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2022-05-12xfs: detect empty attr leaf blocks in xfs_attr3_leaf_verifyDave Chinner
xfs_repair flags these as a corruption error, so the verifier should catch software bugs that result in empty leaf blocks being written to disk, too. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: ATTR_REPLACE algorithm with LARP enabled needs reworkDave Chinner
We can't use the same algorithm for replacing an existing attribute when logging attributes. The existing algorithm is essentially: 1. create new attr w/ INCOMPLETE 2. atomically flip INCOMPLETE flags between old + new attribute 3. remove old attr which is marked w/ INCOMPLETE This algorithm guarantees that we see either the old or new attribute, and if we fail after the atomic flag flip, we don't have to recover the removal of the old attr because we never see INCOMPLETE attributes in lookups. For logged attributes, however, this does not work. The logged attribute intents do not track the work that has been done as the transaction rolls, and hence the only recovery mechanism we have is "run the replace operation from scratch". This is further exacerbated by the attempt to avoid needing the INCOMPLETE flag to create an atomic swap. This means we can create a second active attribute of the same name before we remove the original. If we fail at any point after the create but before the removal has completed, we end up with duplicate attributes in the attr btree and recovery only tries to replace one of them. There are several other failure modes where we can leave partially allocated remote attributes that expose stale data, partially free remote attributes that enable UAF based stale data exposure, etc. TO fix this, we need a different algorithm for replace operations when LARP is enabled. Luckily, it's not that complex if we take the right first step. That is, the first thing we log is the attri intent with the new name/value pair and mark the old attr as INCOMPLETE in the same transaction. From there, we then remove the old attr and keep relogging the new name/value in the intent, such that we always know that we have to create the new attr in recovery. Once the old attr is removed, we then run a normal ATTR_CREATE operation relogging the intent as we go. If the new attr is local, then it gets created in a single atomic transaction that also logs the final intent done. If the new attr is remote, the we set INCOMPLETE on the new attr while we allocate and set the remote value, and then we clear the INCOMPLETE flag at in the last transaction taht logs the final intent done. If we fail at any point in this algorithm, log recovery will always see the same state on disk: the new name/value in the intent, and either an INCOMPLETE attr or no attr in the attr btree. If we find an INCOMPLETE attr, we run the full replace starting with removing the INCOMPLETE attr. If we don't find it, then we simply create the new attr. Notably, recovery of a failed create that has an INCOMPLETE flag set is now the same - we start with the lookup of the INCOMPLETE attr, and if that exists then we do the full replace recovery process, otherwise we just create the new attr. Hence changing the way we do the replace operation when LARP is enabled allows us to use the same log recovery algorithm for both the ATTR_CREATE and ATTR_REPLACE operations. This is also the same algorithm we use for runtime ATTR_REPLACE operations (except for the step setting up the initial conditions). The result is that: - ATTR_CREATE uses the same algorithm regardless of whether LARP is enabled or not - ATTR_REPLACE with larp=0 is identical to the old algorithm - ATTR_REPLACE with larp=1 runs an unmodified attr removal algorithm from the larp=0 code and then runs the unmodified ATTR_CREATE code. - log recovery when larp=1 runs the same ATTR_REPLACE algorithm as it uses at runtime. Because the state machine is now quite clean, changing the algorithm is really just a case of changing the initial state and how the states link together for the ATTR_REPLACE case. Hence it's not a huge amount of code for what is a fairly substantial rework of the attr logging and recovery algorithm.... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: use XFS_DA_OP flags in deferred attr opsDave Chinner
We currently store the high level attr operation in args->attr_flags. This field contains what the VFS is telling us to do, but don't necessarily match what we are doing in the low level modification state machine. e.g. XATTR_REPLACE implies both XFS_DA_OP_ADDNAME and XFS_DA_OP_RENAME because it is doing both a remove and adding a new attr. However, deep in the individual state machine operations, we check errors against this high level VFS op flags, not the low level XFS_DA_OP flags. Indeed, we don't even have a low level flag for a REMOVE operation, so the only way we know we are doing a remove is the complete absence of XATTR_REPLACE, XATTR_CREATE, XFS_DA_OP_ADDNAME and XFS_DA_OP_RENAME. And because there are other flags in these fields, this is a pain to check if we need to. As the XFS_DA_OP flags are only needed once the deferred operations are set up, set these flags appropriately when we set the initial operation state. We also introduce a XFS_DA_OP_REMOVE flag to make it easy to know that we are doing a remove operation. With these, we can remove the use of XATTR_REPLACE and XATTR_CREATE in low level lookup operations, and manipulate the low level flags according to the low level context that is operating. e.g. log recovery does not have a VFS xattr operation state to copy into args->attr_flags, and the low level state machine ops we do for recovery do not match the high level VFS operations that were in progress when the system failed... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: remove xfs_attri_remove_iterDave Chinner
xfs_attri_remove_iter is not used anymore, so remove it and all the infrastructure it uses and is needed to drive it. THe xfs_attr_refillstate() function now throws an unused warning, so isolate the xfs_attr_fillstate()/xfs_attr_refillstate() code pair with an #if 0 and a comment explaining why we want to keep this code and restore the optimisation it provides in the near future. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: switch attr remove to xfs_attri_set_iterDave Chinner
Now that xfs_attri_set_iter() has initial states for removing attributes, switch the pure attribute removal code over to using it. This requires attrs being removed to always be marked as INCOMPLETE before we start the removal due to the fact we look up the attr to remove again in xfs_attr_node_remove_attr(). Note: this drops the fillstate/refillstate optimisations from the remove path that avoid having to look up the path again after setting the incomplete flag and removing remote attrs. Restoring that optimisation to this path is future Dave's problem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: introduce attr remove initial states into xfs_attr_set_iterDave Chinner
We need to merge the add and remove code paths to enable safe recovery of replace operations. Hoist the initial remove states from xfs_attr_remove_iter into xfs_attr_set_iter. We will make use of them in the next patches. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: xfs_attr_set_iter() does not need to return EAGAINDave Chinner
Now that the full xfs_attr_set_iter() state machine always terminates with either the state being XFS_DAS_DONE on success or an error on failure, we can get rid of the need for it to return -EAGAIN whenever it needs to roll the transaction before running the next state. That is, we don't need to spray -EAGAIN return states everywhere, the caller just check the state machine state for completion to determine what action should be taken next. This greatly simplifies the code within the state machine implementation as it now only has to handle 0 for success or -errno for error and it doesn't need to tell the caller to retry. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: clean up final attr removal in xfs_attr_set_iterDave Chinner
Clean up the final leaf/node states in xfs_attr_set_iter() to further simplify the high level state machine and to set the completion state correctly. As we are adding a separate state for node format removal, we need to ensure that node formats are collapsed back to shortform or empty correctly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: remote xattr removal in xfs_attr_set_iter() is conditionalDave Chinner
We may not have a remote value for the old xattr we have to remove, so skip over the remote value removal states and go straight to the xattr name removal in the leaf/node block. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: XFS_DAS_LEAF_REPLACE state only needed if !LARPDave Chinner
We can skip the REPLACE state when LARP is enabled, but that means the XFS_DAS_FLIP_LFLAG state is now poorly named - it indicates something that has been done rather than what the state is going to do. Rename it to "REMOVE_OLD" to indicate that we are now going to perform removal of the old attr. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: split remote attr setting out from replace pathDave Chinner
When we set a new xattr, we have three exit paths: 1. nothing else to do 2. allocate and set the remote xattr value 3. perform the rest of a replace operation Currently we push both 2 and 3 into the same state, regardless of whether we just set a remote attribute or not. Once we've set the remote xattr, we have two exit states: 1. nothing else to do 2. perform the rest of a replace operation Hence we can split the remote xattr allocation and setting into their own states and factor it out of xfs_attr_set_iter() to further clean up the state machine and the implementation of the state machine. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: consolidate leaf/node states in xfs_attr_set_iterDave Chinner
The operations performed from XFS_DAS_FOUND_LBLK through to XFS_DAS_RM_LBLK are now identical to XFS_DAS_FOUND_NBLK through to XFS_DAS_RM_NBLK. We can collapse these down into a single set of code. To do this, define the states that leaf and node run through as separate sets of sequential states. Then as we move to the next state, we can use increments rather than specific state assignments to move through the states. This means the state progression is set by the initial state that enters the series and we don't need to duplicate the code anymore. At the exit point of the series we need to select the correct leaf or node state, but that can also be done by state increment rather than assignment. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: kill XFS_DAC_LEAF_ADDNAME_INITDave Chinner
We re-enter the XFS_DAS_FOUND_LBLK state when we have to allocate multiple extents for a remote xattr. We currently have a flag called XFS_DAC_LEAF_ADDNAME_INIT to avoid running the remote attr hole finding code more than once. However, for the node format tree, we have a separate state for this so we never reenter the state machine at XFS_DAS_FOUND_NBLK and so it does not need a special flag to skip over the remote attr hold finding code. Convert the leaf block code to use the same state machine as the node blocks and kill the XFS_DAC_LEAF_ADDNAME_INIT flag. This further points out that this "ALLOC" state is only traversed if we have remote xattrs or we are doing a rename operation. Rename both the leaf and node alloc states to _ALLOC_RMT to indicate they are iterating to do allocation of remote xattr blocks. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-12xfs: separate out initial attr_set statesDave Chinner
We current use XFS_DAS_UNINIT for several steps in the attr_set state machine. We use it for setting shortform xattrs, converting from shortform to leaf, leaf add, leaf-to-node and leaf add. All of these things are essentially known before we start the state machine iterating, so we really should separate them out: XFS_DAS_SF_ADD: - tries to do a shortform add - on success -> done - on ENOSPC converts to leaf, -> XFS_DAS_LEAF_ADD - on error, dies. XFS_DAS_LEAF_ADD: - tries to do leaf add - on success: - inline attr -> done - remote xattr || REPLACE -> XFS_DAS_FOUND_LBLK - on ENOSPC converts to node, -> XFS_DAS_NODE_ADD - on error, dies XFS_DAS_NODE_ADD: - tries to do node add - on success: - inline attr -> done - remote xattr || REPLACE -> XFS_DAS_FOUND_NBLK - on error, dies This makes it easier to understand how the state machine starts up and sets us up on the path to further state machine simplifications. This also converts the DAS state tracepoints to use strings rather than numbers, as converting between enums and numbers requires manual counting rather than just reading the name. This also introduces a XFS_DAS_DONE state so that we can trace successful operation completions easily. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: remove warning counters from struct xfs_dquot_resCatherine Hoang
Warning counts are not used anywhere in the kernel. In addition, there are no use cases, test coverage, or documentation for this functionality. Remove the 'warnings' field from struct xfs_dquot_res and any other related code. Signed-off-by: Catherine Hoang <catherine.hoang@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: rework deferred attribute operation setupDave Chinner
Logged attribute intents only have set and remove types - there is no separate intent type for a replace operation. We should have a separate type for a replace operation, as it needs to perform operations that neither SET or REMOVE can perform. Add this type to the intent items and rearrange the deferred operation setup to reflect the different operations we are performing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: make xattri_leaf_bp more usefulDave Chinner
We currently set it and hold it when converting from short to leaf form, then release it only to immediately look it back up again to do the leaf insert. Do a bit of refactoring to xfs_attr_leaf_try_add() to avoid this messy handling of the newly allocated leaf buffer. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: avoid empty xattr transaction when attrs are inlineDave Chinner
generic/642 triggered a reproducable assert failure in xlog_cil_commit() that resulted from a xfs_attr_set() committing an empty but dirty transaction. When the CIL is empty and this occurs, xlog_cil_commit() tries a background push and this triggers a "pushing an empty CIL" assert. XFS: Assertion failed: !list_empty(&cil->xc_cil), file: fs/xfs/xfs_log_cil.c, line: 1274 Call Trace: <TASK> xlog_cil_commit+0xa5a/0xad0 __xfs_trans_commit+0xb8/0x330 xfs_trans_commit+0x10/0x20 xfs_attr_set+0x3e2/0x4c0 xfs_xattr_set+0x8d/0xe0 __vfs_setxattr+0x6b/0x90 __vfs_setxattr_noperm+0x76/0x220 __vfs_setxattr_locked+0xdf/0x100 vfs_setxattr+0x94/0x170 setxattr+0x110/0x200 path_setxattr+0xbf/0xe0 __x64_sys_setxattr+0x2b/0x30 do_syscall_64+0x35/0x80 The problem is related to the breakdown of attribute addition in xfs_attr_set_iter() and how it is called from deferred operations. When we have a pure leaf xattr insert, we add the xattr to the leaf and set the next state to XFS_DAS_FOUND_LBLK and return -EAGAIN. This requeues the xattr defered work, rolls the transaction and runs xfs_attr_set_iter() again. This then checks the xattr for being remote (it's not) and whether a replace op is being done (this is a create op) and if neither are true it returns without having done anything. xfs_xattri_finish_update() then unconditionally sets the transaction dirty, and the deferops finishes and returns to __xfs_trans_commit() which sees the transaction dirty and tries to commit it by calling xlog_cil_commit(). The transaction is empty, and then the assert fires if this happens when the CIL is empty. This patch addresses the structure of xfs_attr_set_iter() that requires re-entry on leaf add even when nothing will be done. This gets rid of the trailing empty transaction and so doesn't trigger the XFS_TRANS_DIRTY assignment in xfs_xattri_finish_update() incorrectly. Addressing that is for a different patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson<allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: add leaf to node error tagAllison Henderson
Add an error tag on xfs_attr3_leaf_to_node to test log attribute recovery and replay. Signed-off-by: Catherine Hoang <catherine.hoang@oracle.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: add leaf split error tagAllison Henderson
Add an error tag on xfs_da3_split to test log attribute recovery and replay. Signed-off-by: Catherine Hoang <catherine.hoang@oracle.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Add helper function xfs_init_attr_transAllison Henderson
Quick helper function to collapse duplicate code to initialize transactions for attributes Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Suggested-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Add helper function xfs_attr_leaf_addnameAllison Henderson
This patch adds a helper function xfs_attr_leaf_addname. While this does help to break down xfs_attr_set_iter, it does also hoist out some of the state management. This patch has been moved to the end of the clean up series for further discussion. Suggested-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Merge xfs_delattr_context into xfs_attr_itemAllison Henderson
This is a clean up patch that merges xfs_delattr_context into xfs_attr_item. Now that the refactoring is complete and the delayed operation infrastructure is in place, we can combine these to eliminate the extra struct Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Add larp debug optionAllison Henderson
This patch adds a debug option to enable log attribute replay. Eventually this can be removed when delayed attrs becomes permanent. 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>
2022-05-11xfs: Add log attribute error tagAllison Henderson
This patch adds an error tag that we can use to test log attribute recovery and replay Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Remove unused xfs_attr_*_argsAllison Henderson
Remove xfs_attr_set_args, xfs_attr_remove_args, and xfs_attr_trans_roll. These high level loops are now driven by the delayed operations code, and can be removed. Additionally collapse in the leaf_bp parameter of xfs_attr_set_iter since we only have one caller that passes dac->leaf_bp Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-11xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferredAllison Henderson
These routines set up and queue a new deferred attribute operations. These functions are meant to be called by any routine needing to initiate a deferred attribute operation as opposed to the existing inline operations. New helper function xfs_attr_item_init also added. Finally enable delayed attributes in xfs_attr_set and xfs_attr_remove. Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-09xfs: Skip flip flags for delayed attrsAllison Henderson
This is a clean up patch that skips the flip flag logic for delayed attr renames. Since the log replay keeps the inode locked, we do not need to worry about race windows with attr lookups. So we can skip over flipping the flag and the extra transaction roll for it Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-09xfs: Implement attr logging and replayAllison Henderson
This patch adds the needed routines to create, log and recover logged extended attribute intents. 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>
2022-05-04xfs: Set up infrastructure for log attribute replayAllison Henderson
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>
2022-05-04xfs: Return from xfs_attr_set_iter if there are no more rmtblks to processAllison Henderson
During an attr rename operation, blocks are saved for later removal as rmtblkno2. The rmtblkno is used in the case of needing to alloc more blocks if not enough were available. However, in the case that no further blocks need to be added or removed, we can return as soon as xfs_attr_node_addname completes, rather than rolling the transaction with an -EAGAIN return. This extra loop does not hurt anything right now, but it will be a problem later when we get into log items because we end up with an empty log transaction. So, add a simple check to cut out the unneeded iteration. 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>
2022-05-04xfs: Fix double unlock in defer capture codeAllison Henderson
The new deferred attr patch set uncovered a double unlock in the recent port of the defer ops capture and continue code. During log recovery, we're allowed to hold buffers to a transaction that's being used to replay an intent item. When we capture the resources as part of scheduling a continuation of an intent chain, we call xfs_buf_hold to retain our reference to the buffer beyond the transaction commit, but we do /not/ call xfs_trans_bhold to maintain the buffer lock. This means that xfs_defer_ops_continue needs to relock the buffers before xfs_defer_restore_resources joins then tothe new transaction. Additionally, the buffers should not be passed back via the dres structure since they need to remain locked unlike the inodes. So simply set dr_bufs to zero after populating the dres structure. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Chandan Babu R <chandan.babu@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04Merge branch 'guilt/xfs-5.19-fuzz-fixes' into xfs-5.19-for-nextDave Chinner
2022-05-04Merge tag 'reflink-speedups-5.19_2022-04-28' of ↵Dave Chinner
git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.19-for-next xfs: fix reflink inefficiencies As Dave Chinner has complained about on IRC, there are a couple of things about reflink that are very inefficient. First of all, we limited the size of all bunmapi operations to avoid flooding the log with defer ops in the worst case, but recent changes to the defer ops code have solved that problem, so get rid of the bunmapi length clamp. Second, the log reservations for reflink operations are far far larger than they need to be. Shrink them to exactly what we need to handle each deferred RUI and CUI log item, and no more. Also reduce logcount because we don't need 8 rolls per operation. Introduce a transaction reservation compatibility layer to avoid changing the minimum log size calculations. Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04Merge tag 'rmap-speedups-5.19_2022-04-28' of ↵Dave Chinner
git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.19-for-next xfs: fix rmap inefficiencies Reduce the performance impact of the reverse mapping btree when reflink is enabled by using the much faster non-overlapped btree lookup functions when we're searching the rmap index with a fully specified key. If we find the exact record we're looking for, great! We don't have to perform the full overlapped scan. For filesystems with high sharing factors this reduces the xfs_scrub runtime by a good 15%%. This has been shown to reduce the fstests runtime for realtime rmap configurations by 30%%, since the lack of AGs severely limits scalability. Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: validate v5 feature fieldsDave Chinner
We don't check that the v4 feature flags taht v5 requires to be set are actually set anywhere. Do this check when we see that the filesystem is a v5 filesystem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: set XFS_FEAT_NLINK correctlyDave Chinner
While xfs_has_nlink() is not used in kernel, it is used in userspace (e.g. by xfs_db) so we need to set the XFS_FEAT_NLINK flag correctly in xfs_sb_version_to_features(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: validate inode fork size against fork formatDave Chinner
xfs_repair catches fork size/format mismatches, but the in-kernel verifier doesn't, leading to null pointer failures when attempting to perform operations on the fork. This can occur in the xfs_dir_is_empty() where the in-memory fork format does not match the size and so the fork data pointer is accessed incorrectly. Note: this causes new failures in xfs/348 which is testing mode vs ftype mismatches. We now detect a regular file that has been changed to a directory or symlink mode as being corrupt because the data fork is for a symlink or directory should be in local form when there are only 3 bytes of data in the data fork. Hence the inode verify for the regular file now fires w/ -EFSCORRUPTED because the inode fork format does not match the format the corrupted mode says it should be in. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: detect self referencing btree sibling pointersDave Chinner
To catch the obvious graph cycle problem and hence potential endless looping. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: tag transactions that contain intent done itemsDave Chinner
Intent whiteouts will require extra work to be done during transaction commit if the transaction contains an intent done item. To determine if a transaction contains an intent done item, we want to avoid having to walk all the items in the transaction to check if they are intent done items. Hence when we add an intent done item to a transaction, tag the transaction to indicate that it contains such an item. We don't tag the transaction when the defer ops is relogging an intent to move it forward in the log. Whiteouts will never apply to these cases, so we don't need to bother looking for them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: don't commit the first deferred transaction without intentsDave Chinner
If the first operation in a string of defer ops has no intents, then there is no reason to commit it before running the first call to xfs_defer_finish_one(). This allows the defer ops to be used effectively for non-intent based operations without requiring an unnecessary extra transaction commit when first called. This fixes a regression in per-attribute modification transaction count when delayed attributes are not being used. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: hide log iovec alignment constraintsDave Chinner
Callers currently have to round out the size of buffers to match the aligment constraints of log iovecs and xlog_write(). They should not need to know this detail, so introduce a new function to calculate the iovec length (for use in ->iop_size implementations). Also modify xlog_finish_iovec() to round up the length to the correct alignment so the callers don't need to do this, either. Convert the only user - inode forks - of this alignment rounding to use the new interface. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04xfs: zero inode fork buffer at allocationDave Chinner
When we first allocate or resize an inline inode fork, we round up the allocation to 4 byte alingment to make journal alignment constraints. We don't clear the unused bytes, so we can copy up to three uninitialised bytes into the journal. Zero those bytes so we only ever copy zeros into the journal. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-28xfs: rename xfs_*alloc*_log_count to _block_countDarrick J. Wong
These functions return the maximum number of blocks that could be logged in a particular transaction. "log count" is confusing since there's a separate concept of a log (operation) count in the reservation code, so let's change it to "block count" to be less confusing. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: reduce transaction reservations with reflinkDarrick J. Wong
Before to the introduction of deferred refcount operations, reflink would try to cram refcount btree updates into the same transaction as an allocation or a free event. Mainline XFS has never actually done that, but we never refactored the transaction reservations to reflect that we now do all refcount updates in separate transactions. Fix this to reduce the transaction reservation size even farther, so that between this patch and the previous one, we reduce the tr_write and tr_itruncate sizes by 66%. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: reduce the absurdly large log operation countDarrick J. Wong
Back in the early days of reflink and rmap development I set the transaction reservation sizes to be overly generous for rmap+reflink filesystems, and a little under-generous for rmap-only filesystems. Since we don't need *eight* transaction rolls to handle three new log intent items, decrease the logcounts to what we actually need, and amend the shadow reservation computation function to reflect what we used to do so that the minimum log size doesn't change. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: report "max_resp" used for min log size computationDarrick J. Wong
Move the tracepoint that computes the size of the transaction used to compute the minimum log size into xfs_log_get_max_trans_res so that we only have to compute this stuff once. Leave xfs_log_get_max_trans_res as a non-static function so that xfs_db can call it to report the results of the userspace computation of the same value to diagnose mkfs/kernel misinteractions. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: create shadow transaction reservations for computing minimum log sizeDarrick J. Wong
Every time someone changes the transaction reservation sizes, they introduce potential compatibility problems if the changes affect the minimum log size that we validate at mount time. If the minimum log size gets larger (which should be avoided because doing so presents a serious risk of log livelock), filesystems created with old mkfs will not mount on a newer kernel; if the minimum size shrinks, filesystems created with newer mkfs will not mount on older kernels. Therefore, enable the creation of a shadow log reservation structure where we can "undo" the effects of tweaks when computing minimum log sizes. These shadow reservations should never be used in practice, but they insulate us from perturbations in minimum log size. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: stop artificially limiting the length of bunmap callsDarrick J. Wong
In commit e1a4e37cc7b6, we clamped the length of bunmapi calls on the data forks of shared files to avoid two failure scenarios: one where the extent being unmapped is so sparsely shared that we exceed the transaction reservation with the sheer number of refcount btree updates and EFI intent items; and the other where we attach so many deferred updates to the transaction that we pin the log tail and later the log head meets the tail, causing the log to livelock. We avoid triggering the first problem by tracking the number of ops in the refcount btree cursor and forcing a requeue of the refcount intent item any time we think that we might be close to overflowing. This has been baked into XFS since before the original e1a4 patch. A recent patchset fixed the second problem by changing the deferred ops code to finish all the work items created by each round of trying to complete a refcount intent item, which eliminates the long chains of deferred items (27dad); and causing long-running transactions to relog their intent log items when space in the log gets low (74f4d). Because this clamp affects /any/ unmapping request regardless of the sharing factors of the component blocks, it degrades the performance of all large unmapping requests -- whereas with an unshared file we can unmap millions of blocks in one go, shared files are limited to unmapping a few thousand blocks at a time, which causes the upper level code to spin in a bunmapi loop even if it wasn't needed. This also eliminates one more place where log recovery behavior can differ from online behavior, because bunmapi operations no longer need to requeue. The fstest generic/447 was created to test the old fix, and it still passes with this applied. Partial-revert-of: e1a4e37cc7b6 ("xfs: try to avoid blowing out the transaction reservation when bunmaping a shared extent") Depends: 27dada070d59 ("xfs: change the order in which child and parent defer ops ar finished") Depends: 74f4d6a1e065 ("xfs: only relog deferred intent items if free space in the log gets low") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-04-28xfs: count EFIs when deciding to ask for a continuation of a refcount updateDarrick J. Wong
A long time ago, I added to XFS the ability to use deferred reference count operations as part of a transaction chain. This enabled us to avoid blowing out the transaction reservation when the blocks in a physical extent all had different reference counts because we could ask the deferred operation manager for a continuation, which would get us a clean transaction. The refcount code asks for a continuation when the number of refcount record updates reaches the point where we think that the transaction has logged enough full btree blocks due to refcount (and free space) btree shape changes and refcount record updates that we're in danger of overflowing the transaction. We did not previously count the EFIs logged to the refcount update transaction because the clamps on the length of a bunmap operation were sufficient to avoid overflowing the transaction reservation even in the worst case situation where every other block of the unmapped extent is shared. Unfortunately, the restrictions on bunmap length avoid failure in the worst case by imposing a maximum unmap length of ~3000 blocks, even for non-pathological cases. This seriously limits performance when freeing large extents. Therefore, track EFIs with the same counter as refcount record updates, and use that information as input into when we should ask for a continuation. This enables the next patch to drop the clumsy bunmap limitation. Depends: 27dada070d59 ("xfs: change the order in which child and parent defer ops ar finished") Depends: 74f4d6a1e065 ("xfs: only relog deferred intent items if free space in the log gets low") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>