- May 12, 2022
-
-
Dave Chinner authored
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>
-
Dave Chinner authored
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:
Allison <Henderson<allison.henderson@oracle.com> Reviewed-by:
-
Dave Chinner authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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 authored
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:
-
- May 11, 2022
-
-
Dave Chinner authored
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 authored
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 authored
On the first allocation of a attrd item, xfs_trans_add_item() fires an assert like so: XFS (pmem0): EXPERIMENTAL logged extended attributes feature added. Use at your own risk! XFS: Assertion failed: !test_bit(XFS_LI_DIRTY, &lip->li_flags), file: fs/xfs/xfs_trans.c, line: 683 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! Call Trace: <TASK> xfs_trans_add_item+0x17e/0x190 xfs_trans_get_attrd+0x67/0x90 xfs_attr_create_done+0x13/0x20 xfs_defer_finish_noroll+0x100/0x690 __xfs_trans_commit+0x144/0x330 xfs_trans_commit+0x10/0x20 xfs_attr_set+0x3e2/0x4c0 xfs_initxattrs+0xaa/0xe0 security_inode_init_security+0xb0/0x130 xfs_init_security+0x18/0x20 xfs_generic_create+0x13a/0x340 xfs_vn_create+0x17/0x20 path_openat+0xff3/0x12f0 do_filp_open+0xb2/0x150 The attrd log item is allocated via kmem_cache_alloc, and xfs_log_item_init() does not zero the entire log item structure - it assumes that the structure is already all zeros as it only initialises non-zero fields. Fix the attr items to be allocated via the *zalloc methods. Signed-off-by:
-
Dave Chinner authored
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:
-
Allison Henderson authored
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:
Chandan Babu R <chandan.babu@oracle.com> Signed-off-by:
-
Allison Henderson authored
Add an error tag on xfs_da3_split to test log attribute recovery and replay. Signed-off-by:
-
Allison Henderson authored
Quick helper function to collapse duplicate code to initialize transactions for attributes Signed-off-by:
-
Allison Henderson authored
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:
Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by:
-
Allison Henderson authored
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:
Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by:
-
Allison Henderson authored
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 authored
This patch adds an error tag that we can use to test log attribute recovery and replay Signed-off-by:
-
Allison Henderson authored
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 authored
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:
-
- May 09, 2022
-
-
Allison Henderson authored
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 authored
This patch adds the needed routines to create, log and recover logged extended attribute intents. Signed-off-by:
-
- May 04, 2022
-
-
Allison Henderson authored
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 authored
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 authored
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:
-
Dave Chinner authored
-
Dave Chinner authored
Merge tag 'reflink-speedups-5.19_2022-04-28' of 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 authored
Merge tag 'rmap-speedups-5.19_2022-04-28' of 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 authored
-
Dave Chinner authored
-
Dave Chinner authored
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:
Christoph Hellwig <hch@lst.de> Reviewed-by:
-
Dave Chinner authored
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 authored
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 authored
To catch the obvious graph cycle problem and hence potential endless looping. Signed-off-by:
-
Dave Chinner authored
When we log modifications based on intents, we add both intent and intent done items to the modification being made. These get written to the log to ensure that the operation is re-run if the intent done is not found in the log. However, for operations that complete wholly within a single checkpoint, the change in the checkpoint is atomic and will never need replay. In this case, we don't need to actually write the intent and intent done items to the journal because log recovery will never need to manually restart this modification. Log recovery currently handles intent/intent done matching by inserting the intent into the AIL, then removing it when a matching intent done item is found. Hence for all the intent-based operations that complete within a checkpoint, we spend all that time parsing the intent/intent done items just to cancel them and do nothing with them. Hence it follows that the only time we actually need intents in the log is when the modification crosses checkpoint boundaries in the log and so may only be partially complete in the journal. Hence if we commit and intent done item to the CIL and the intent item is in the same checkpoint, we don't actually have to write them to the journal because log recovery will always cancel the intents. We've never really worried about the overhead of logging intents unnecessarily like this because the intents we log are generally very much smaller than the change being made. e.g. freeing an extent involves modifying at lease two freespace btree blocks and the AGF, so the EFI/EFD overhead is only a small increase in space and processing time compared to the overall cost of freeing an extent. However, delayed attributes change this cost equation dramatically, especially for inline attributes. In the case of adding an inline attribute, we only log the inode core and attribute fork at present. With delayed attributes, we now log the attr intent which includes the name and value, the inode core adn attr fork, and finally the attr intent done item. We increase the number of items we log from 1 to 3, and the number of log vectors (regions) goes up from 3 to 7. Hence we tripple the number of objects that the CIL has to process, and more than double the number of log vectors that need to be written to the journal. At scale, this means delayed attributes cause a non-pipelined CIL to become CPU bound processing all the extra items, resulting in a > 40% performance degradation on 16-way file+xattr create worklaods. Pipelining the CIL (as per 5.15) reduces the performance degradation to 20%, but now the limitation is the rate at which the log items can be written to the iclogs and iclogs be dispatched for IO and completed. Even log IO completion is slowed down by these intents, because it now has to process 3x the number of items in the checkpoint. Processing completed intents is especially inefficient here, because we first insert the intent into the AIL, then remove it from the AIL when the intent done is processed. IOWs, we are also doing expensive operations in log IO completion we could completely avoid if we didn't log completed intent/intent done pairs. Enter log item whiteouts. When an intent done is committed, we can check to see if the associated intent is in the same checkpoint as we are currently committing the intent done to. If so, we can mark the intent log item with a whiteout and immediately free the intent done item rather than committing it to the CIL. We can basically skip the entire formatting and CIL insertion steps for the intent done item. However, we cannot remove the intent item from the CIL at this point because the unlocked per-cpu CIL item lists do not permit removal without holding the CIL context lock exclusively. Transaction commit only holds the context lock shared, hence the best we can do is mark the intent item with a whiteout so that the CIL push can release it rather than writing it to the log. This means we never write the intent to the log if the intent done has also been committed to the same checkpoint, but we'll always write the intent if the intent done has not been committed or has been committed to a different checkpoint. This will result in correct log recovery behaviour in all cases, without the overhead of logging unnecessary intents. This intent whiteout concept is generic - we can apply it to all intent/intent done pairs that have a direct 1:1 relationship. The way deferred ops iterate and relog intents mean that all intents currently have a 1:1 relationship with their done intent, and hence we can apply this cancellation to all existing intent/intent done implementations. For delayed attributes with a 16-way 64kB xattr create workload, whiteouts reduce the amount of journalled metadata from ~2.5GB/s down to ~600MB/s and improve the creation rate from 9000/s to 14000/s. Signed-off-by:
-
