| Message ID | 156173701358.15650.8735203424342507015.stgit@warthog.procyon.org.uk |
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David Howells <dhowells@redhat.com> wrote: > The patches can be found here also: > > http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=notifications Actually, that should be: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=notifications-mount David
Here's a set of patches to adds VFS-related watches to the general notification system to add sources of events for: (1) Mount topology events, such as mounting, unmounting, mount expiry, mount reconfiguration. (2) Superblock events, such as R/W<->R/O changes, quota overrun and I/O errors (not complete yet). One of the reasons for this is so that we can remove the issue of processes having to repeatedly and regularly scan /proc/mounts, which has proven to be a system performance problem. To further aid this, the fsinfo() syscall on which this patch series depends, provides a way to access superblock and mount information in binary form without the need to parse /proc/mounts. LSM hooks are included are provided that allow an LSM to rule on whether or not a watch may be set. Each of these hooks takes a different "watched object" parameter, so they're not really shareable. The LSM should use current's credentials. [Wanted by SELinux & Smack] Watches are created with: watch_mount(AT_FDCWD, "/", 0, fd, 0x03); watch_sb(AT_FDCWD, "/mnt", 0, fd, 0x04); where in all three cases, fd indicates the queue and the number after is a tag between 0 and 255. Further things that could be considered: (1) Adding global superblock event queue. (2) Propagating watches to child superblock over automounts. The patches can be found here also: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=notifications Changes: ver #5: (*) The superblock watch and mount watch parts are split out into this set from the core branch (notifications-core) as it depends on fsinfo(). David --- David Howells (6): security: Add hooks to rule on setting a superblock or mount watch Adjust watch_queue documentation to mention mount and superblock watches. vfs: Add a mount-notification facility vfs: Add superblock notifications fsinfo: Export superblock notification counter Add sample notification program Documentation/watch_queue.rst | 20 +++ arch/alpha/kernel/syscalls/syscall.tbl | 2 arch/arm/tools/syscall.tbl | 2 arch/arm64/include/asm/unistd.h | 2 arch/ia64/kernel/syscalls/syscall.tbl | 2 arch/m68k/kernel/syscalls/syscall.tbl | 2 arch/microblaze/kernel/syscalls/syscall.tbl | 2 arch/mips/kernel/syscalls/syscall_n32.tbl | 2 arch/mips/kernel/syscalls/syscall_n64.tbl | 2 arch/mips/kernel/syscalls/syscall_o32.tbl | 2 arch/parisc/kernel/syscalls/syscall.tbl | 2 arch/powerpc/kernel/syscalls/syscall.tbl | 2 arch/s390/kernel/syscalls/syscall.tbl | 2 arch/sh/kernel/syscalls/syscall.tbl | 2 arch/sparc/kernel/syscalls/syscall.tbl | 2 arch/x86/entry/syscalls/syscall_32.tbl | 2 arch/x86/entry/syscalls/syscall_64.tbl | 2 arch/xtensa/kernel/syscalls/syscall.tbl | 2 drivers/misc/Kconfig | 5 - fs/Kconfig | 21 +++ fs/Makefile | 1 fs/fsinfo.c | 12 ++ fs/mount.h | 33 +++-- fs/mount_notify.c | 188 +++++++++++++++++++++++++++ fs/namespace.c | 16 ++ fs/super.c | 126 ++++++++++++++++++ include/linux/dcache.h | 1 include/linux/fs.h | 78 +++++++++++ include/linux/lsm_hooks.h | 16 ++ include/linux/security.h | 10 + include/linux/syscalls.h | 4 + include/uapi/asm-generic/unistd.h | 6 + include/uapi/linux/fsinfo.h | 10 + include/uapi/linux/watch_queue.h | 61 +++++++++ kernel/sys_ni.c | 2 samples/vfs/test-fsinfo.c | 13 ++ samples/watch_queue/watch_test.c | 76 +++++++++++ security/security.c | 10 + 38 files changed, 722 insertions(+), 21 deletions(-) create mode 100644 fs/mount_notify.c