From 6d98076c15e8726606da0a99714cd3382d82f9ac Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Mon, 3 Apr 2006 06:46:55 +0000 Subject: r14877: added support for the kernel inotify mechanism. This passes basic tests, but still needs some more work to ensure we correctly cope with events that may generate both a system inotify event and a internal notify event. The system inotify events won't handle recursion, and don't understand things like streams. This also adds the ntvfs/sysdep/ directory, which is meant for system dependent code that is not tied to a particular ntvfs backend. The inotify code is a good example of that. (This used to be commit eadadbb44adb3c4081d6ff1d85a9b850a0227059) --- source4/ntvfs/sysdep/inotify.c | 313 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 313 insertions(+) create mode 100644 source4/ntvfs/sysdep/inotify.c (limited to 'source4/ntvfs/sysdep/inotify.c') diff --git a/source4/ntvfs/sysdep/inotify.c b/source4/ntvfs/sysdep/inotify.c new file mode 100644 index 0000000000..31c408d112 --- /dev/null +++ b/source4/ntvfs/sysdep/inotify.c @@ -0,0 +1,313 @@ +/* + Unix SMB/CIFS implementation. + + Copyright (C) Andrew Tridgell 2006 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/* + notify implementation using inotify +*/ + +#include "includes.h" +#include "system/filesys.h" +#include "ntvfs/sysdep/sys_notify.h" +#include "lib/events/events.h" +#include "smb.h" +#include "dlinklist.h" + +#include +#include + +#ifndef HAVE_INOTIFY_INIT +/* + glibc doesn't define these functions yet (as of March 2006) +*/ +static int inotify_init(void) +{ + return syscall(__NR_inotify_init); +} + +static int inotify_add_watch(int fd, const char *path, __u32 mask) +{ + return syscall(__NR_inotify_add_watch, fd, path, mask); +} + +static int inotify_rm_watch(int fd, int wd) +{ + return syscall(__NR_inotify_rm_watch, fd, wd); +} +#endif + + +/* older glibc headers don't have these defines either */ +#ifndef IN_ONLYDIR +#define IN_ONLYDIR 0x01000000 +#endif +#ifndef IN_MASK_ADD +#define IN_MASK_ADD 0x20000000 +#endif + +struct inotify_private { + struct sys_notify_context *ctx; + int fd; + struct watch_context *watches; +}; + +struct watch_context { + struct watch_context *next, *prev; + struct inotify_private *in; + int wd; + sys_notify_callback_t callback; + void *private; + uint32_t mask; +}; + + +/* + destroy the inotify private context +*/ +static int inotify_destructor(void *ptr) +{ + struct inotify_private *in = talloc_get_type(ptr, struct inotify_private); + close(in->fd); + return 0; +} + + +/* + dispatch one inotify event +*/ +static void inotify_dispatch(struct inotify_private *in, struct inotify_event *e) +{ + struct watch_context *w; + struct notify_event ne; + + /* ignore extraneous events, such as unmount and IN_IGNORED events */ + if ((e->mask & (IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO)) == 0) { + return; + } + + /* map the inotify mask to a action */ + if (e->mask & IN_CREATE) { + ne.action = NOTIFY_ACTION_ADDED; + } else if (e->mask & IN_DELETE) { + ne.action = NOTIFY_ACTION_REMOVED; + } else { + ne.action = NOTIFY_ACTION_MODIFIED; + } + ne.path = e->name; + + /* find any watches that have this watch descriptor */ + for (w=in->watches;w;w=w->next) { + /* checking the mask copes with multiple watches */ + if (w->wd == e->wd && (e->mask & w->mask) != 0) { + w->callback(in->ctx, w->private, &ne); + } + } +} + +/* + called when the kernel has some events for us +*/ +static void inotify_handler(struct event_context *ev, struct fd_event *fde, + uint16_t flags, void *private) +{ + struct inotify_private *in = talloc_get_type(private, struct inotify_private); + int bufsize = 0; + struct inotify_event *e0, *e; + + /* + we must use FIONREAD as we cannot predict the length of the + filenames, and thus can't know how much to allocate + otherwise + */ + if (ioctl(in->fd, FIONREAD, &bufsize) != 0 || + bufsize == 0) { + DEBUG(0,("No data on inotify fd?!\n")); + return; + } + + e0 = e = talloc_size(in, bufsize); + if (e == NULL) return; + + if (read(in->fd, e0, bufsize) != bufsize) { + DEBUG(0,("Failed to read all inotify data\n")); + talloc_free(e0); + return; + } + + /* we can get more than one event in the buffer */ + while (bufsize >= sizeof(*e)) { + inotify_dispatch(in, e); + bufsize -= e->len + sizeof(*e); + e = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e); + } + + talloc_free(e0); +} + +/* + setup the inotify handle - called the first time a watch is added on + this context +*/ +static NTSTATUS inotify_setup(struct sys_notify_context *ctx) +{ + struct inotify_private *in; + + in = talloc(ctx, struct inotify_private); + NT_STATUS_HAVE_NO_MEMORY(in); + in->fd = inotify_init(); + if (in->fd == -1) { + DEBUG(0,("Failed to init inotify - %s\n", strerror(errno))); + talloc_free(in); + return map_nt_error_from_unix(errno); + } + in->ctx = ctx; + in->watches = NULL; + + ctx->private = in; + talloc_set_destructor(in, inotify_destructor); + + /* add a event waiting for the inotify fd to be readable */ + event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ, inotify_handler, in); + + return NT_STATUS_OK; +} + + +/* + map from a change notify mask to a inotify mask. Approximate only :( +*/ +static const struct { + uint32_t notify_mask; + uint32_t inotify_mask; +} inotify_mapping[] = { + {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO}, + {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_SIZE, IN_MODIFY}, + {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB} +}; + +static uint32_t inotify_map(uint32_t mask) +{ + int i; + uint32_t out=0; + for (i=0;iin; + int wd = w->wd; + DLIST_REMOVE(w->in->watches, w); + + /* only rm the watch if its the last one with this wd */ + for (w=in->watches;w;w=w->next) { + if (w->wd == wd) break; + } + if (w == NULL) { + inotify_rm_watch(in->fd, wd); + } + return 0; +} + + +/* + add a watch. The watch is removed when the caller calls + talloc_free() on handle +*/ +static NTSTATUS inotify_watch(struct sys_notify_context *ctx, const char *dirpath, + uint32_t filter, sys_notify_callback_t callback, + void *private, void **handle) +{ + struct inotify_private *in; + int wd; + uint32_t mask; + struct watch_context *w; + + /* maybe setup the inotify fd */ + if (ctx->private == NULL) { + NTSTATUS status; + status = inotify_setup(ctx); + NT_STATUS_NOT_OK_RETURN(status); + } + + in = talloc_get_type(ctx->private, struct inotify_private); + + mask = inotify_map(filter); + if (mask == 0) { + /* this filter can't be handled by inotify */ + return NT_STATUS_INVALID_PARAMETER; + } + + /* using IN_MASK_ADD allows us to cope with inotify() returning the same + watch descriptor for muliple watches on the same path */ + mask |= (IN_MASK_ADD | IN_ONLYDIR); + + /* get a new watch descriptor for this path */ + wd = inotify_add_watch(in->fd, dirpath, mask); + if (wd == -1) { + return map_nt_error_from_unix(errno); + } + + w = talloc(in, struct watch_context); + if (w == NULL) { + inotify_rm_watch(in->fd, wd); + return NT_STATUS_NO_MEMORY; + } + + w->in = in; + w->wd = wd; + w->callback = callback; + w->private = private; + w->mask = mask; + + (*handle) = w; + + DLIST_ADD(in->watches, w); + + /* the caller frees the handle to stop watching */ + talloc_set_destructor(w, watch_destructor); + + return NT_STATUS_OK; +} + + +static struct sys_notify_backend inotify = { + .name = "inotify", + .notify_watch = inotify_watch +}; + +/* + initialialise the inotify module + */ +NTSTATUS ntvfs_inotify_init(void) +{ + /* register ourselves as a system inotify module */ + return sys_notify_register(&inotify); +} -- cgit