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linux/fs/xfs/xfs_attr_item.h

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xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
/* SPDX-License-Identifier: GPL-2.0-or-later
*
* Copyright (C) 2022 Oracle. All Rights Reserved.
* Author: Allison Henderson <allison.henderson@oracle.com>
*/
#ifndef __XFS_ATTR_ITEM_H__
#define __XFS_ATTR_ITEM_H__
/* kernel only ATTRI/ATTRD definitions */
struct xfs_mount;
struct kmem_zone;
xfs: share xattr name and value buffers when logging xattr updates While running xfs/297 and generic/642, I noticed a crash in xfs_attri_item_relog when it tries to copy the attr name to the new xattri log item. I think what happened here was that we called ->iop_commit on the old attri item (which nulls out the pointers) as part of a log force at the same time that a chained attr operation was ongoing. The system was busy enough that at some later point, the defer ops operation decided it was necessary to relog the attri log item, but as we've detached the name buffer from the old attri log item, we can't copy it to the new one, and kaboom. I think there's a broader refcounting problem with LARP mode -- the setxattr code can return to userspace before the CIL actually formats and commits the log item, which results in a UAF bug. Therefore, the xattr log item needs to be able to retain a reference to the name and value buffers until the log items have completely cleared the log. Furthermore, each time we create an intent log item, we allocate new memory and (re)copy the contents; sharing here would be very useful. Solve the UAF and the unnecessary memory allocations by having the log code create a single refcounted buffer to contain the name and value contents. This buffer can be passed from old to new during a relog operation, and the logging code can (optionally) attach it to the xfs_attr_item for reuse when LARP mode is enabled. This also fixes a problem where the xfs_attri_log_item objects weren't being freed back to the same cache where they came from. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-22 22:43:46 +00:00
struct xfs_attri_log_nameval {
struct xfs_log_iovec name;
struct xfs_log_iovec value;
refcount_t refcount;
/* name and value follow the end of this struct */
};
xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
/*
* This is the "attr intention" log item. It is used to log the fact that some
* extended attribute operations need to be processed. An operation is
* currently either a set or remove. Set or remove operations are described by
xfs: rename struct xfs_attr_item to xfs_attr_intent Everywhere else in XFS, structures that capture the state of an ongoing deferred work item all have names that end with "_intent". The new extended attribute deferred work items are not named as such, so fix it to follow the naming convention used elsewhere. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-22 06:00:26 +00:00
* the xfs_attr_intent which may be logged to this intent.
xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
*
* During a normal attr operation, name and value point to the name and value
* fields of the caller's xfs_da_args structure. During a recovery, the name
* and value buffers are copied from the log, and stored in a trailing buffer
xfs: rename struct xfs_attr_item to xfs_attr_intent Everywhere else in XFS, structures that capture the state of an ongoing deferred work item all have names that end with "_intent". The new extended attribute deferred work items are not named as such, so fix it to follow the naming convention used elsewhere. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-22 06:00:26 +00:00
* attached to the xfs_attr_intent until they are committed. They are freed
* when the xfs_attr_intent itself is freed when the work is done.
xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
*/
struct xfs_attri_log_item {
struct xfs_log_item attri_item;
atomic_t attri_refcount;
xfs: share xattr name and value buffers when logging xattr updates While running xfs/297 and generic/642, I noticed a crash in xfs_attri_item_relog when it tries to copy the attr name to the new xattri log item. I think what happened here was that we called ->iop_commit on the old attri item (which nulls out the pointers) as part of a log force at the same time that a chained attr operation was ongoing. The system was busy enough that at some later point, the defer ops operation decided it was necessary to relog the attri log item, but as we've detached the name buffer from the old attri log item, we can't copy it to the new one, and kaboom. I think there's a broader refcounting problem with LARP mode -- the setxattr code can return to userspace before the CIL actually formats and commits the log item, which results in a UAF bug. Therefore, the xattr log item needs to be able to retain a reference to the name and value buffers until the log items have completely cleared the log. Furthermore, each time we create an intent log item, we allocate new memory and (re)copy the contents; sharing here would be very useful. Solve the UAF and the unnecessary memory allocations by having the log code create a single refcounted buffer to contain the name and value contents. This buffer can be passed from old to new during a relog operation, and the logging code can (optionally) attach it to the xfs_attr_item for reuse when LARP mode is enabled. This also fixes a problem where the xfs_attri_log_item objects weren't being freed back to the same cache where they came from. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-22 22:43:46 +00:00
struct xfs_attri_log_nameval *attri_nameval;
xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
struct xfs_attri_log_format attri_format;
};
/*
* This is the "attr done" log item. It is used to log the fact that some attrs
* earlier mentioned in an attri item have been freed.
*/
struct xfs_attrd_log_item {
struct xfs_log_item attrd_item;
struct xfs_attri_log_item *attrd_attrip;
struct xfs_attrd_log_format attrd_format;
};
xfs: put attr[id] log item cache init with the others Initialize and destroy the xattr log item caches in the same places that we do all the other log item caches. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-22 05:59:48 +00:00
extern struct kmem_cache *xfs_attri_cache;
extern struct kmem_cache *xfs_attrd_cache;
xfs: Set up infrastructure for log attribute replay Currently attributes are modified directly across one or more transactions. But they are not logged or replayed in the event of an error. The goal of log attr replay is to enable logging and replaying of attribute operations using the existing delayed operations infrastructure. This will later enable the attributes to become part of larger multi part operations that also must first be recorded to the log. This is mostly of interest in the scheme of parent pointers which would need to maintain an attribute containing parent inode information any time an inode is moved, created, or removed. Parent pointers would then be of interest to any feature that would need to quickly derive an inode path from the mount point. Online scrub, nfs lookups and fs grow or shrink operations are all features that could take advantage of this. This patch adds two new log item types for setting or removing attributes as deferred operations. The xfs_attri_log_item will log an intent to set or remove an attribute. The corresponding xfs_attrd_log_item holds a reference to the xfs_attri_log_item and is freed once the transaction is done. Both log items use a generic xfs_attr_log_format structure that contains the attribute name, value, flags, inode, and an op_flag that indicates if the operations is a set or remove. [dchinner: added extra little bits needed for intent whiteouts] Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 02:41:02 +00:00
#endif /* __XFS_ATTR_ITEM_H__ */
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