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path: root/include/linux/fsnotify_backend.h
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* fsnotify: add group prioritiesEric Paris2010-07-28
| | | | | | | | | | | | | | | | This introduces an ordering to fsnotify groups. With purely asynchronous notification based "things" implementing fsnotify (inotify, dnotify) ordering isn't particularly important. But if people want to use fsnotify for the basis of sycronous notification or blocking notification ordering becomes important. eg. A Hierarchical Storage Management listener would need to get its event before an AV scanner could get its event (since the HSM would need to bring the data in for the AV scanner to scan.) Typically asynchronous notification would want to run after the AV scanner made any relevant access decisions so as to not send notification about an event that was denied. Signed-off-by: Eric Paris <eparis@redhat.com>
* fanotify: clear all fanotify marksEric Paris2010-07-28
| | | | | | | | | fanotify listeners may want to clear all marks. They may want to do this to destroy all of their inode marks which have nothing but ignores. Realistically this is useful for av vendors who update policy and want to clear all of their cached allows. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: allow ignored_mask to survive modificationEric Paris2010-07-28
| | | | | | | | 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>
* fsnotify: ignored_mask - excluding notificationEric Paris2010-07-28
| | | | | | | | | | | The ignored_mask is a new mask which is part of fsnotify marks. A group's should_send_event() function can use the ignored mask to determine that certain events are not of interest. In particular if a group registers a mask including FS_OPEN on a vfsmount they could add FS_OPEN to the ignored_mask for individual inodes and not send open events for those inodes. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: allow marks to not pin inodes in coreEric Paris2010-07-28
| | | | | | | | | | | | | | | | | inotify marks must pin inodes in core. dnotify doesn't technically need to since they are closed when the directory is closed. fanotify also need to pin inodes in core as it works today. But the next step is to introduce the concept of 'ignored masks' which is actually a mask of events for an inode of no interest. I claim that these should be liberally sent to the kernel and should not pin the inode in core. If the inode is brought back in the listener will get an event it may have thought excluded, but this is not a serious situation and one any listener should deal with. This patch lays the ground work for non-pinning inode marks by using lazy inode pinning. We do not pin a mark until it has a non-zero mask entry. If a listener new sets a mask we never pin the inode. Signed-off-by: Eric Paris <eparis@redhat.com>
* fanotify: should_send_event needs to handle vfsmountsEric Paris2010-07-28
| | | | | | | | currently should_send_event in fanotify only cares about marks on inodes. This patch extends that interface to indicate that it cares about events that happened on vfsmounts. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: Infrastructure for per-mount watchesAndreas Gruenbacher2010-07-28
| | | | | | | | | 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>
* fsnotify: vfsmount marks generic functionsEric Paris2010-07-28
| | | | | | | | Much like inode-mark.c has all of the code dealing with marks on inodes this patch adds a vfsmount-mark.c which has similar code but is intended for marks on vfsmounts. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: split generic and inode specific mark codeEric Paris2010-07-28
| | | | | | | | currently all marking is done by functions in inode-mark.c. Some of this is pretty generic and should be instead done in a generic function and we should only put the inode specific code in inode-mark.c Signed-off-by: Eric Paris <eparis@redhat.com>
* fanotify: Add pids to eventsAndreas Gruenbacher2010-07-28
| | | | | | | | Pass the process identifiers of the triggering processes to fanotify listeners: this information is useful for event filtering and logging. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: rename mark_entry to just markEric Paris2010-07-28
| | | | | | | previously I used mark_entry when talking about marks on inodes. The _entry is pretty useless. Just use "mark" instead. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: rename fsnotify_find_mark_entry to fsnotify_find_markEric Paris2010-07-28
| | | | | | the _entry portion of fsnotify functions is useless. Drop it. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: rename fsnotify_mark_entry to just fsnotify_markEric Paris2010-07-28
| | | | | | | The name is long and it serves no real purpose. So rename fsnotify_mark_entry to just fsnotify_mark. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: kill FSNOTIFY_EVENT_FILEAndreas Gruenbacher2010-07-28
| | | | | | | | | 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>
* fsnotify: add flags to fsnotify_mark_entriesEric Paris2010-07-28
| | | | | | | | To differentiate between inode and vfsmount (or other future) types of marks we add a flags field and set the inode bit on inode marks (the only currently supported type of mark) Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: add vfsmount specific fields to the fsnotify_mark_entry unionEric Paris2010-07-28
| | | | | | | | vfsmount marks need mostly the same data as inode specific fields, but for consistency and understandability we put that data in a vfsmount specific struct inside a union with inode specific data. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: put inode specific fields in an fsnotify_mark in a unionEric Paris2010-07-28
| | | | | | | | | The addition of marks on vfs mounts will be simplified if the inode specific parts of a mark and the vfsmnt specific parts of a mark are actually in a union so naming can be easy. This patch just implements the inode struct and the union. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: include vfsmount in should_send_event when appropriateEric Paris2010-07-28
| | | | | | | | | 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>
* fsnotify: mount point listeners list and global maskEric Paris2010-07-28
| | | | | | | | | | | | | | | | | | | | | | | 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>
* fsnotify: rename fsnotify_groups to fsnotify_inode_groupsEric Paris2010-07-28
| | | | | | | | 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>
* fsnotify: drop mask argument from fsnotify_alloc_groupEric Paris2010-07-28
| | | | | | | Nothing uses the mask argument to fsnotify_alloc_group. This patch drops that argument. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: fsnotify_obtain_group should be fsnotify_alloc_groupEric Paris2010-07-28
| | | | | | | | fsnotify_obtain_group was intended to be able to find an already existing group. Nothing uses that functionality. This just renames it to fsnotify_alloc_group so it is clear what it is doing. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: remove group_num altogetherEric Paris2010-07-28
| | | | | | | | The original fsnotify interface has a group-num which was intended to be able to find a group after it was added. I no longer think this is a necessary thing to do and so we remove the group_num. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: replace an event on a listEric Paris2010-07-28
| | | | | | | | | fanotify would like to clone events already on its notification list, make changes to the new event, and then replace the old event on the list with the new event. This patch implements the replace functionality of that process. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: clone existing eventsEric Paris2010-07-28
| | | | | | | | | | | fsnotify_clone_event will take an event, clone it, and return the cloned event to the caller. Since events may be in use by multiple fsnotify groups simultaneously certain event entries (such as the mask) cannot be changed after the event was created. Since fanotify would like to merge events happening on the same file it needs a new clean event to work with so it can change any fields it wishes. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: per group notification queue merge typesEric Paris2010-07-28
| | | | | | | | | | | inotify only wishes to merge a new event with the last event on the notification fifo. fanotify is willing to merge any events including by means of bitwise OR masks of multiple events together. This patch moves the inotify event merging logic out of the generic fsnotify notification.c and into the inotify code. This allows each use of fsnotify to provide their own merge functionality. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: send struct file when sending events to parents when possibleEric Paris2010-07-28
| | | | | | | | | 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>
* fsnotify: include data in should_send callsEric Paris2010-07-28
| | | | | | | | | 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>
* fsnotify: provide the data type to should_send_eventEric Paris2010-07-28
| | | | | | | | | | 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>
* audit: reimplement audit_trees using fsnotify rather than inotifyEric Paris2010-07-28
| | | | | | | Simply switch audit_trees from using inotify to using fsnotify for it's inode pinning and disappearing act information. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: allow addition of duplicate fsnotify marksEric Paris2010-07-28
| | | | | | | | | This patch allows a task to add a second fsnotify mark to an inode for the same group. This mark will be added to the end of the inode's list and this will never be found by the stand fsnotify_find_mark() function. This is useful if a user wants to add a new mark before removing the old one. Signed-off-by: Eric Paris <eparis@redhat.com>
* fsnotify: duplicate fsnotify_mark_entry data between 2 marksEric Paris2010-07-28
| | | | | | | Simple copy fsnotify information from one mark to another in preparation for the second mark to replace the first. Signed-off-by: Eric Paris <eparis@redhat.com>
* audit: convert audit watches to use fsnotify instead of inotifyEric Paris2010-07-28
| | | | | | | | Audit currently uses inotify to pin inodes in core and to detect when watched inodes are deleted or unmounted. This patch uses fsnotify instead of inotify. Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: use GFP_NOFS under potential memory pressureEric Paris2009-07-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs: allow d_instantiate to be called with negative parent dentryJeremy Kerr2009-06-29
| | | | | | | | | | | | | | The new fsnotify infrastructure (starting at 90586523) causes an oops in spufs, where we populate a directory with files before instantiating the directory itself. The new changes seem to have introduced an assumption that a dentry's parent will be positive when instantiating. This change makes it once again possible to d_instantiate a dentry with a negative parent, and brings __fsnotify_d_instantiate() into line with inotify_d_instantiate(), which already has this NULL check. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Eric Paris <eparis@redhat.com>
* inotify: reimplement inotify using fsnotifyEric Paris2009-06-11
| | | | | | | | | | | | Reimplement inotify_user using fsnotify. This should be feature for feature exactly the same as the original inotify_user. This does not make any changes to the in kernel inotify feature used by audit. Those patches (and the eventual removal of in kernel inotify) will come after the new inotify_user proves to be working correctly. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: handle filesystem unmounts with fsnotify marksEric Paris2009-06-11
| | | | | | | | | | When an fs is unmounted with an fsnotify mark entry attached to one of its inodes we need to destroy that mark entry and we also (like inotify) send an unmount event. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: allow groups to add private data to eventsEric Paris2009-06-11
| | | | | | | | | | inotify needs per group information attached to events. This patch allows groups to attach private information and implements a callback so that information can be freed when an event is being destroyed. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: add correlations between eventsEric Paris2009-06-11
| | | | | | | | | | | 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>
* fsnotify: include pathnames with entries when possibleEric Paris2009-06-11
| | | | | | | | | | 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>
* fsnotify: generic notification queue and waitqEric Paris2009-06-11
| | | | | | | | | | | inotify needs to do asyc notification in which event information is stored on a queue until the listener is ready to receive it. This patch implements a generic notification queue for inotify (and later fanotify) to store events to be sent at a later time. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* dnotify: reimplement dnotify using fsnotifyEric Paris2009-06-11
| | | | | | | | Reimplement dnotify using fsnotify. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
* fsnotify: parent event notificationEric Paris2009-06-11
| | | | | | | | | | | 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>
* fsnotify: add marks to inodes so groups can interpret how to handle those inodesEric Paris2009-06-11
| | | | | | | | | | | | | | | | | 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>
* fsnotify: unified filesystem notification backendEric Paris2009-06-11
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>