linux/fs/xfs/xfs_attr_inactive.c
Dave Chinner 6dfe5a049f xfs: xfs_attr_inactive leaves inconsistent attr fork state behind
xfs_attr_inactive() is supposed to clean up the attribute fork when
the inode is being freed. While it removes attribute fork extents,
it completely ignores attributes in local format, which means that
there can still be active attributes on the inode after
xfs_attr_inactive() has run.

This leads to problems with concurrent inode writeback - the in-core
inode attribute fork is removed without locking on the assumption
that nothing will be attempting to access the attribute fork after a
call to xfs_attr_inactive() because it isn't supposed to exist on
disk any more.

To fix this, make xfs_attr_inactive() completely remove all traces
of the attribute fork from the inode, regardless of it's state.
Further, also remove the in-core attribute fork structure safely so
that there is nothing further that needs to be done by callers to
clean up the attribute fork. This means we can remove the in-core
and on-disk attribute forks atomically.

Also, on error simply remove the in-memory attribute fork. There's
nothing that can be done with it once we have failed to remove the
on-disk attribute fork, so we may as well just blow it away here
anyway.

cc: <stable@vger.kernel.org> # 3.12 to 4.0
Reported-by: Waiman Long <waiman.long@hp.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-05-29 07:40:08 +10:00

466 lines
12 KiB
C

/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_attr_remote.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"
#include "xfs_quota.h"
#include "xfs_trace.h"
#include "xfs_dir2.h"
/*
* Look at all the extents for this logical region,
* invalidate any buffers that are incore/in transactions.
*/
STATIC int
xfs_attr3_leaf_freextent(
struct xfs_trans **trans,
struct xfs_inode *dp,
xfs_dablk_t blkno,
int blkcnt)
{
struct xfs_bmbt_irec map;
struct xfs_buf *bp;
xfs_dablk_t tblkno;
xfs_daddr_t dblkno;
int tblkcnt;
int dblkcnt;
int nmap;
int error;
/*
* Roll through the "value", invalidating the attribute value's
* blocks.
*/
tblkno = blkno;
tblkcnt = blkcnt;
while (tblkcnt > 0) {
/*
* Try to remember where we decided to put the value.
*/
nmap = 1;
error = xfs_bmapi_read(dp, (xfs_fileoff_t)tblkno, tblkcnt,
&map, &nmap, XFS_BMAPI_ATTRFORK);
if (error) {
return error;
}
ASSERT(nmap == 1);
ASSERT(map.br_startblock != DELAYSTARTBLOCK);
/*
* If it's a hole, these are already unmapped
* so there's nothing to invalidate.
*/
if (map.br_startblock != HOLESTARTBLOCK) {
dblkno = XFS_FSB_TO_DADDR(dp->i_mount,
map.br_startblock);
dblkcnt = XFS_FSB_TO_BB(dp->i_mount,
map.br_blockcount);
bp = xfs_trans_get_buf(*trans,
dp->i_mount->m_ddev_targp,
dblkno, dblkcnt, 0);
if (!bp)
return -ENOMEM;
xfs_trans_binval(*trans, bp);
/*
* Roll to next transaction.
*/
error = xfs_trans_roll(trans, dp);
if (error)
return error;
}
tblkno += map.br_blockcount;
tblkcnt -= map.br_blockcount;
}
return 0;
}
/*
* Invalidate all of the "remote" value regions pointed to by a particular
* leaf block.
* Note that we must release the lock on the buffer so that we are not
* caught holding something that the logging code wants to flush to disk.
*/
STATIC int
xfs_attr3_leaf_inactive(
struct xfs_trans **trans,
struct xfs_inode *dp,
struct xfs_buf *bp)
{
struct xfs_attr_leafblock *leaf;
struct xfs_attr3_icleaf_hdr ichdr;
struct xfs_attr_leaf_entry *entry;
struct xfs_attr_leaf_name_remote *name_rmt;
struct xfs_attr_inactive_list *list;
struct xfs_attr_inactive_list *lp;
int error;
int count;
int size;
int tmp;
int i;
struct xfs_mount *mp = bp->b_target->bt_mount;
leaf = bp->b_addr;
xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
/*
* Count the number of "remote" value extents.
*/
count = 0;
entry = xfs_attr3_leaf_entryp(leaf);
for (i = 0; i < ichdr.count; entry++, i++) {
if (be16_to_cpu(entry->nameidx) &&
((entry->flags & XFS_ATTR_LOCAL) == 0)) {
name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
if (name_rmt->valueblk)
count++;
}
}
/*
* If there are no "remote" values, we're done.
*/
if (count == 0) {
xfs_trans_brelse(*trans, bp);
return 0;
}
/*
* Allocate storage for a list of all the "remote" value extents.
*/
size = count * sizeof(xfs_attr_inactive_list_t);
list = kmem_alloc(size, KM_SLEEP);
/*
* Identify each of the "remote" value extents.
*/
lp = list;
entry = xfs_attr3_leaf_entryp(leaf);
for (i = 0; i < ichdr.count; entry++, i++) {
if (be16_to_cpu(entry->nameidx) &&
((entry->flags & XFS_ATTR_LOCAL) == 0)) {
name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
if (name_rmt->valueblk) {
lp->valueblk = be32_to_cpu(name_rmt->valueblk);
lp->valuelen = xfs_attr3_rmt_blocks(dp->i_mount,
be32_to_cpu(name_rmt->valuelen));
lp++;
}
}
}
xfs_trans_brelse(*trans, bp); /* unlock for trans. in freextent() */
/*
* Invalidate each of the "remote" value extents.
*/
error = 0;
for (lp = list, i = 0; i < count; i++, lp++) {
tmp = xfs_attr3_leaf_freextent(trans, dp,
lp->valueblk, lp->valuelen);
if (error == 0)
error = tmp; /* save only the 1st errno */
}
kmem_free(list);
return error;
}
/*
* Recurse (gasp!) through the attribute nodes until we find leaves.
* We're doing a depth-first traversal in order to invalidate everything.
*/
STATIC int
xfs_attr3_node_inactive(
struct xfs_trans **trans,
struct xfs_inode *dp,
struct xfs_buf *bp,
int level)
{
xfs_da_blkinfo_t *info;
xfs_da_intnode_t *node;
xfs_dablk_t child_fsb;
xfs_daddr_t parent_blkno, child_blkno;
int error, i;
struct xfs_buf *child_bp;
struct xfs_da_node_entry *btree;
struct xfs_da3_icnode_hdr ichdr;
/*
* Since this code is recursive (gasp!) we must protect ourselves.
*/
if (level > XFS_DA_NODE_MAXDEPTH) {
xfs_trans_brelse(*trans, bp); /* no locks for later trans */
return -EIO;
}
node = bp->b_addr;
dp->d_ops->node_hdr_from_disk(&ichdr, node);
parent_blkno = bp->b_bn;
if (!ichdr.count) {
xfs_trans_brelse(*trans, bp);
return 0;
}
btree = dp->d_ops->node_tree_p(node);
child_fsb = be32_to_cpu(btree[0].before);
xfs_trans_brelse(*trans, bp); /* no locks for later trans */
/*
* If this is the node level just above the leaves, simply loop
* over the leaves removing all of them. If this is higher up
* in the tree, recurse downward.
*/
for (i = 0; i < ichdr.count; i++) {
/*
* Read the subsidiary block to see what we have to work with.
* Don't do this in a transaction. This is a depth-first
* traversal of the tree so we may deal with many blocks
* before we come back to this one.
*/
error = xfs_da3_node_read(*trans, dp, child_fsb, -2, &child_bp,
XFS_ATTR_FORK);
if (error)
return error;
if (child_bp) {
/* save for re-read later */
child_blkno = XFS_BUF_ADDR(child_bp);
/*
* Invalidate the subtree, however we have to.
*/
info = child_bp->b_addr;
switch (info->magic) {
case cpu_to_be16(XFS_DA_NODE_MAGIC):
case cpu_to_be16(XFS_DA3_NODE_MAGIC):
error = xfs_attr3_node_inactive(trans, dp,
child_bp, level + 1);
break;
case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
error = xfs_attr3_leaf_inactive(trans, dp,
child_bp);
break;
default:
error = -EIO;
xfs_trans_brelse(*trans, child_bp);
break;
}
if (error)
return error;
/*
* Remove the subsidiary block from the cache
* and from the log.
*/
error = xfs_da_get_buf(*trans, dp, 0, child_blkno,
&child_bp, XFS_ATTR_FORK);
if (error)
return error;
xfs_trans_binval(*trans, child_bp);
}
/*
* If we're not done, re-read the parent to get the next
* child block number.
*/
if (i + 1 < ichdr.count) {
error = xfs_da3_node_read(*trans, dp, 0, parent_blkno,
&bp, XFS_ATTR_FORK);
if (error)
return error;
child_fsb = be32_to_cpu(btree[i + 1].before);
xfs_trans_brelse(*trans, bp);
}
/*
* Atomically commit the whole invalidate stuff.
*/
error = xfs_trans_roll(trans, dp);
if (error)
return error;
}
return 0;
}
/*
* Indiscriminately delete the entire attribute fork
*
* Recurse (gasp!) through the attribute nodes until we find leaves.
* We're doing a depth-first traversal in order to invalidate everything.
*/
int
xfs_attr3_root_inactive(
struct xfs_trans **trans,
struct xfs_inode *dp)
{
struct xfs_da_blkinfo *info;
struct xfs_buf *bp;
xfs_daddr_t blkno;
int error;
/*
* Read block 0 to see what we have to work with.
* We only get here if we have extents, since we remove
* the extents in reverse order the extent containing
* block 0 must still be there.
*/
error = xfs_da3_node_read(*trans, dp, 0, -1, &bp, XFS_ATTR_FORK);
if (error)
return error;
blkno = bp->b_bn;
/*
* Invalidate the tree, even if the "tree" is only a single leaf block.
* This is a depth-first traversal!
*/
info = bp->b_addr;
switch (info->magic) {
case cpu_to_be16(XFS_DA_NODE_MAGIC):
case cpu_to_be16(XFS_DA3_NODE_MAGIC):
error = xfs_attr3_node_inactive(trans, dp, bp, 1);
break;
case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
error = xfs_attr3_leaf_inactive(trans, dp, bp);
break;
default:
error = -EIO;
xfs_trans_brelse(*trans, bp);
break;
}
if (error)
return error;
/*
* Invalidate the incore copy of the root block.
*/
error = xfs_da_get_buf(*trans, dp, 0, blkno, &bp, XFS_ATTR_FORK);
if (error)
return error;
xfs_trans_binval(*trans, bp); /* remove from cache */
/*
* Commit the invalidate and start the next transaction.
*/
error = xfs_trans_roll(trans, dp);
return error;
}
/*
* xfs_attr_inactive kills all traces of an attribute fork on an inode. It
* removes both the on-disk and in-memory inode fork. Note that this also has to
* handle the condition of inodes without attributes but with an attribute fork
* configured, so we can't use xfs_inode_hasattr() here.
*
* The in-memory attribute fork is removed even on error.
*/
int
xfs_attr_inactive(
struct xfs_inode *dp)
{
struct xfs_trans *trans;
struct xfs_mount *mp;
int cancel_flags = 0;
int lock_mode = XFS_ILOCK_SHARED;
int error = 0;
mp = dp->i_mount;
ASSERT(! XFS_NOT_DQATTACHED(mp, dp));
xfs_ilock(dp, lock_mode);
if (!XFS_IFORK_Q(dp))
goto out_destroy_fork;
xfs_iunlock(dp, lock_mode);
/*
* Start our first transaction of the day.
*
* All future transactions during this code must be "chained" off
* this one via the trans_dup() call. All transactions will contain
* the inode, and the inode will always be marked with trans_ihold().
* Since the inode will be locked in all transactions, we must log
* the inode in every transaction to let it float upward through
* the log.
*/
lock_mode = 0;
trans = xfs_trans_alloc(mp, XFS_TRANS_ATTRINVAL);
error = xfs_trans_reserve(trans, &M_RES(mp)->tr_attrinval, 0, 0);
if (error)
goto out_cancel;
lock_mode = XFS_ILOCK_EXCL;
cancel_flags = XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT;
xfs_ilock(dp, lock_mode);
if (!XFS_IFORK_Q(dp))
goto out_cancel;
/*
* No need to make quota reservations here. We expect to release some
* blocks, not allocate, in the common case.
*/
xfs_trans_ijoin(trans, dp, 0);
/* invalidate and truncate the attribute fork extents */
if (dp->i_d.di_aformat != XFS_DINODE_FMT_LOCAL) {
error = xfs_attr3_root_inactive(&trans, dp);
if (error)
goto out_cancel;
error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
if (error)
goto out_cancel;
}
/* Reset the attribute fork - this also destroys the in-core fork */
xfs_attr_fork_remove(dp, trans);
error = xfs_trans_commit(trans, XFS_TRANS_RELEASE_LOG_RES);
xfs_iunlock(dp, lock_mode);
return error;
out_cancel:
xfs_trans_cancel(trans, cancel_flags);
out_destroy_fork:
/* kill the in-core attr fork before we drop the inode lock */
if (dp->i_afp)
xfs_idestroy_fork(dp, XFS_ATTR_FORK);
if (lock_mode)
xfs_iunlock(dp, lock_mode);
return error;
}