diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2024-11-15 10:30:20 -0500 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2024-12-10 12:03:17 +0100 |
| commit | f156524e5d72c81792eee81f828784dc8a37a7f2 (patch) | |
| tree | 3d9c670511c063777307a56b5a3da5d27c4df2b5 /include/linux/fsnotify_backend.h | |
| parent | 0a076036b631f086a6bce93a45eaa216f234f121 (diff) | |
fsnotify: introduce pre-content permission events
The new FS_PRE_ACCESS permission event is similar to FS_ACCESS_PERM,
but it meant for a different use case of filling file content before
access to a file range, so it has slightly different semantics.
Generate FS_PRE_ACCESS/FS_ACCESS_PERM as two seperate events, so content
scanners could inspect the content filled by pre-content event handler.
Unlike FS_ACCESS_PERM, FS_PRE_ACCESS is also called before a file is
modified by syscalls as write() and fallocate().
FS_ACCESS_PERM is reported also on blockdev and pipes, but the new
pre-content events are only reported for regular files and dirs.
The pre-content events are meant to be used by hierarchical storage
managers that want to fill the content of files on first access.
There are some specific requirements from filesystems that could
be used with pre-content events, so add a flag for fs to opt-in
for pre-content events explicitly before they can be used.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/b934c5e3af205abc4e0e4709f6486815937ddfdf.1731684329.git.josef@toxicpanda.com
Diffstat (limited to 'include/linux/fsnotify_backend.h')
| -rw-r--r-- | include/linux/fsnotify_backend.h | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index c38762b62bf1..9bda354b5538 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -57,6 +57,8 @@ #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ /* #define FS_DIR_MODIFY 0x00080000 */ /* Deprecated (reserved) */ +#define FS_PRE_ACCESS 0x00100000 /* Pre-content access hook */ + /* * Set on inode mark that cares about things that happen to its children. * Always set for dnotify and inotify. @@ -78,11 +80,14 @@ */ #define ALL_FSNOTIFY_DIRENT_EVENTS (FS_CREATE | FS_DELETE | FS_MOVE | FS_RENAME) +/* Content events can be used to inspect file content */ +#define FSNOTIFY_CONTENT_PERM_EVENTS (FS_OPEN_PERM | FS_OPEN_EXEC_PERM | \ + FS_ACCESS_PERM) /* Pre-content events can be used to fill file content */ -#define FSNOTIFY_PRE_CONTENT_EVENTS 0 +#define FSNOTIFY_PRE_CONTENT_EVENTS (FS_PRE_ACCESS) -#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ - FS_OPEN_EXEC_PERM) +#define ALL_FSNOTIFY_PERM_EVENTS (FSNOTIFY_CONTENT_PERM_EVENTS | \ + FSNOTIFY_PRE_CONTENT_EVENTS) /* * This is a list of all events that may get sent to a parent that is watching |