| Message ID | 20210426184201.4177978-8-krisman@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | File system wide monitoring | expand |
On Mon, Apr 26, 2021 at 9:42 PM Gabriel Krisman Bertazi <krisman@collabora.com> wrote: > > Expose a new type of fsnotify event for filesystems to report errors for > userspace monitoring tools. fanotify will send this type of > notification for FAN_ERROR marks. > > Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> > --- > fs/notify/fsnotify.c | 2 +- > include/linux/fsnotify_backend.h | 16 ++++++++++++++++ > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c > index 30d422b8c0fc..9fff35e67b37 100644 > --- a/fs/notify/fsnotify.c > +++ b/fs/notify/fsnotify.c > @@ -558,7 +558,7 @@ static __init int fsnotify_init(void) > { > int ret; > > - BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25); > + BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 26); > > ret = init_srcu_struct(&fsnotify_mark_srcu); > if (ret) > diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h > index a1a4dd69e5ed..f850bfbe30d4 100644 > --- a/include/linux/fsnotify_backend.h > +++ b/include/linux/fsnotify_backend.h > @@ -48,6 +48,8 @@ > #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ > #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ > > +#define FS_ERROR 0x00100000 /* Used for filesystem error reporting */ > + Why skip 0x00080000? Anyway, event bits are starting to run out so I would prefer that you overload an existing bit used only by inotify/dnotify. FS_IN_IGNORED is completely internal to inotify and there is no need to set it in i_fsnotify_mask at all, so if we remove the bit from the output of inotify_arg_to_mask() no functionality will change and we will be able to overload the event bit for FS_ERROR (see patch below). I also kind of like that FS_ERROR is adjacent to FS_UMOUNT and FS_Q_OVERFLOW :-) Other FS_IN/FS_DN bits may also be reclaimed but it takes a bit more work I have patches for those. Thanks, Amir. diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 98f61b31745a..351517bae716 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -89,10 +89,10 @@ static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg) __u32 mask; /* - * Everything should accept their own ignored and should receive events - * when the inode is unmounted. All directories care about children. + * Everything should receive events when the inode is unmounted. + * All directories care about children. */ - mask = (FS_IN_IGNORED | FS_UNMOUNT); + mask = FS_UNMOUNT; if (S_ISDIR(inode->i_mode)) mask |= FS_EVENT_ON_CHILD; diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 1ce66748a2d2..ecbafb3f36d7 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -42,6 +42,11 @@ #define FS_UNMOUNT 0x00002000 /* inode on umount fs */ #define FS_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ +#define FS_ERROR 0x00008000 /* Filesystem error report */ +/* + * FS_IN_IGNORED overloads FS_ERROR. It is only used internally by inotify + * which does not support FS_ERROR. + */ #define FS_IN_IGNORED 0x00008000 /* last inotify event here */
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 30d422b8c0fc..9fff35e67b37 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -558,7 +558,7 @@ static __init int fsnotify_init(void) { int ret; - BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 25); + BUILD_BUG_ON(HWEIGHT32(ALL_FSNOTIFY_BITS) != 26); ret = init_srcu_struct(&fsnotify_mark_srcu); if (ret) diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index a1a4dd69e5ed..f850bfbe30d4 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -48,6 +48,8 @@ #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ #define FS_OPEN_EXEC_PERM 0x00040000 /* open/exec event in a permission hook */ +#define FS_ERROR 0x00100000 /* Used for filesystem error reporting */ + #define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ /* * Set on inode mark that cares about things that happen to its children. @@ -74,6 +76,8 @@ #define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM | \ FS_OPEN_EXEC_PERM) +#define ALL_FSNOTIFY_ERROR_EVENTS FS_ERROR + #define FSN_SUBMISSION_RING_BUFFER 0x00000080 /* @@ -95,6 +99,7 @@ /* Events that can be reported to backends */ #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ + ALL_FSNOTIFY_ERROR_EVENTS | \ FS_EVENTS_POSS_ON_CHILD | \ FS_DELETE_SELF | FS_MOVE_SELF | FS_DN_RENAME | \ FS_UNMOUNT | FS_Q_OVERFLOW | FS_IN_IGNORED) @@ -272,6 +277,17 @@ enum fsnotify_data_type { FSNOTIFY_EVENT_NONE, FSNOTIFY_EVENT_PATH, FSNOTIFY_EVENT_INODE, + FSNOTIFY_EVENT_ERROR, +}; + +struct fs_error_report { + int error; + + int line; + const char *function; + + size_t fs_data_size; + void *fs_data; }; static inline struct inode *fsnotify_data_inode(const void *data, int data_type)
Expose a new type of fsnotify event for filesystems to report errors for userspace monitoring tools. fanotify will send this type of notification for FAN_ERROR marks. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> --- fs/notify/fsnotify.c | 2 +- include/linux/fsnotify_backend.h | 16 ++++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-)