diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig index dffbb0911d02..22c629eedd82 100644 --- a/fs/notify/Kconfig +++ b/fs/notify/Kconfig @@ -3,3 +3,4 @@ config FSNOTIFY source "fs/notify/dnotify/Kconfig" source "fs/notify/inotify/Kconfig" +source "fs/notify/fanotify/Kconfig" diff --git a/fs/notify/Makefile b/fs/notify/Makefile index 0922cc826c46..396a38779371 100644 --- a/fs/notify/Makefile +++ b/fs/notify/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o obj-y += dnotify/ obj-y += inotify/ +obj-y += fanotify/ diff --git a/fs/notify/fanotify/Kconfig b/fs/notify/fanotify/Kconfig new file mode 100644 index 000000000000..f9d7ae081f85 --- /dev/null +++ b/fs/notify/fanotify/Kconfig @@ -0,0 +1,11 @@ +config FANOTIFY + bool "Filesystem wide access notification" + select FSNOTIFY + default y + ---help--- + Say Y here to enable fanotify suport. fanotify is a file access + notification system which differs from inotify in that it sends + and open file descriptor to the userspace listener along with + the event. + + If unsure, say Y. diff --git a/fs/notify/fanotify/Makefile b/fs/notify/fanotify/Makefile new file mode 100644 index 000000000000..e7d39c05b0fe --- /dev/null +++ b/fs/notify/fanotify/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_FANOTIFY) += fanotify.o diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c new file mode 100644 index 000000000000..3ffb9dbcab08 --- /dev/null +++ b/fs/notify/fanotify/fanotify.c @@ -0,0 +1,78 @@ +#include +#include +#include +#include /* UINT_MAX */ +#include + +#include "fanotify.h" + +static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event) +{ + int ret; + + + BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); + BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); + BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE); + BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE); + BUILD_BUG_ON(FAN_OPEN != FS_OPEN); + BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD); + BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW); + + pr_debug("%s: group=%p event=%p\n", __func__, group, event); + + ret = fsnotify_add_notify_event(group, event, NULL, NULL); + + return ret; +} + +static bool fanotify_should_send_event(struct fsnotify_group *group, struct inode *inode, + struct vfsmount *mnt, __u32 mask, void *data, + int data_type) +{ + struct fsnotify_mark *fsn_mark; + bool send; + + pr_debug("%s: group=%p inode=%p mask=%x data=%p data_type=%d\n", + __func__, group, inode, mask, data, data_type); + + /* sorry, fanotify only gives a damn about files and dirs */ + if (!S_ISREG(inode->i_mode) && + !S_ISDIR(inode->i_mode)) + return false; + + /* if we don't have enough info to send an event to userspace say no */ + if (data_type != FSNOTIFY_EVENT_PATH) + return false; + + fsn_mark = fsnotify_find_mark(group, inode); + if (!fsn_mark) + return false; + + /* if the event is for a child and this inode doesn't care about + * events on the child, don't send it! */ + if ((mask & FS_EVENT_ON_CHILD) && + !(fsn_mark->mask & FS_EVENT_ON_CHILD)) { + send = false; + } else { + /* + * We care about children, but do we care about this particular + * type of event? + */ + mask = (mask & ~FS_EVENT_ON_CHILD); + send = (fsn_mark->mask & mask); + } + + /* find took a reference */ + fsnotify_put_mark(fsn_mark); + + return send; +} + +const struct fsnotify_ops fanotify_fsnotify_ops = { + .handle_event = fanotify_handle_event, + .should_send_event = fanotify_should_send_event, + .free_group_priv = NULL, + .free_event_priv = NULL, + .freeing_mark = NULL, +}; diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h new file mode 100644 index 000000000000..50765eb30fe4 --- /dev/null +++ b/fs/notify/fanotify/fanotify.h @@ -0,0 +1,12 @@ +#include +#include +#include +#include +#include + +static inline bool fanotify_mask_valid(__u32 mask) +{ + if (mask & ~((__u32)FAN_ALL_INCOMING_EVENTS)) + return false; + return true; +} diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 2fc8e14cc24a..d5cca9a05f14 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -210,6 +210,7 @@ unifdef-y += ethtool.h unifdef-y += eventpoll.h unifdef-y += signalfd.h unifdef-y += ext2_fs.h +unifdef-y += fanotify.h unifdef-y += fb.h unifdef-y += fcntl.h unifdef-y += filter.h diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h new file mode 100644 index 000000000000..b560f86d1401 --- /dev/null +++ b/include/linux/fanotify.h @@ -0,0 +1,40 @@ +#ifndef _LINUX_FANOTIFY_H +#define _LINUX_FANOTIFY_H + +#include + +/* the following events that user-space can register for */ +#define FAN_ACCESS 0x00000001 /* File was accessed */ +#define FAN_MODIFY 0x00000002 /* File was modified */ +#define FAN_CLOSE_WRITE 0x00000008 /* Unwrittable file closed */ +#define FAN_CLOSE_NOWRITE 0x00000010 /* Writtable file closed */ +#define FAN_OPEN 0x00000020 /* File was opened */ + +#define FAN_EVENT_ON_CHILD 0x08000000 /* interested in child events */ + +/* FIXME currently Q's have no limit.... */ +#define FAN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ + +/* helper events */ +#define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */ + +/* + * All of the events - we build the list by hand so that we can add flags in + * the future and not break backward compatibility. Apps will get only the + * events that they originally wanted. Be sure to add new events here! + */ +#define FAN_ALL_EVENTS (FAN_ACCESS |\ + FAN_MODIFY |\ + FAN_CLOSE |\ + FAN_OPEN) + +/* + * All legal FAN bits userspace can request (although possibly not all + * at the same time. + */ +#define FAN_ALL_INCOMING_EVENTS (FAN_ALL_EVENTS |\ + FAN_EVENT_ON_CHILD) +#ifdef __KERNEL__ + +#endif /* __KERNEL__ */ +#endif /* _LINUX_FANOTIFY_H */