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082fd1ea |
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16-Jan-2024 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: optimize the case of no parent watcher If parent inode is not watching, check for the event in masks of sb/mount/inode masks early to optimize out most of the code in __fsnotify_parent() and avoid calling fsnotify(). Jens has reported that this optimization improves BW and IOPS in an io_uring benchmark by more than 10% and reduces perf reported CPU usage. before: + 4.51% io_uring [kernel.vmlinux] [k] fsnotify + 3.67% io_uring [kernel.vmlinux] [k] __fsnotify_parent after: + 2.37% io_uring [kernel.vmlinux] [k] __fsnotify_parent Reported-and-tested-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/linux-fsdevel/b45bd8ff-5654-4e67-90a6-aad5e6759e0b@kernel.dk/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20240116113247.758848-1-amir73il@gmail.com>
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da549bdd |
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07-Nov-2023 |
Al Viro <viro@zeniv.linux.org.uk> |
dentry: switch the lists of children to hlist Saves a pointer per struct dentry and actually makes the things less clumsy. Cleaned the d_walk() and dcache_readdir() a bit by use of hlist_for_... iterators. A couple of new helpers - d_first_child() and d_next_sibling(), to make the expressions less awful. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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feee1ce4 |
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22-Jul-2022 |
Xin Gao <gaoxin@cdjrlc.com> |
fsnotify: Fix comment typo The double `if' is duplicated in line 104, remove one. Signed-off-by: Xin Gao <gaoxin@cdjrlc.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220722194639.18545-1-gaoxin@cdjrlc.com
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31a371e4 |
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29-Jun-2022 |
Amir Goldstein <amir73il@gmail.com> |
fanotify: prepare for setting event flags in ignore mask Setting flags FAN_ONDIR FAN_EVENT_ON_CHILD in ignore mask has no effect. The FAN_EVENT_ON_CHILD flag in mask implicitly applies to ignore mask and ignore mask is always implicitly applied to events on directories. Define a mark flag that replaces this legacy behavior with logic of applying the ignore mask according to event flags in ignore mask. Implement the new logic to prepare for supporting an ignore mask that ignores events on children and ignore mask that does not ignore events on directories. To emphasize the change in terminology, also rename ignored_mask mark member to ignore_mask and use accessors to get only the effective ignored events or the ignored events and flags. This change in terminology finally aligns with the "ignore mask" language in man pages and in most of the comments. Link: https://lore.kernel.org/r/20220629144210.2983229-2-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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e730558a |
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11-May-2022 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: consistent behavior for parent not watching children The logic for handling events on child in groups that have a mark on the parent inode, but without FS_EVENT_ON_CHILD flag in the mask is duplicated in several places and inconsistent. Move the logic into the preparation of mark type iterator, so that the parent mark type will be excluded from all mark type iterations in that case. This results in several subtle changes of behavior, hopefully all desired changes of behavior, for example: - Group A has a mount mark with FS_MODIFY in mask - Group A has a mark with ignore mask that does not survive FS_MODIFY and does not watch children on directory D. - Group B has a mark with FS_MODIFY in mask that does watch children on directory D. - FS_MODIFY event on file D/foo should not clear the ignore mask of group A, but before this change it does And if group A ignore mask was set to survive FS_MODIFY: - FS_MODIFY event on file D/foo should be reported to group A on account of the mount mark, but before this change it is wrongly ignored Fixes: 2f02fd3fa13e ("fanotify: fix ignore mask logic for events on child and on dir") Reported-by: Jan Kara <jack@suse.com> Link: https://lore.kernel.org/linux-fsdevel/20220314113337.j7slrb5srxukztje@quack3.lan/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220511190213.831646-3-amir73il@gmail.com
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14362a25 |
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11-May-2022 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: introduce mark type iterator fsnotify_foreach_iter_mark_type() is used to reduce boilerplate code of iterating all marks of a specific group interested in an event by consulting the iterator report_mask. Use an open coded version of that iterator in fsnotify_iter_next() that collects all marks of the current iteration group without consulting the iterator report_mask. At the moment, the two iterator variants are the same, but this decoupling will allow us to exclude some of the group's marks from reporting the event, for example for event on child and inode marks on parent did not request to watch events on children. Fixes: 2f02fd3fa13e ("fanotify: fix ignore mask logic for events on child and on dir") Reported-by: Jan Kara <jack@suse.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220511190213.831646-2-amir73il@gmail.com
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38035c04 |
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22-Apr-2022 |
Amir Goldstein <amir73il@gmail.com> |
inotify: move control flags from mask to mark flags The inotify control flags in the mark mask (e.g. FS_IN_ONE_SHOT) are not relevant to object interest mask, so move them to the mark flags. This frees up some bits in the object interest mask. Link: https://lore.kernel.org/r/20220422120327.3459282-3-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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f92ca72b |
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11-Mar-2022 |
Bang Li <libang.linuxer@gmail.com> |
fsnotify: remove redundant parameter judgment iput() has already judged the incoming parameter, so there is no need to repeat the judgment here. Link: https://lore.kernel.org/r/20220311151240.62045-1-libang.linuxer@gmail.com Signed-off-by: Bang Li <libang.linuxer@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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04e317ba |
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23-Feb-2022 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: optimize FS_MODIFY events with no ignored masks fsnotify() treats FS_MODIFY events specially - it does not skip them even if the FS_MODIFY event does not apear in the object's fsnotify mask. This is because send_to_group() checks if FS_MODIFY needs to clear ignored mask of marks. The common case is that an object does not have any mark with ignored mask and in particular, that it does not have a mark with ignored mask and without the FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY flag. Set FS_MODIFY in object's fsnotify mask during fsnotify_recalc_mask() if object has a mark with an ignored mask and without the FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY flag and remove the special treatment of FS_MODIFY in fsnotify(), so that FS_MODIFY events could be optimized in the common case. Call fsnotify_recalc_mask() from fanotify after adding or removing an ignored mask from a mark without FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY or when adding the FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY flag to a mark with ignored mask (the flag cannot be removed by fanotify uapi). Performance results for doing 10000000 write(2)s to tmpfs: vanilla patched without notification mark 25.486+-1.054 24.965+-0.244 with notification mark 30.111+-0.139 26.891+-1.355 So we can see the overhead of notification subsystem has been drastically reduced. Link: https://lore.kernel.org/r/20220223151438.790268-3-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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e54183fa |
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29-Nov-2021 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: generate FS_RENAME event with rich information The dnotify FS_DN_RENAME event is used to request notification about a move within the same parent directory and was always coupled with the FS_MOVED_FROM event. Rename the FS_DN_RENAME event flag to FS_RENAME, decouple it from FS_MOVED_FROM and report it with the moved dentry instead of the moved inode, so it has the information about both old and new parent and name. Generate the FS_RENAME event regardless of same parent dir and apply the "same parent" rule in the generic fsnotify_handle_event() helper that is used to call backends with ->handle_inode_event() method (i.e. dnotify). The ->handle_inode_event() method is not rich enough to report both old and new parent and name anyway. The enriched event is reported to fanotify over the ->handle_event() method with the old and new dir inode marks in marks array slots for ITER_TYPE_INODE and a new iter type slot ITER_TYPE_INODE2. The enriched event will be used for reporting old and new parent+name to fanotify groups with FAN_RENAME events. Link: https://lore.kernel.org/r/20211129201537.1932819-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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1c9007d6 |
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29-Nov-2021 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: separate mark iterator type from object type enum They are two different types that use the same enum, so this confusing. Use the object type to indicate the type of object mark is attached to and the iter type to indicate the type of watch. A group can have two different watches of the same object type (parent and child watches) that match the same event. Link: https://lore.kernel.org/r/20211129201537.1932819-3-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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24dca905 |
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25-Oct-2021 |
Gabriel Krisman Bertazi <krisman@collabora.com> |
fsnotify: Protect fsnotify_handle_inode_event from no-inode events FAN_FS_ERROR allows events without inodes - i.e. for file system-wide errors. Even though fsnotify_handle_inode_event is not currently used by fanotify, this patch protects other backends from cases where neither inode or dir are provided. Also document the constraints of the interface (inode and dir cannot be both NULL). Link: https://lore.kernel.org/r/20211025192746.66445-12-krisman@collabora.com Suggested-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jan Kara <jack@suse.cz>
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29335033 |
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25-Oct-2021 |
Gabriel Krisman Bertazi <krisman@collabora.com> |
fsnotify: Retrieve super block from the data field Some file system events (i.e. FS_ERROR) might not be associated with an inode or directory. For these, we can retrieve the super block from the data field. But, since the super_block is available in the data field on every event type, simplify the code to always retrieve it from there, through a new helper. Link: https://lore.kernel.org/r/20211025192746.66445-11-krisman@collabora.com Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
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ec44610f |
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10-Aug-2021 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: count all objects with attached connectors Rename s_fsnotify_inode_refs to s_fsnotify_connectors and count all objects with attached connectors, not only inodes with attached connectors. This will be used to optimize fsnotify() calls on sb without any type of marks. Link: https://lore.kernel.org/r/20210810151220.285179-4-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Matthew Bobrowski <repnop@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
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fecc4559 |
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02-Dec-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: fix events reported to watching parent and child fsnotify_parent() used to send two separate events to backends when a parent inode is watching children and the child inode is also watching. In an attempt to avoid duplicate events in fanotify, we unified the two backend callbacks to a single callback and handled the reporting of the two separate events for the relevant backends (inotify and dnotify). However the handling is buggy and can result in inotify and dnotify listeners receiving events of the type they never asked for or spurious events. The problem is the unified event callback with two inode marks (parent and child) is called when any of the parent and child inodes are watched and interested in the event, but the parent inode's mark that is interested in the event on the child is not necessarily the one we are currently reporting to (it could belong to a different group). So before reporting the parent or child event flavor to backend we need to check that the mark is really interested in that event flavor. The semantics of INODE and CHILD marks were hard to follow and made the logic more complicated than it should have been. Replace it with INODE and PARENT marks semantics to hopefully make the logic more clear. Thanks to Hugh Dickins for spotting a bug in the earlier version of this patch. Fixes: 497b0c5a7c06 ("fsnotify: send event to parent and child with single callback") CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201202120713.702387-4-amir73il@gmail.com Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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950cc0d2 |
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02-Dec-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: generalize handle_inode_event() The handle_inode_event() interface was added as (quoting comment): "a simple variant of handle_event() for groups that only have inode marks and don't have ignore mask". In other words, all backends except fanotify. The inotify backend also falls under this category, but because it required extra arguments it was left out of the initial pass of backends conversion to the simple interface. This results in code duplication between the generic helper fsnotify_handle_event() and the inotify_handle_event() callback which also happen to be buggy code. Generalize the handle_inode_event() arguments and add the check for FS_EXCL_UNLINK flag to the generic helper, so inotify backend could be converted to use the simple interface. Link: https://lore.kernel.org/r/20201202120713.702387-2-amir73il@gmail.com CC: stable@vger.kernel.org Fixes: b9a1b9772509 ("fsnotify: create method handle_inode_event() in fsnotify_operations") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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7372e79c |
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07-Nov-2020 |
Amir Goldstein <amir73il@gmail.com> |
fanotify: fix logic of reporting name info with watched parent The victim inode's parent and name info is required when an event needs to be delivered to a group interested in filename info OR when the inode's parent is interested in an event on its children. Let us call the first condition 'parent_needed' and the second condition 'parent_interested'. In fsnotify_parent(), the condition where the inode's parent is interested in some events on its children, but not necessarily interested the specific event is called 'parent_watched'. fsnotify_parent() tests the condition (!parent_watched && !parent_needed) for sending the event without parent and name info, which is correct. It then wrongly assumes that parent_watched implies !parent_needed and tests the condition (parent_watched && !parent_interested) for sending the event without parent and name info, which is wrong, because parent may still be needed by some group. For example, after initializing a group with FAN_REPORT_DFID_NAME and adding a FAN_MARK_MOUNT with FAN_OPEN mask, open events on non-directory children of "testdir" are delivered with file name info. After adding another mark to the same group on the parent "testdir" with FAN_CLOSE|FAN_EVENT_ON_CHILD mask, open events on non-directory children of "testdir" are no longer delivered with file name info. Fix the logic and use auxiliary variables to clarify the conditions. Fixes: 9b93f33105f5 ("fsnotify: send event with parent/name info to sb/mount/non-dir marks") Cc: stable@vger.kernel.org#v5.9 Link: https://lore.kernel.org/r/20201108105906.8493-1-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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b9a1b977 |
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22-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: create method handle_inode_event() in fsnotify_operations The method handle_event() grew a lot of complexity due to the design of fanotify and merging of ignore masks. Most backends do not care about this complex functionality, so we can hide this complexity from them. Introduce a method handle_inode_event() that serves those backends and passes a single inode mark and less arguments. This change converts all backends except fanotify and inotify to use the simplified handle_inode_event() method. In pricipal, inotify could have also used the new method, but that would require passing more arguments on the simple helper (data, data_type, cookie), so we leave it with the handle_event() method. Link: https://lore.kernel.org/r/20200722125849.17418-9-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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9b93f331 |
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16-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: send event with parent/name info to sb/mount/non-dir marks Similar to events "on child" to watching directory, send event with parent/name info if sb/mount/non-dir marks are interested in parent/name info. The FS_EVENT_ON_CHILD flag can be set on sb/mount/non-dir marks to specify interest in parent/name info for events on non-directory inodes. Events on "orphan" children (disconnected dentries) are sent without parent/name info. Events on directories are sent with parent/name info only if the parent directory is watching. After this change, even groups that do not subscribe to events on children could get an event with mark iterator type TYPE_CHILD and without mark iterator type TYPE_INODE if fanotify has marks on the same objects. dnotify and inotify event handlers can already cope with that situation. audit does not subscribe to events that are possible on child, so won't get to this situation. nfsd does not access the marks iterator from its event handler at the moment, so it is not affected. This is a bit too fragile, so we should prepare all groups to cope with mark type TYPE_CHILD preferably using a generic helper. Link: https://lore.kernel.org/r/20200716084230.30611-16-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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40a100d3 |
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22-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: pass dir and inode arguments to fsnotify() The arguments of fsnotify() are overloaded and mean different things for different event types. Replace the to_tell argument with separate arguments @dir and @inode, because we may be sending to both dir and child. Using the @data argument to pass the child is not enough, because dirent events pass this argument (for audit), but we do not report to child. Document the new fsnotify() function argumenets. Link: https://lore.kernel.org/r/20200722125849.17418-7-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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82ace1ef |
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22-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: create helper fsnotify_inode() Simple helper to consolidate biolerplate code. Link: https://lore.kernel.org/r/20200722125849.17418-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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497b0c5a |
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16-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: send event to parent and child with single callback Instead of calling fsnotify() twice, once with parent inode and once with child inode, if event should be sent to parent inode, send it with both parent and child inodes marks in object type iterator and call the backend handle_event() callback only once. The parent inode is assigned to the standard "inode" iterator type and the child inode is assigned to the special "child" iterator type. In that case, the bit FS_EVENT_ON_CHILD will be set in the event mask, the dir argument to handle_event will be the parent inode, the file_name argument to handle_event is non NULL and refers to the name of the child and the child inode can be accessed with fsnotify_data_inode(). This will allow fanotify to make decisions based on child or parent's ignored mask. For example, when a parent is interested in a specific event on its children, but a specific child wishes to ignore this event, the event will not be reported. This is not what happens with current code, but according to man page, it is the expected behavior. Link: https://lore.kernel.org/r/20200716084230.30611-15-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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08b95c33 |
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08-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fanotify: remove event FAN_DIR_MODIFY It was never enabled in uapi and its functionality is about to be superseded by events FAN_CREATE, FAN_DELETE, FAN_MOVE with group flag FAN_REPORT_NAME. Keep a place holder variable name_event instead of removing the name recording code since it will be used by the new events. Link: https://lore.kernel.org/r/20200708111156.24659-17-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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b54cecf5 |
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06-Jun-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: pass dir argument to handle_event() callback The 'inode' argument to handle_event(), sometimes referred to as 'to_tell' is somewhat obsolete. It is a remnant from the times when a group could only have an inode mark associated with an event. We now pass an iter_info array to the callback, with all marks associated with an event. Most backends ignore this argument, with two exceptions: 1. dnotify uses it for sanity check that event is on directory 2. fanotify uses it to report fid of directory on directory entry modification events Remove the 'inode' argument and add a 'dir' argument. The callback function signature is deliberately changed, because the meaning of the argument has changed and the arguments have been documented. The 'dir' argument is set to when 'file_name' is specified and it is referring to the directory that the 'file_name' entry belongs to. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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c738fbab |
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08-Jul-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: fold fsnotify() call into fsnotify_parent() All (two) callers of fsnotify_parent() also call fsnotify() to notify the child inode. Move the second fsnotify() call into fsnotify_parent(). This will allow more flexibility in making decisions about which of the two event falvors should be sent. Using 'goto notify_child' in the inline helper seems a bit strange, but it mimics the code in __fsnotify_parent() for clarity and the goto pattern will become less strage after following patches are applied. Link: https://lore.kernel.org/r/20200708111156.24659-2-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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71d73410 |
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08-Jul-2020 |
Mel Gorman <mgorman@techsingularity.net> |
fsnotify: Rearrange fast path to minimise overhead when there is no watcher The fsnotify paths are trivial to hit even when there are no watchers and they are surprisingly expensive. For example, every successful vfs_write() hits fsnotify_modify which calls both fsnotify_parent and fsnotify unless FMODE_NONOTIFY is set which is an internal flag invisible to userspace. As it stands, fsnotify_parent is a guaranteed functional call even if there are no watchers and fsnotify() does a substantial amount of unnecessary work before it checks if there are any watchers. A perf profile showed that applying mnt->mnt_fsnotify_mask in fnotify() was almost half of the total samples taken in that function during a test. This patch rearranges the fast paths to reduce the amount of work done when there are no watchers. The test motivating this was "perf bench sched messaging --pipe". Despite the fact the pipes are anonymous, fsnotify is still called a lot and the overhead is noticeable even though it's completely pointless. It's likely the overhead is negligible for real IO so this is an extreme example. This is a comparison of hackbench using processes and pipes on a 1-socket machine with 8 CPU threads without fanotify watchers. 5.7.0 5.7.0 vanilla fastfsnotify-v1r1 Amean 1 0.4837 ( 0.00%) 0.4630 * 4.27%* Amean 3 1.5447 ( 0.00%) 1.4557 ( 5.76%) Amean 5 2.6037 ( 0.00%) 2.4363 ( 6.43%) Amean 7 3.5987 ( 0.00%) 3.4757 ( 3.42%) Amean 12 5.8267 ( 0.00%) 5.6983 ( 2.20%) Amean 18 8.4400 ( 0.00%) 8.1327 ( 3.64%) Amean 24 11.0187 ( 0.00%) 10.0290 * 8.98%* Amean 30 13.1013 ( 0.00%) 12.8510 ( 1.91%) Amean 32 13.9190 ( 0.00%) 13.2410 ( 4.87%) 5.7.0 5.7.0 vanilla fastfsnotify-v1r1 Duration User 157.05 152.79 Duration System 1279.98 1219.32 Duration Elapsed 182.81 174.52 This is showing that the latencies are improved by roughly 2-9%. The variability is not shown but some of these results are within the noise as this workload heavily overloads the machine. That said, the system CPU usage is reduced by quite a bit so it makes sense to avoid the overhead even if it is a bit tricky to detect at times. A perf profile of just 1 group of tasks showed that 5.14% of samples taken were in either fsnotify() or fsnotify_parent(). With the patch, 2.8% of samples were in fsnotify, mostly function entry and the initial check for watchers. The check for watchers is complicated enough that inlining it may be controversial. [Amir] Slightly simplify with mnt_or_sb_mask => marks_mask Link: https://lore.kernel.org/r/20200708111156.24659-1-amir73il@gmail.com Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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9e2ba2c3 |
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19-Mar-2020 |
Amir Goldstein <amir73il@gmail.com> |
fanotify: send FAN_DIR_MODIFY event flavor with dir inode and name Dirent events are going to be supported in two flavors: 1. Directory fid info + mask that includes the specific event types (e.g. FAN_CREATE) and an optional FAN_ONDIR flag. 2. Directory fid info + name + mask that includes only FAN_DIR_MODIFY. To request the second event flavor, user needs to set the event type FAN_DIR_MODIFY in the mark mask. The first flavor is supported since kernel v5.1 for groups initialized with flag FAN_REPORT_FID. It is intended to be used for watching directories in "batch mode" - the watcher is notified when directory is changed and re-scans the directory content in response. This event flavor is stored more compactly in the event queue, so it is optimal for workloads with frequent directory changes. The second event flavor is intended to be used for watching large directories, where the cost of re-scan of the directory on every change is considered too high. The watcher getting the event with the directory fid and entry name is expected to call fstatat(2) to query the content of the entry after the change. Legacy inotify events are reported with name and event mask (e.g. "foo", FAN_CREATE | FAN_ONDIR). That can lead users to the conclusion that there is *currently* an entry "foo" that is a sub-directory, when in fact "foo" may be negative or non-dir by the time user gets the event. To make it clear that the current state of the named entry is unknown, when reporting an event with name info, fanotify obfuscates the specific event types (e.g. create,delete,rename) and uses a common event type - FAN_DIR_MODIFY to describe the change. This should make it harder for users to make wrong assumptions and write buggy filesystem monitors. At this point, name info reporting is not yet implemented, so trying to set FAN_DIR_MODIFY in mark mask will return -EINVAL. Link: https://lore.kernel.org/r/20200319151022.31456-12-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
017de65f |
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19-Mar-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: simplify arguments passing to fsnotify_parent() Instead of passing both dentry and path and having to figure out which one to use, pass data/data_type to simplify the code. Link: https://lore.kernel.org/r/20200319151022.31456-6-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
aa93bdc5 |
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19-Mar-2020 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: use helpers to access data by data_type Create helpers to access path and inode from different data types. Link: https://lore.kernel.org/r/20200319151022.31456-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
1edc8eb2 |
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06-Dec-2019 |
Eric Sandeen <sandeen@redhat.com> |
fs: call fsnotify_sb_delete after evict_inodes When a filesystem is unmounted, we currently call fsnotify_sb_delete() before evict_inodes(), which means that fsnotify_unmount_inodes() must iterate over all inodes on the superblock looking for any inodes with watches. This is inefficient and can lead to livelocks as it iterates over many unwatched inodes. At this point, SB_ACTIVE is gone and dropping refcount to zero kicks the inode out out immediately, so anything processed by fsnotify_sb_delete / fsnotify_unmount_inodes gets evicted in that loop. After that, the call to evict_inodes will evict everything else with a zero refcount. This should speed things up overall, and avoid livelocks in fsnotify_unmount_inodes(). Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
04646aeb |
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06-Dec-2019 |
Eric Sandeen <sandeen@redhat.com> |
fs: avoid softlockups in s_inodes iterators Anything that walks all inodes on sb->s_inodes list without rescheduling risks softlockups. Previous efforts were made in 2 functions, see: c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb() ac05fbb inode: don't softlockup when evicting inodes but there hasn't been an audit of all walkers, so do that now. This also consistently moves the cond_resched() calls to the bottom of each loop in cases where it already exists. One loop remains: remove_dquot_ref(), because I'm not quite sure how to deal with that one w/o taking the i_lock. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
4a0b20be |
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15-Oct-2019 |
Ben Dooks <ben.dooks@codethink.co.uk> |
fsnotify: move declaration of fsnotify_mark_connector_cachep to fsnotify.h Move fsnotify_mark_connector_cachep to fsnotify.h to properly share it with the user in mark.c and avoid the following warning from sparse: fs/notify/mark.c:82:19: warning: symbol 'fsnotify_mark_connector_cachep' was not declared. Should it be static? Link: https://lore.kernel.org/r/20191015132518.21819-1-ben.dooks@codethink.co.uk Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Jan Kara <jack@suse.cz>
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#
7377f5be |
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26-May-2019 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: get rid of fsnotify_nameremove() For all callers of fsnotify_{unlink,rmdir}(), we made sure that d_parent and d_name are stable. Therefore, fsnotify_{unlink,rmdir}() do not need the safety measures in fsnotify_nameremove() to stabilize parent and name. We can now simplify those hooks and get rid of fsnotify_nameremove(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
c82ee6d3 |
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19-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18 Based on 1 normalized pattern(s): 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 either version 2 or at your option any later version this program is distributed in the hope that it will 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 see the file copying if not write to the free software foundation 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 52 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154042.342335923@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4d8e7055 |
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04-May-2019 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: fix unlink performance regression __fsnotify_parent() has an optimization in place to avoid unneeded take_dentry_name_snapshot(). When fsnotify_nameremove() was changed not to call __fsnotify_parent(), we left out the optimization. Kernel test robot reported a 5% performance regression in concurrent unlink() workload. Reported-by: kernel test robot <rong.a.chen@intel.com> Link: https://lore.kernel.org/lkml/20190505062153.GG29809@shao2-debian/ Link: https://lore.kernel.org/linux-fsdevel/20190104090357.GD22409@quack2.suse.cz/ Fixes: 5f02a8776384 ("fsnotify: annotate directory entry modification events") CC: stable@vger.kernel.org Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
e43e9c33 |
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26-Apr-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
fsnotify: switch send_to_group() and ->handle_event to const struct qstr * note that conditions surrounding accesses to dname in audit_watch_handle_event() and audit_mark_handle_event() guarantee that dname won't have been NULL. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
25b229df |
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26-Apr-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
fsnotify(): switch to passing const struct qstr * for file_name Note that in fnsotify_move() and fsnotify_link() we are guaranteed that dentry->d_name won't change during the fsnotify() evaluation (by having the parent directory locked exclusive), so we don't need to fetch dentry->d_name.name in the callers. In fsnotify_dirent() the same stability of dentry->d_name is also true, but it's a bit more convoluted - there is one callchain (devpts_pty_new() -> fsnotify_create() -> fsnotify_dirent()) where the parent is _not_ locked, but on devpts ->d_name of everything is unchanging; it has neither explicit nor implicit renames. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
230c6402 |
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26-Apr-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
ovl_lookup_real_one(): don't bother with strlen() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
45a9fb37 |
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10-Jan-2019 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: send all event types to super block marks So far, existence of super block marks was checked only on events with data type FSNOTIFY_EVENT_PATH. Use the super block of the "to_tell" inode to report the events of all event types to super block marks. This change has no effect on current backends. Soon, this will allow fanotify backend to receive all event types on a super block mark. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
66917a31 |
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07-Nov-2018 |
Matthew Bobrowski <mbobrowski@mbobrowski.org> |
fanotify: introduce new event mask FAN_OPEN_EXEC_PERM A new event mask FAN_OPEN_EXEC_PERM has been defined. This allows users to receive events and grant access to files that are intending to be opened for execution. Events of FAN_OPEN_EXEC_PERM type will be generated when a file has been opened by using either execve(), execveat() or uselib() system calls. This acts in the same manner as previous permission event mask, meaning that an access response is required from the user application in order to permit any further operations on the file. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
9b076f1c |
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07-Nov-2018 |
Matthew Bobrowski <mbobrowski@mbobrowski.org> |
fanotify: introduce new event mask FAN_OPEN_EXEC A new event mask FAN_OPEN_EXEC has been defined so that users have the ability to receive events specifically when a file has been opened with the intent to be executed. Events of FAN_OPEN_EXEC type will be generated when a file has been opened using either execve(), execveat() or uselib() system calls. The feature is implemented within fsnotify_open() by generating the FAN_OPEN_EXEC event type if __FMODE_EXEC is set within file->f_flags. Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
b469e7e4 |
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30-Oct-2018 |
Amir Goldstein <amir73il@gmail.com> |
fanotify: fix handling of events on child sub-directory When an event is reported on a sub-directory and the parent inode has a mark mask with FS_EVENT_ON_CHILD|FS_ISDIR, the event will be sent to fsnotify() even if the event type is not in the parent mark mask (e.g. FS_OPEN). Further more, if that event happened on a mount or a filesystem with a mount/sb mark that does have that event type in their mask, the "on child" event will be reported on the mount/sb mark. That is not desired, because user will get a duplicate event for the same action. Note that the event reported on the victim inode is never merged with the event reported on the parent inode, because of the check in should_merge(): old_fsn->inode == new_fsn->inode. Fix this by looking for a match of an actual event type (i.e. not just FS_ISDIR) in parent's inode mark mask and by not reporting an "on child" event to group if event type is only found on mount/sb marks. [backport hint: The bug seems to have always been in fanotify, but this patch will only apply cleanly to v4.19.y] Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
721fb6fb |
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17-Oct-2018 |
Jan Kara <jack@suse.cz> |
fsnotify: Fix busy inodes during unmount Detaching of mark connector from fsnotify_put_mark() can race with unmounting of the filesystem like: CPU1 CPU2 fsnotify_put_mark() spin_lock(&conn->lock); ... inode = fsnotify_detach_connector_from_object(conn) spin_unlock(&conn->lock); generic_shutdown_super() fsnotify_unmount_inodes() sees connector detached for inode -> nothing to do evict_inode() barfs on pending inode reference iput(inode); Resulting in "Busy inodes after unmount" message and possible kernel oops. Make fsnotify_unmount_inodes() properly wait for outstanding inode references from detached connectors. Note that the accounting of outstanding inode references in the superblock can cause some cacheline contention on the counter. OTOH it happens only during deletion of the last notification mark from an inode (or during unlinking of watched inode) and that is not too bad. I have measured time to create & delete inotify watch 100000 times from 64 processes in parallel (each process having its own inotify group and its own file on a shared superblock) on a 64 CPU machine. Average and standard deviation of 15 runs look like: Avg Stddev Vanilla 9.817400 0.276165 Fixed 9.710467 0.228294 So there's no statistically significant difference. Fixes: 6b3f05d24d35 ("fsnotify: Detach mark from object list when last reference is dropped") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz>
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#
a39f7ec4 |
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03-Oct-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: convert runtime BUG_ON() to BUILD_BUG_ON() The BUG_ON() statements to verify number of bits in ALL_FSNOTIFY_BITS and ALL_INOTIFY_BITS are converted to build time check of the constant. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
007d1e83 |
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03-Oct-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: generalize handling of extra event flags FS_EVENT_ON_CHILD gets a special treatment in fsnotify() because it is not a flag specifying an event type, but rather an extra flags that may be reported along with another event and control the handling of the event by the backend. FS_ISDIR is also an "extra flag" and not an "event type" and therefore desrves the same treatment. With inotify/dnotify backends it was never possible to set FS_ISDIR in mark masks, so it did not matter. With fanotify backend, mark adding code jumps through hoops to avoid setting the FS_ISDIR in the commulative object mask. Separate the constant ALL_FSNOTIFY_EVENTS to ALL_FSNOTIFY_FLAGS and ALL_FSNOTIFY_EVENTS, so the latter can be used to test for specific event types. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
60f7ed8c |
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01-Sep-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: send path type events to group with super block marks Send events to group if super block mark mask matches the event and unless the same group has an ignore mask on the vfsmount or the inode on which the event occurred. Soon, fanotify backend is going to support super block marks and fanotify backend only supports path type events. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
1e6cb723 |
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01-Sep-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: add super block object type Add the infrastructure to attach a mark to a super_block struct and detach all attached marks when super block is destroyed. This is going to be used by fanotify backend to setup super block marks. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
9bdda4e9 |
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01-Sep-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: fix ignore mask logic in fsnotify() Commit 92183a42898d ("fsnotify: fix ignore mask logic in send_to_group()") acknoledges the use case of ignoring an event on an inode mark, because of an ignore mask on a mount mark of the same group (i.e. I want to get all events on this file, except for the events that came from that mount). This change depends on correctly merging the inode marks and mount marks group lists, so that the mount mark ignore mask would be tested in send_to_group(). Alas, the merging of the lists did not take into account the case where event in question is not in the mask of any of the mount marks. To fix this, completely remove the tests for inode and mount event masks from the lists merging code. Fixes: 92183a42898d ("fsnotify: fix ignore mask logic in send_to_group") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
3dca1a74 |
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20-Apr-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: generalize send_to_group() Use fsnotify_foreach_obj_type macros to generalize the code that filters events by marks mask and ignored_mask. This is going to be used for adding mark of super block object type. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
47d9c7cc |
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20-Apr-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: generalize iteration of marks by object type Make some code that handles marks of object types inode and vfsmount generic, so it can handle other object types. Introduce fsnotify_foreach_obj_type macro to iterate marks by object type and fsnotify_iter_{should|set}_report_type macros to set/test report_mask. This is going to be used for adding mark of another object type (super block mark). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
d9a6f30b |
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20-Apr-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: introduce marks iteration helpers Introduce helpers fsnotify_iter_select_report_types() and fsnotify_iter_next() to abstract the inode/vfsmount marks merged list iteration. This is a preparation patch before generalizing mark list iteration to more mark object types (i.e. super block marks). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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5b0457ad |
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20-Apr-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: remove redundant arguments to handle_event() inode_mark and vfsmount_mark arguments are passed to handle_event() operation as function arguments as well as on iter_info struct. The difference is that iter_info struct may contain marks that should not be handled and are represented as NULL arguments to inode_mark or vfsmount_mark. Instead of passing the inode_mark and vfsmount_mark arguments, add a report_mask member to iter_info struct to indicate which marks should be handled, versus marks that should only be kept alive during user wait. This change is going to be used for passing more mark types with handle_event() (i.e. super block marks). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
92183a42 |
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05-Apr-2018 |
Amir Goldstein <amir73il@gmail.com> |
fsnotify: fix ignore mask logic in send_to_group() The ignore mask logic in send_to_group() does not match the logic in fanotify_should_send_event(). In the latter, a vfsmount mark ignore mask precedes an inode mark mask and in the former, it does not. That difference may cause events to be sent to fanotify backend for no reason. Fix the logic in send_to_group() to match that of fanotify_should_send_event(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
1751e8a6 |
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27-Nov-2017 |
Linus Torvalds <torvalds@linux-foundation.org> |
Rename superblock flags (MS_xyz -> SB_xyz) This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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3427ce71 |
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30-Oct-2017 |
Miklos Szeredi <mszeredi@redhat.com> |
fsnotify: clean up fsnotify() Use helpers to get first and next marks from connector. Also get rid of inode_node/vfsmount_node local variables, which just refers to the same objects as iter_info. There was an srcu_dereference() for foo_node, but that's completely superfluous since we've already done it when obtaining foo_node. Also get rid of inode_group/vfsmount_group local variables; checking against non-NULL for these is the same as checking against non-NULL inode_mark/vfsmount_mark. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
0d6ec079 |
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30-Oct-2017 |
Miklos Szeredi <mszeredi@redhat.com> |
fsnotify: pin both inode and vfsmount mark We may fail to pin one of the marks in fsnotify_prepare_user_wait() when dropping the srcu read lock, resulting in use after free at the next iteration. Solution is to store both marks in iter_info instead of just the one we'll be sending the event for. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 9385a84d7e1f ("fsnotify: Pass fsnotify_iter_info into handle_event handler") Cc: <stable@vger.kernel.org> # v4.12 Signed-off-by: Jan Kara <jack@suse.cz>
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#
49d31c2f |
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07-Jul-2017 |
Al Viro <viro@zeniv.linux.org.uk> |
dentry name snapshots take_dentry_name_snapshot() takes a safe snapshot of dentry name; if the name is a short one, it gets copied into caller-supplied structure, otherwise an extra reference to external name is grabbed (those are never modified). In either case the pointer to stable string is stored into the same structure. dentry must be held by the caller of take_dentry_name_snapshot(), but may be freely dropped afterwards - the snapshot will stay until destroyed by release_dentry_name_snapshot(). Intended use: struct name_snapshot s; take_dentry_name_snapshot(&s, dentry); ... access s.name ... release_dentry_name_snapshot(&s); Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name to pass down with event. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
ebb3b47e |
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21-Dec-2016 |
Jan Kara <jack@suse.cz> |
fsnotify: Drop inode_mark.c inode_mark.c now contains only a single function. Move it to fs/notify/fsnotify.c and remove inode_mark.c. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
9385a84d |
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10-Nov-2016 |
Jan Kara <jack@suse.cz> |
fsnotify: Pass fsnotify_iter_info into handle_event handler Pass fsnotify_iter_info into ->handle_event() handler so that it can release and reacquire SRCU lock via fsnotify_prepare_user_wait() and fsnotify_finish_user_wait() functions. These functions also make sure current marks are appropriately pinned so that iteration protected by srcu in fsnotify() stays safe. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
08991e83 |
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01-Feb-2017 |
Jan Kara <jack@suse.cz> |
fsnotify: Free fsnotify_mark_connector when there is no mark attached Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
9dd813c1 |
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13-Mar-2017 |
Jan Kara <jack@suse.cz> |
fsnotify: Move mark list head from object into dedicated structure Currently notification marks are attached to object (inode or vfsmnt) by a hlist_head in the object. The list is also protected by a spinlock in the object. So while there is any mark attached to the list of marks, the object must be pinned in memory (and thus e.g. last iput() deleting inode cannot happen). Also for list iteration in fsnotify() to work, we must hold fsnotify_mark_srcu lock so that mark itself and mark->obj_list.next cannot get freed. Thus we are required to wait for response to fanotify events from userspace process with fsnotify_mark_srcu lock held. That causes issues when userspace process is buggy and does not reply to some event - basically the whole notification subsystem gets eventually stuck. So to be able to drop fsnotify_mark_srcu lock while waiting for response, we have to pin the mark in memory and make sure it stays in the object list (as removing the mark waiting for response could lead to lost notification events for groups later in the list). However we don't want inode reclaim to block on such mark as that would lead to system just locking up elsewhere. This commit is the first in the series that paves way towards solving these conflicting lifetime needs. Instead of anchoring the list of marks directly in the object, we anchor it in a dedicated structure (fsnotify_mark_connector) and just point to that structure from the object. The following commits will also add spinlock protecting the list and object pointer to the structure. Reviewed-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
12c7f9dc |
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20-Nov-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify fsnotify_parent() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
e637835e |
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20-Nov-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
fsnotify(): constify 'data' Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
925d1132 |
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04-Sep-2015 |
Jan Kara <jack@suse.com> |
fsnotify: remove mark->free_list Free list is used when all marks on given inode / mount should be destroyed when inode / mount is going away. However we can free all of the marks without using a special list with some care. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7c49b861 |
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04-Sep-2015 |
Dave Hansen <dave.hansen@linux.intel.com> |
fs/notify: optimize inotify/fsnotify code for unwatched files I have a _tiny_ microbenchmark that sits in a loop and writes single bytes to a file. Writing one byte to a tmpfs file is around 2x slower than reading one byte from a file, which is a _bit_ more than I expecte. This is a dumb benchmark, but I think it's hard to deny that write() is a hot path and we should avoid unnecessary overhead there. I did a 'perf record' of 30-second samples of read and write. The top item in a diffprofile is srcu_read_lock() from fsnotify(). There are active inotify fd's from systemd, but nothing is actually listening to the file or its part of the filesystem. I *think* we can avoid taking the srcu_read_lock() for the common case where there are no actual marks on the file. This means that there will both be nothing to notify for *and* implies that there is no need for clearing the ignore mask. This patch gave a 13.1% speedup in writes/second on my test, which is an improvement from the 10.8% that I saw with the last version. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
0809ab69 |
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12-Dec-2014 |
Jan Kara <jack@suse.cz> |
fsnotify: unify inode and mount marks handling There's a lot of common code in inode and mount marks handling. Factor it out to a common helper function. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
8edc6e16 |
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13-Nov-2014 |
Jan Kara <jack@suse.cz> |
fanotify: fix notification of groups with inode & mount marks fsnotify() needs to merge inode and mount marks lists when notifying groups about events so that ignore masks from inode marks are reflected in mount mark notifications and groups are notified in proper order (according to priorities). Currently the sorting of the lists done by fsnotify_add_inode_mark() / fsnotify_add_vfsmount_mark() and fsnotify() differed which resulted ignore masks not being used in some cases. Fix the problem by always using the same comparison function when sorting / merging the mark lists. Thanks to Heinrich Schuchardt for improvements of my patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=87721 Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
946e51f2 |
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26-Oct-2014 |
Al Viro <viro@zeniv.linux.org.uk> |
move d_rcu from overlapping d_child to overlapping d_alias Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
45a22f4c |
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17-Feb-2014 |
Jan Kara <jack@suse.cz> |
inotify: Fix reporting of cookies for inotify events My rework of handling of notification events (namely commit 7053aee26a35 "fsnotify: do not share events between notification groups") broke sending of cookies with inotify events. We didn't propagate the value passed to fsnotify() properly and passed 4 uninitialized bytes to userspace instead (so it is also an information leak). Sadly I didn't notice this during my testing because inotify cookies aren't used very much and LTP inotify tests ignore them. Fix the problem by passing the cookie value properly. Fixes: 7053aee26a3548ebaba046ae2e52396ccf56ac6c Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
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#
83c4c4b0 |
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21-Jan-2014 |
Jan Kara <jack@suse.cz> |
fsnotify: remove .should_send_event callback After removing event structure creation from the generic layer there is no reason for separate .should_send_event and .handle_event callbacks. So just remove the first one. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7053aee2 |
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21-Jan-2014 |
Jan Kara <jack@suse.cz> |
fsnotify: do not share events between notification groups Currently fsnotify framework creates one event structure for each notification event and links this event into all interested notification groups. This is done so that we save memory when several notification groups are interested in the event. However the need for event structure shared between inotify & fanotify bloats the event structure so the result is often higher memory consumption. Another problem is that fsnotify framework keeps path references with outstanding events so that fanotify can return open file descriptors with its events. This has the undesirable effect that filesystem cannot be unmounted while there are outstanding events - a regression for inotify compared to a situation before it was converted to fsnotify framework. For fanotify this problem is hard to avoid and users of fanotify should kind of expect this behavior when they ask for file descriptors from notified files. This patch changes fsnotify and its users to create separate event structure for each group. This allows for much simpler code (~400 lines removed by this patch) and also smaller event structures. For example on 64-bit system original struct fsnotify_event consumes 120 bytes, plus additional space for file name, additional 24 bytes for second and each subsequent group linking the event, and additional 32 bytes for each inotify group for private data. After the conversion inotify event consumes 48 bytes plus space for file name which is considerably less memory unless file names are long and there are several groups interested in the events (both of which are uncommon). Fanotify event fits in 56 bytes after the conversion (fanotify doesn't care about file names so its events don't have to have it allocated). A win unless there are four or more fanotify groups interested in the event. The conversion also solves the problem with unmount when only inotify is used as we don't have to grab path references for inotify events. [hughd@google.com: fanotify: fix corruption preventing startup] Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b67bfe0d |
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27-Feb-2013 |
Sasha Levin <sasha.levin@oracle.com> |
hlist: drop the node parameter from iterators I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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b3d9b7a3 |
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09-Jun-2012 |
Al Viro <viro@zeniv.linux.org.uk> |
vfs: switch i_dentry/d_alias to hlist Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
fd657170 |
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29-May-2012 |
Dan Carpenter <dan.carpenter@oracle.com> |
fsnotify: remove unused parameter from send_to_group() We don't use "mnt" anymore in send_to_group() after 1968f5eed5 ("fanotify: use both marks when possible") was applied. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
c63181e6 |
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25-Nov-2011 |
Al Viro <viro@zeniv.linux.org.uk> |
vfs: move fsnotify junk to struct mount Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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873feea0 |
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06-Jan-2011 |
Nick Piggin <npiggin@kernel.dk> |
fs: dcache per-inode inode alias locking dcache_inode_lock can be replaced with per-inode locking. Use existing inode->i_lock for this. This is slightly non-trivial because we sometimes need to find the inode from the dentry, which requires d_inode to be stabilised (either with refcount or d_lock). Signed-off-by: Nick Piggin <npiggin@kernel.dk>
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b5c84bf6 |
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06-Jan-2011 |
Nick Piggin <npiggin@kernel.dk> |
fs: dcache remove dcache_lock dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
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b23fb0a6 |
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06-Jan-2011 |
Nick Piggin <npiggin@kernel.dk> |
fs: scale inode alias list Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list from concurrent modification. d_alias is also protected by d_lock. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
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2fd6b7f5 |
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06-Jan-2011 |
Nick Piggin <npiggin@kernel.dk> |
fs: dcache scale subdirs Protect d_subdirs and d_child with d_lock, except in filesystems that aren't using dcache_lock for these anyway (eg. using i_mutex). Note: if we change the locking rule in future so that ->d_child protection is provided only with ->d_parent->d_lock, it may allow us to reduce some locking. But it would be an exception to an otherwise regular locking scheme, so we'd have to see some good results. Probably not worthwhile. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
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52420392 |
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28-Oct-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: call fsnotify_parent in perm events fsnotify perm events do not call fsnotify parent. That means you cannot register a perm event on a directory and enforce permissions on all inodes in that directory. This patch fixes that situation. Signed-off-by: Eric Paris <eparis@redhat.com>
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ff8bcbd0 |
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28-Oct-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: correctly handle return codes from listeners When fsnotify groups return errors they are ignored. For permissions events these should be passed back up the stack, but for most events these should continue to be ignored. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
4d4eb366 |
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10-Oct-2010 |
Christoph Hellwig <hch@infradead.org> |
fsnotify: use dget_parent Use dget_parent instead of opencoding it. This simplifies the code, but more importanly prepares for the more complicated locking for a parent dget in the dcache scale patch series. It means we do grab a reference to the parent now if need to be watched, but not with the specified mask. If this turns out to be a problem we'll have to revisit it, but for now let's keep as much as possible dcache internals inside dcache.[ch]. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
92b4678e |
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27-Aug-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: drop two useless bools in the fnsotify main loop The fsnotify main loop has 2 bools which indicated if we processed the inode or vfsmount mark in that particular pass through the loop. These bool can we replaced with the inode_group and vfsmount_group variables and actually make the code a little easier to understand. Signed-off-by: Eric Paris <eparis@redhat.com>
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f72adfd5 |
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27-Aug-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: fix list walk order Marks were stored on the inode and vfsmonut mark list in order from highest memory address to lowest memory address. The code to walk those lists thought they were in order from lowest to highest with unpredictable results when trying to match up marks from each. It was possible that extra events would be sent to userspace when inode marks ignoring events wouldn't get matched with the vfsmount marks. This problem only affected fanotify when using both vfsmount and inode marks simultaneously. Signed-off-by: Eric Paris <eparis@redhat.com>
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84e1ab4d |
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17-Aug-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: fix ignored mask handling between inode and vfsmount marks The interesting 2 list lockstep walking didn't quite work out if the inode marks only had ignores and the vfsmount list requested events. The code to shortcut list traversal would not run the inode list since it didn't have real event requests. This code forces inode list traversal when a vfsmount mark matches the event type. Maybe we could add an i_fsnotify_ignored_mask field to struct inode to get the shortcut back, but it doesn't seem worth it to grow struct inode again. I bet with the recent changes to lock the way we do now it would actually not be a major perf hit to just drop i_fsnotify_mark_mask altogether. But that is for another day. Signed-off-by: Eric Paris <eparis@redhat.com>
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5f3f259f |
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17-Aug-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: reset used_inode and used_vfsmount on each pass The fsnotify main loop has 2 booleans which tell if a particular mark was sent to the listeners or if it should be processed in the next pass. The problem is that the booleans were not reset on each traversal of the loop. So marks could get skipped even when they were not sent to the notifiers. Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com> Signed-off-by: Eric Paris <eparis@redhat.com>
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faa9560a |
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17-Aug-2010 |
Eric Paris <eparis@redhat.com> |
fanotify: do not dereference inode_mark when it is unset The fanotify code is supposed to get the group from the mark. It accidentally only used the inode_mark. If the vfsmount_mark was set but not the inode_mark it would deref the NULL inode_mark. Get the group from the correct place. Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com> Signed-off-by: Eric Paris <eparis@redhat.com>
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2069601b |
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12-Aug-2010 |
Linus Torvalds <torvalds@linux-foundation.org> |
Revert "fsnotify: store struct file not struct path" This reverts commit 3bcf3860a4ff9bbc522820b4b765e65e4deceb3e (and the accompanying commit c1e5c954020e "vfs/fsnotify: fsnotify_close can delay the final work in fput" that was a horribly ugly hack to make it work at all). The 'struct file' approach not only causes that disgusting hack, it somehow breaks pulseaudio, probably due to some other subtlety with f_count handling. Fix up various conflicts due to later fsnotify work. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1968f5ee |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fanotify: use both marks when possible fanotify currently, when given a vfsmount_mark will look up (if it exists) the corresponding inode mark. This patch drops that lookup and uses the mark provided. Signed-off-by: Eric Paris <eparis@redhat.com>
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ce8f76fb |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: pass both the vfsmount mark and inode mark should_send_event() and handle_event() will both need to look up the inode event if they get a vfsmount event. Lets just pass both at the same time since we have them both after walking the lists in lockstep. Signed-off-by: Eric Paris <eparis@redhat.com>
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613a807f |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: walk the inode and vfsmount lists simultaneously We currently walk the list of marks on an inode followed by the list of marks on the vfsmount. These are in order (by the memory address of the group) so lets walk them both together. Eventually we can pass both the inode mark and the vfsmount mark to helpers simultaneously. Signed-off-by: Eric Paris <eparis@redhat.com>
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84a5b68e |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: rework ignored mark flushing currently ignored_mark clearing is done in a seperate list traversal before the actual list traversal to send events. There is no need for this. Do them at the same time. Signed-off-by: Eric Paris <eparis@redhat.com>
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02436668 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: remove global fsnotify groups lists The global fsnotify groups lists were invented as a way to increase the performance of fsnotify by shortcutting events which were not interesting. With the changes to walk the object lists rather than global groups lists these shortcuts are not useful. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
03930979 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: remove the global masks Because we walk the object->fsnotify_marks list instead of the global fsnotify groups list we don't need the fsnotify_inode_mask and fsnotify_vfsmount_mask as these were simply shortcuts in fsnotify() for performance. They are now extra checks, rip them out. Signed-off-by: Eric Paris <eparis@redhat.com>
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2612abb5 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: cleanup should_send_event The change to use srcu and walk the object list rather than the global fsnotify_group list means that should_send_event is no longer needed for a number of groups and can be simplified for others. Do that. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
3a9b16b4 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: send fsnotify_mark to groups in event handling functions With the change of fsnotify to use srcu walking the marks list instead of walking the global groups list we now know the mark in question. The code can send the mark to the group's handling functions and the groups won't have to find those marks themselves. Signed-off-by: Eric Paris <eparis@redhat.com>
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75c1be48 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: srcu to protect read side of inode and vfsmount locks Currently reading the inode->i_fsnotify_marks or vfsmount->mnt_fsnotify_marks lists are protected by a spinlock on both the read and the write side. This patch protects the read side of those lists with a new single srcu. Signed-off-by: Eric Paris <eparis@redhat.com>
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3bcf3860 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: store struct file not struct path Al explains that calling dentry_open() with a mnt/dentry pair is only garunteed to be safe if they are already used in an open struct file. To make sure this is the case don't store and use a struct path in fsnotify, always use a struct file. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
5ba08e2e |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: add pr_debug throughout It can be hard to debug fsnotify since there are so few printks. Use pr_debug to allow for dynamic debugging. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
20dee624 |
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28-Jul-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: check to make sure all fsnotify bits are unique This patch adds a check to make sure that all fsnotify bits are unique and we cannot accidentally use the same bit for 2 different fsnotify event types. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
98b5c10d |
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23-Mar-2010 |
Jean-Christophe Dubois <jcd@tribudubois.net> |
fanotify: do not always return 0 in fsnotify It seems to me you are always returning 0 in fsnotify, when you should return the error (EPERM) returned by fanotify. Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net> Signed-off-by: Eric Paris <eparis@redhat.com>
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#
c4ec54b4 |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: new fsnotify hooks and events types for access decisions introduce a new fsnotify hook, fsnotify_perm(), which is called from the security code. This hook is used to allow fsnotify groups to make access control decisions about events on the system. We also must change the generic fsnotify function to return an error code if we intend these hooks to be in any way useful. Signed-off-by: Eric Paris <eparis@redhat.com>
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#
59b0df21 |
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07-Feb-2010 |
Eric Paris <eparis@redhat.com> |
fsnotify: use unsigned char * for dentry->d_name.name fsnotify was using char * when it passed around the d_name.name string internally but it is actually an unsigned char *. This patch switches fsnotify to use unsigned and should silence some pointer signess warnings which have popped out of xfs. I do not add -Wpointer-sign to the fsnotify code as there are still issues with kstrdup and strlen which would pop out needless warnings. Signed-off-by: Eric Paris <eparis@redhat.com>
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c908370f |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: allow ignored_mask to survive modification Some inodes a group may want to never hear about a set of events even if the inode is modified. We add a new mark flag which indicates that these marks should not have their ignored_mask cleared on modification. Signed-off-by: Eric Paris <eparis@redhat.com>
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e8983861 |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: clear ignored mask on modify On inode modification we clear the ignored mask for all of the marks on the inode. This allows userspace to ignore accesses to inodes until there is something different. Signed-off-by: Eric Paris <eparis@redhat.com>
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ca9c726e |
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17-Dec-2009 |
Andreas Gruenbacher <agruen@suse.de> |
fsnotify: Infrastructure for per-mount watches Per-mount watches allow groups to listen to fsnotify events on an entire mount. This patch simply adds and initializes the fields needed in the vfsmount struct to make this happen. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
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2504c5d6 |
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17-Dec-2009 |
Andreas Gruenbacher <agruen@suse.de> |
fsnotify/vfsmount: add fsnotify fields to struct vfsmount This patch adds the list and mask fields needed to support vfsmount marks. These are the same fields fsnotify needs on an inode. They are not used, just declared and we note where the cleanup hook should be (the function is not yet defined) Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
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72acc854 |
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17-Dec-2009 |
Andreas Gruenbacher <agruen@suse.de> |
fsnotify: kill FSNOTIFY_EVENT_FILE Some fsnotify operations send a struct file. This is more information than we technically need. We instead send a struct path in all cases instead of sometimes a path and sometimes a file. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
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3a9fb89f |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: include vfsmount in should_send_event when appropriate To ensure that a group will not duplicate events when it receives it based on the vfsmount and the inode should_send_event test we should distinguish those two cases. We pass a vfsmount to this function so groups can make their own determinations. Signed-off-by: Eric Paris <eparis@redhat.com>
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7131485a |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: mount point listeners list and global mask currently all of the notification systems implemented select which inodes they care about and receive messages only about those inodes (or the children of those inodes.) This patch begins to flesh out fsnotify support for the concept of listeners that want to hear notification for an inode accessed below a given monut point. This patch implements a second list of fsnotify groups to hold these types of groups and a second global mask to hold the events of interest for this type of group. The reason we want a second group list and mask is because the inode based notification should_send_event support which makes each group look for a mark on the given inode. With one nfsmount listener that means that every group would have to take the inode->i_lock, look for their mark, not find one, and return for every operation. By seperating vfsmount from inode listeners only when there is a inode listener will the inode groups have to look for their mark and take the inode lock. vfsmount listeners will have to grab the lock and look for a mark but there should be fewer of them, and one vfsmount listener won't cause the i_lock to be grabbed and released for every fsnotify group on every io operation. Signed-off-by: Eric Paris <eparis@redhat.com>
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19c2a0e1 |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: rename fsnotify_groups to fsnotify_inode_groups Simple renaming patch. fsnotify is about to support mount point listeners so I am renaming fsnotify_groups and fsnotify_mask to indicate these are lists used only for groups which have watches on inodes. Signed-off-by: Eric Paris <eparis@redhat.com>
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28c60e37 |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: send struct file when sending events to parents when possible fanotify needs a path in order to open an fd to the object which changed. Currently notifications to inode's parents are done using only the inode. For some parental notification we have the entire file, send that so fanotify can use it. Signed-off-by: Eric Paris <eparis@redhat.com>
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8112e2d6 |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: include data in should_send calls fanotify is going to need to look at file->private_data to know if an event should be sent or not. This passes the data (which might be a file, dentry, inode, or none) to the should_send function calls so fanotify can get that information when available Signed-off-by: Eric Paris <eparis@redhat.com>
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7b0a04fb |
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17-Dec-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: provide the data type to should_send_event fanotify is only interested in event types which contain enough information to open the original file in the context of the fanotify listener. Since fanotify may not want to send events if that data isn't present we pass the data type to the should_send_event function call so fanotify can express its lack of interest. Signed-off-by: Eric Paris <eparis@redhat.com>
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5a0e3ad6 |
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24-Mar-2010 |
Tejun Heo <tj@kernel.org> |
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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f44aebcc |
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15-Jul-2009 |
Eric Paris <eparis@redhat.com> |
inotify: use GFP_NOFS under potential memory pressure inotify can have a watchs removed under filesystem reclaim. ================================= [ INFO: inconsistent lock state ] 2.6.31-rc2 #16 --------------------------------- inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage. khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes: (iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3 {IN-RECLAIM_FS-W} state was registered at: [<c10536ab>] __lock_acquire+0x2c9/0xac4 [<c1053f45>] lock_acquire+0x9f/0xc2 [<c1308872>] __mutex_lock_common+0x2d/0x323 [<c1308c00>] mutex_lock_nested+0x2e/0x36 [<c10ba6ff>] shrink_icache_memory+0x38/0x1b2 [<c108bfb6>] shrink_slab+0xe2/0x13c [<c108c3e1>] kswapd+0x3d1/0x55d [<c10449b5>] kthread+0x66/0x6b [<c1003fdf>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff Two things are needed to fix this. First we need a method to tell fsnotify_create_event() to use GFP_NOFS and second we need to stop using one global IN_IGNORED event and allocate them one at a time. This solves current issues with multiple IN_IGNORED on a queue having tail drop problems and simplifies the allocations since we don't have to worry about two tasks opperating on the IGNORED event concurrently. Signed-off-by: Eric Paris <eparis@redhat.com>
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e42e2773 |
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11-Jun-2009 |
Eric Paris <eparis@redhat.com> |
inotify/dnotify: should_send_event shouldn't match on FS_EVENT_ON_CHILD inotify and dnotify will both indicate that they want any event which came from a child inode. The fix is to mask off FS_EVENT_ON_CHILD when deciding if inotify or dnotify is interested in a given event. Signed-off-by: Eric Paris <eparis@redhat.com>
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47882c6f |
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21-May-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: add correlations between events As part of the standard inotify events it includes a correlation cookie between two dentry move operations. This patch includes the same behaviour in fsnotify events. It is needed so that inotify userspace can be implemented on top of fsnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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62ffe5df |
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21-May-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: include pathnames with entries when possible When inotify wants to send events to a directory about a child it includes the name of the original file. This patch collects that filename and makes it available for notification. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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c28f7e56 |
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21-May-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: parent event notification inotify and dnotify both use a similar parent notification mechanism. We add a generic parent notification mechanism to fsnotify for both of these to use. This new machanism also adds the dentry flag optimization which exists for inotify to dnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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3be25f49 |
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21-May-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: add marks to inodes so groups can interpret how to handle those inodes This patch creates a way for fsnotify groups to attach marks to inodes. These marks have little meaning to the generic fsnotify infrastructure and thus their meaning should be interpreted by the group that attached them to the inode's list. dnotify and inotify will make use of these markings to indicate which inodes are of interest to their respective groups. But this implementation has the useful property that in the future other listeners could actually use the marks for the exact opposite reason, aka to indicate which inodes it had NO interest in. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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90586523 |
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21-May-2009 |
Eric Paris <eparis@redhat.com> |
fsnotify: unified filesystem notification backend fsnotify is a backend for filesystem notification. fsnotify does not provide any userspace interface but does provide the basis needed for other notification schemes such as dnotify. fsnotify can be extended to be the backend for inotify or the upcoming fanotify. fsnotify provides a mechanism for "groups" to register for some set of filesystem events and to then deliver those events to those groups for processing. fsnotify has a number of benefits, the first being actually shrinking the size of an inode. Before fsnotify to support both dnotify and inotify an inode had unsigned long i_dnotify_mask; /* Directory notify events */ struct dnotify_struct *i_dnotify; /* for directory notifications */ struct list_head inotify_watches; /* watches on this inode */ struct mutex inotify_mutex; /* protects the watches list But with fsnotify this same functionallity (and more) is done with just __u32 i_fsnotify_mask; /* all events for this inode */ struct hlist_head i_fsnotify_mark_entries; /* marks on this inode */ That's right, inotify, dnotify, and fanotify all in 64 bits. We used that much space just in inotify_watches alone, before this patch set. fsnotify object lifetime and locking is MUCH better than what we have today. inotify locking is incredibly complex. See 8f7b0ba1c8539 as an example of what's been busted since inception. inotify needs to know internal semantics of superblock destruction and unmounting to function. The inode pinning and vfs contortions are horrible. no fsnotify implementers do allocation under locks. This means things like f04b30de3 which (due to an overabundance of caution) changes GFP_KERNEL to GFP_NOFS can be reverted. There are no longer any allocation rules when using or implementing your own fsnotify listener. fsnotify paves the way for fanotify. In brief fanotify is a notification mechanism that delivers the lisener both an 'event' and an open file descriptor to the object in question. This means that fanotify is pathname agnostic. Some on lkml may not care for the original companies or users that pushed for TALPA, but fanotify was designed with flexibility and input for other users in mind. The readahead group expressed interest in fanotify as it could be used to profile disk access on boot without breaking the audit system. The desktop search groups have also expressed interest in fanotify as it solves a number of the race conditions and problems present with managing inotify when more than a limited number of specific files are of interest. fanotify can provide for a userspace access control system which makes it a clean interface for AV vendors to hook without trying to do binary patching on the syscall table, LSM, and everywhere else they do their things today. With this patch series fanotify can be implemented in less than 1200 lines of easy to review code. Almost all of which is the socket based user interface. This patch series builds fsnotify to the point that it can implement dnotify and inotify_user. Patches exist and will be sent soon after acceptance to finish the in kernel inotify conversion (audit) and implement fanotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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