user/sven/linux.git/include/linux/fsnotify_backend.h, branch v5.18.19

fsnotify: introduce mark type iterator

2022-06-25T13:29:47Z

commit 14362a2541797cf9df0e86fb12dcd7950baf566e upstream. 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 Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20220511190213.831646-2-amir73il@gmail.com Signed-off-by: Greg Kroah-Hartman

fsnotify: optimize FS_MODIFY events with no ignored masks

2022-02-24T13:05:18Z

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 Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: fix merge with parent's ignored mask

2022-02-24T13:04:51Z

fsnotify_parent() does not consider the parent's mark at all unless the parent inode shows interest in events on children and in the specific event. So unless parent added an event to both its mark mask and ignored mask, the event will not be ignored. Fix this by declaring the interest of an object in an event when the event is in either a mark mask or ignored mask. Link: https://lore.kernel.org/r/20220223151438.790268-2-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: generate FS_RENAME event with rich information

2021-12-15T13:04:27Z

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 Signed-off-by: Jan Kara

fsnotify: separate mark iterator type from object type enum

2021-12-15T13:04:06Z

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 Signed-off-by: Jan Kara

fsnotify: clarify object type argument

2021-12-15T13:04:03Z

In preparation for separating object type from iterator type, rename some 'type' arguments in functions to 'obj_type' and remove the unused interface to clear marks by object type mask. Link: https://lore.kernel.org/r/20211129201537.1932819-2-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: Pre-allocate pool of error events

2021-10-27T10:35:05Z

Pre-allocate slots for file system errors to have greater chances of succeeding, since error events can happen in GFP_NOFS context. This patch introduces a group-wide mempool of error events, shared by all FAN_FS_ERROR marks in this group. Link: https://lore.kernel.org/r/20211025192746.66445-20-krisman@collabora.com Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara

fsnotify: Support FS_ERROR event type

2021-10-27T10:34:49Z

Expose a new type of fsnotify event for filesystems to report errors for userspace monitoring tools. fanotify will send this type of notification for FAN_FS_ERROR events. This also introduce a helper for generating the new event. Link: https://lore.kernel.org/r/20211025192746.66445-18-krisman@collabora.com Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara

fsnotify: Pass group argument to free_event

2021-10-27T10:34:18Z

For group-wide mempool backed events, like FS_ERROR, the free_event callback will need to reference the group's mempool to free the memory. Wire that argument into the current callers. Link: https://lore.kernel.org/r/20211025192746.66445-13-krisman@collabora.com Reviewed-by: Jan Kara Reviewed-by: Amir Goldstein Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara

fsnotify: Protect fsnotify_handle_inode_event from no-inode events

2021-10-27T10:34:12Z

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 Signed-off-by: Gabriel Krisman Bertazi Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Jan Kara