2201cde0de
[ Upstream commit 5b8fea65d197f408bb00b251c70d842826d6b70b ] fanotify has some hardcoded limits. The only APIs to escape those limits are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS. Allow finer grained tuning of the system limits via sysfs tunables under /proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify, with some minor differences. - max_queued_events - global system tunable for group queue size limit. Like the inotify tunable with the same name, it defaults to 16384 and applies on initialization of a new group. - max_user_marks - user ns tunable for marks limit per user. Like the inotify tunable named max_user_watches, on a machine with sufficient RAM and it defaults to 1048576 in init userns and can be further limited per containing user ns. - max_user_groups - user ns tunable for number of groups per user. Like the inotify tunable named max_user_instances, it defaults to 128 in init userns and can be further limited per containing user ns. The slightly different tunable names used for fanotify are derived from the "group" and "mark" terminology used in the fanotify man pages and throughout the code. Considering the fact that the default value for max_user_instances was increased in kernel v5.10 from 8192 to 1048576, leaving the legacy fanotify limit of 8192 marks per group in addition to the max_user_marks limit makes little sense, so the per group marks limit has been removed. Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own marks are not accounted in the per user marks account, so in effect the limit of max_user_marks is only for the collection of groups that are not initialized with FAN_UNLIMITED_MARKS. Link: https://lore.kernel.org/r/20210304112921.3996419-2-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> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
88 lines
2.8 KiB
C
Executable file
88 lines
2.8 KiB
C
Executable file
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_FANOTIFY_H
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#define _LINUX_FANOTIFY_H
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#include <linux/sysctl.h>
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#include <uapi/linux/fanotify.h>
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extern struct ctl_table fanotify_table[]; /* for sysctl */
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#define FAN_GROUP_FLAG(group, flag) \
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((group)->fanotify_data.flags & (flag))
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/*
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* Flags allowed to be passed from/to userspace.
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*
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* We intentionally do not add new bits to the old FAN_ALL_* constants, because
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* they are uapi exposed constants. If there are programs out there using
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* these constant, the programs may break if re-compiled with new uapi headers
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* and then run on an old kernel.
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*/
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#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
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FAN_CLASS_PRE_CONTENT)
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#define FANOTIFY_FID_BITS (FAN_REPORT_FID | FAN_REPORT_DFID_NAME)
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#define FANOTIFY_INIT_FLAGS (FANOTIFY_CLASS_BITS | FANOTIFY_FID_BITS | \
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FAN_REPORT_TID | \
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FAN_CLOEXEC | FAN_NONBLOCK | \
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FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
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#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
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FAN_MARK_FILESYSTEM)
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#define FANOTIFY_MARK_FLAGS (FANOTIFY_MARK_TYPE_BITS | \
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FAN_MARK_ADD | \
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FAN_MARK_REMOVE | \
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FAN_MARK_DONT_FOLLOW | \
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FAN_MARK_ONLYDIR | \
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FAN_MARK_IGNORED_MASK | \
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FAN_MARK_IGNORED_SURV_MODIFY | \
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FAN_MARK_FLUSH)
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/*
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* Events that can be reported with data type FSNOTIFY_EVENT_PATH.
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* Note that FAN_MODIFY can also be reported with data type
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* FSNOTIFY_EVENT_INODE.
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*/
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#define FANOTIFY_PATH_EVENTS (FAN_ACCESS | FAN_MODIFY | \
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FAN_CLOSE | FAN_OPEN | FAN_OPEN_EXEC)
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/*
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* Directory entry modification events - reported only to directory
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* where entry is modified and not to a watching parent.
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*/
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#define FANOTIFY_DIRENT_EVENTS (FAN_MOVE | FAN_CREATE | FAN_DELETE)
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/* Events that can only be reported with data type FSNOTIFY_EVENT_INODE */
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#define FANOTIFY_INODE_EVENTS (FANOTIFY_DIRENT_EVENTS | \
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FAN_ATTRIB | FAN_MOVE_SELF | FAN_DELETE_SELF)
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/* Events that user can request to be notified on */
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#define FANOTIFY_EVENTS (FANOTIFY_PATH_EVENTS | \
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FANOTIFY_INODE_EVENTS)
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/* Events that require a permission response from user */
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#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \
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FAN_OPEN_EXEC_PERM)
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/* Extra flags that may be reported with event or control handling of events */
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#define FANOTIFY_EVENT_FLAGS (FAN_EVENT_ON_CHILD | FAN_ONDIR)
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/* Events that may be reported to user */
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#define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENTS | \
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FANOTIFY_PERM_EVENTS | \
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FAN_Q_OVERFLOW | FAN_ONDIR)
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#define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \
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FANOTIFY_EVENT_FLAGS)
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/* Do not use these old uapi constants internally */
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#undef FAN_ALL_CLASS_BITS
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#undef FAN_ALL_INIT_FLAGS
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#undef FAN_ALL_MARK_FLAGS
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#undef FAN_ALL_EVENTS
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#undef FAN_ALL_PERM_EVENTS
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#undef FAN_ALL_OUTGOING_EVENTS
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#endif /* _LINUX_FANOTIFY_H */
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