kernel/include/linux/fsnotify_backend.h, branch linux-6.9.y

fsnotify: Fix misspelling of "writable"

2024-03-06T12:13:05Z

Several file system notification system headers have "writable" misspelled as "writtable" in the comments. This patch fixes it in the fsnotify header. Signed-off-by: Vicki Pfau Signed-off-by: Jan Kara Message-Id: <20240306020831.1404033-2-vi@endrift.com>

fanotify: allow "weak" fsid when watching a single filesystem

2023-12-01T09:55:21Z

So far, fanotify returns -ENODEV or -EXDEV when trying to set a mark on a filesystem with a "weak" fsid, namely, zero fsid (e.g. fuse), or non-uniform fsid (e.g. btrfs non-root subvol). When group is watching inodes all from the same filesystem (or subvol), allow adding inode marks with "weak" fsid, because there is no ambiguity regarding which filesystem reports the event. The first mark added to a group determines if this group is single or multi filesystem, depending on the fsid at the path of the added mark. If the first mark added has a "strong" fsid, marks with "weak" fsid cannot be added and vice versa. If the first mark added has a "weak" fsid, following marks must have the same "weak" fsid and the same sb as the first mark. Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20231130165619.3386452-3-amir73il@gmail.com>

fanotify: store fsid in mark instead of in connector

2023-12-01T09:55:21Z

Some filesystems like fuse and nfs have zero or non-unique fsid. We would like to avoid reporting ambiguous fsid in events, so we need to avoid marking objects with same fsid and different sb. To make this easier to enforce, store the fsid in the marks of the group instead of in the shared conenctor. Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20231130165619.3386452-2-amir73il@gmail.com>

fanotify: Remove unused extern declaration fsnotify_get_conn_fsid()

2023-08-01T21:46:17Z

This is never used, so can remove it. Signed-off-by: YueHaibing Signed-off-by: Jan Kara Message-Id: <20230725135528.25996-1-yuehaibing@huawei.com>

fanotify: prepare for setting event flags in ignore mask

2022-07-01T12:51:13Z

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 Signed-off-by: Jan Kara

fsnotify: introduce mark type iterator

2022-05-18T13:07:43Z

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

fsnotify: allow adding an inode mark without pinning inode

2022-04-25T12:42:45Z

fsnotify_add_mark() and variants implicitly take a reference on inode when attaching a mark to an inode. Make that behavior opt-out with the mark flag FSNOTIFY_MARK_FLAG_NO_IREF. Instead of taking the inode reference when attaching connector to inode and dropping the inode reference when detaching connector from inode, take the inode reference on attach of the first mark that wants to hold an inode reference and drop the inode reference on detach of the last mark that wants to hold an inode reference. Backends can "upgrade" an existing mark to take an inode reference, but cannot "downgrade" a mark with inode reference to release the refernce. This leaves the choice to the backend whether or not to pin the inode when adding an inode mark. This is intended to be used when adding a mark with ignored mask that is used for optimization in cases where group can afford getting unneeded events and reinstate the mark with ignored mask when inode is accessed again after being evicted. Link: https://lore.kernel.org/r/20220422120327.3459282-12-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: create helpers for group mark_mutex lock

2022-04-25T12:37:22Z

Create helpers to take and release the group mark_mutex lock. Define a flag FSNOTIFY_GROUP_NOFS in fsnotify_group that determines if the mark_mutex lock is fs reclaim safe or not. If not safe, the lock helpers take the lock and disable direct fs reclaim. In that case we annotate the mutex with a different lockdep class to express to lockdep that an allocation of mark of an fs reclaim safe group may take the group lock of another "NOFS" group to evict inodes. For now, converted only the callers in common code and no backend defines the NOFS flag. It is intended to be set by fanotify for evictable marks support. Link: https://lore.kernel.org/r/20220422120327.3459282-7-amir73il@gmail.com Suggested-by: Jan Kara Link: https://lore.kernel.org/r/20220321112310.vpr7oxro2xkz5llh@quack3.lan/ Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: make allow_dups a property of the group

2022-04-25T12:37:18Z

Instead of passing the allow_dups argument to fsnotify_add_mark() as an argument, define the group flag FSNOTIFY_GROUP_DUPS to express the allow_dups behavior and set this behavior at group creation time for all calls of fsnotify_add_mark(). Rename the allow_dups argument to generic add_flags argument for future use. Link: https://lore.kernel.org/r/20220422120327.3459282-6-amir73il@gmail.com Suggested-by: Jan Kara Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: pass flags argument to fsnotify_alloc_group()

2022-04-25T12:37:12Z

Add flags argument to fsnotify_alloc_group(), define and use the flag FSNOTIFY_GROUP_USER in inotify and fanotify instead of the helper fsnotify_alloc_user_group() to indicate user allocation. Although the flag FSNOTIFY_GROUP_USER is currently not used after group allocation, we store the flags argument in the group struct for future use of other group flags. Link: https://lore.kernel.org/r/20220422120327.3459282-5-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara