by mounting an ext2 partition with
"-o sync" and opening a new file an that partition with vim. vim
will hang in "D" state forever.  The same happens on ext4 without
a journal.

I am attaching a small patch here that solves this issue for me.
In the sync mounted case without a journal,
ext4_handle_dirty_metadata() may call sync_dirty_buffer(), which
can't be called with buffer lock held.

Also move mb_cache_entry_release inside lock to avoid race
fixed previously by 8a2bfdcb ext[34]: EA block reference count racing fix
Note too that ext2 fixed this same problem in 2006 with
b2f49033 [PATCH] fix deadlock in ext2

Signed-off-by: Martin.Wilck@ts.fujitsu.com
[sandeen@redhat.com: move mb_cache_entry_release before unlock, edit commit msg]
Signed-off-by: Eric Sandeen 
Signed-off-by: "Theodore Ts'o"

ext4: remove unneeded variable in ext4_xattr_check_block()

2012-02-20T22:53:05+00:00

We could return directly from ext4_xattr_check_block(). Thus, we
shouldn't need to define a 'error' variable.

Signed-off-by: Zheng Liu 
Signed-off-by: "Theodore Ts'o"

ext4: fix race in xattr block allocation path

2011-10-29T14:15:35+00:00

Ceph users reported that when using Ceph on ext4, the filesystem
would often become corrupted, containing inodes with incorrect
i_blocks counters.

I managed to reproduce this with a very hacked-up "streamtest"
binary from the Ceph tree.

Ceph is doing a lot of xattr writes, to out-of-inode blocks.
There is also another thread which does sync_file_range and close,
of the same files.  The problem appears to happen due to this race:

sync/flush thread               xattr-set thread
-----------------               ----------------

do_writepages                   ext4_xattr_set
ext4_da_writepages              ext4_xattr_set_handle
mpage_da_map_blocks             ext4_xattr_block_set
        set DELALLOC_RESERVE
                                ext4_new_meta_blocks
                                        ext4_mb_new_blocks
                                                if (!i_delalloc_reserved_flag)
                                                        vfs_dq_alloc_block
ext4_get_blocks
	down_write(i_data_sem)
        set i_delalloc_reserved_flag
	...
	up_write(i_data_sem)
                                        if (i_delalloc_reserved_flag)
                                                vfs_dq_alloc_block_nofail


In other words, the sync/flush thread pops in and sets
i_delalloc_reserved_flag on the inode, which makes the xattr thread
think that it's in a delalloc path in ext4_new_meta_blocks(),
and add the block for a second time, after already having added
it once in the !i_delalloc_reserved_flag case in ext4_mb_new_blocks

The real problem is that we shouldn't be using the DELALLOC_RESERVED
state flag, and instead we should be passing
EXT4_GET_BLOCKS_DELALLOC_RESERVE down to ext4_map_blocks() instead of
using an inode state flag.  We'll fix this for now with using
i_data_sem to prevent this race, but this is really not the right way
to fix things.

Signed-off-by: Eric Sandeen 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@kernel.org

ext4: use ext4_reserve_inode_write in ext4_xattr_set_handle

2011-10-26T07:32:07+00:00

ext4_mark_iloc_dirty() says:

 * The caller must have previously called ext4_reserve_inode_write().
 * Give this, we know that the caller already has write access to iloc->bh.

ext4_xattr_set_handle, however, just open-codes it.  May as well use
the helper function for consistency.

No bug here, just tidiness.

(Note: on cleanup path, ext4_reserve_inode_write sets
the bh to NULL if it returns an error, and brelse() of 
a null bh is handled gracefully).

Signed-off-by: Eric Sandeen 
Signed-off-by: "Theodore Ts'o"

ext4: add flag to ext4_has_free_blocks

2011-05-25T11:41:26+00:00

This patch adds an allocation request flag to the ext4_has_free_blocks
function which enables the use of reserved blocks.  This will allow a
punch hole to proceed even if the disk is full.  Punching a hole may
require additional blocks to first split the extents.

Because ext4_has_free_blocks is a low level function, the flag needs
to be passed down through several functions listed below:

ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_ext_split
ext4_ext_new_meta_block
ext4_mb_new_blocks
ext4_claim_free_blocks
ext4_has_free_blocks

[ext4 punch hole patch series 1/5 v7]

Signed-off-by: Allison Henderson 
Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Mingming Cao

ext4: unify the ext4_handle_release_buffer() api

2011-03-21T02:57:02+00:00

There are two wrapper functions which do exactly the same thing:
ext4_journal_release_buffer(), and ext4_handle_release_buffer().  In
addition, ext4_xattr_block_set() calls jbd2_journal_release_buffer()
directly.

Unify all of the code to use ext4_handle_release_buffer(), and get rid
of ext4_journal_release_buffer().

Signed-off-by: Amir Goldstein 
Signed-off-by: "Theodore Ts'o"

ext4: Fix sparse warning: Using plain integer as NULL pointer

2011-02-22T02:01:42+00:00

This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.

Signed-off-by: Peter Huewe 
Signed-off-by: "Theodore Ts'o"