From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760855AbZCPHbf (ORCPT ); Mon, 16 Mar 2009 03:31:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755773AbZCPHYI (ORCPT ); Mon, 16 Mar 2009 03:24:08 -0400 Received: from vsmtp01.dti.ne.jp ([202.216.231.136]:35684 "EHLO vsmtp01.dti.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757100AbZCPHXB (ORCPT ); Mon, 16 Mar 2009 03:23:01 -0400 From: "J. R. Okajima" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, "J. R. Okajima" Subject: [RFC Aufs2 #2 23/28] aufs internal inotify Date: Mon, 16 Mar 2009 16:20:35 +0900 Message-Id: <1237188040-11404-24-git-send-email-hooanon05@yahoo.co.jp> X-Mailer: git-send-email 1.6.1.284.g5dc13 In-Reply-To: <1237188040-11404-1-git-send-email-hooanon05@yahoo.co.jp> References: <1237188040-11404-1-git-send-email-hooanon05@yahoo.co.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org initial commit detect bypassing aufs by inotify-watch Signed-off-by: J. R. Okajima --- fs/aufs/hinotify.c | 746 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 746 insertions(+), 0 deletions(-) create mode 100644 fs/aufs/hinotify.c diff --git a/fs/aufs/hinotify.c b/fs/aufs/hinotify.c new file mode 100644 index 0000000..af8ebdb --- /dev/null +++ b/fs/aufs/hinotify.c @@ -0,0 +1,746 @@ +/* + * Copyright (C) 2005-2009 Junjiro R. Okajima + * + * This program, aufs 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. + */ + +/* + * inotify for the lower directories + */ + +#include "aufs.h" + +static const __u32 AuHinMask = (IN_MOVE | IN_DELETE | IN_CREATE); +static struct inotify_handle *au_hin_handle; + +AuCacheFuncs(hinotify, HINOTIFY); + +int au_hin_alloc(struct au_hinode *hinode, struct inode *inode, + struct inode *h_inode) +{ + int err; + struct au_hinotify *hin; + s32 wd; + + err = -ENOMEM; + hin = au_cache_alloc_hinotify(); + if (hin) { + AuDebugOn(hinode->hi_notify); + hinode->hi_notify = hin; + hin->hin_aufs_inode = inode; + + inotify_init_watch(&hin->hin_watch); + wd = inotify_add_watch(au_hin_handle, &hin->hin_watch, h_inode, + AuHinMask); + if (wd >= 0) + return 0; /* success */ + + err = wd; + put_inotify_watch(&hin->hin_watch); + au_cache_free_hinotify(hin); + hinode->hi_notify = NULL; + } + + return err; +} + +void au_hin_free(struct au_hinode *hinode) +{ + int err; + struct au_hinotify *hin; + + hin = hinode->hi_notify; + if (hin) { + err = 0; + if (atomic_read(&hin->hin_watch.count)) + err = inotify_rm_watch(au_hin_handle, &hin->hin_watch); + if (unlikely(err)) + /* it means the watch is already removed */ + AuWarn("failed inotify_rm_watch() %d\n", err); + au_cache_free_hinotify(hin); + hinode->hi_notify = NULL; + } +} + +/* ---------------------------------------------------------------------- */ + +void au_hin_ctl(struct au_hinode *hinode, int do_set) +{ + struct inode *h_inode; + struct inotify_watch *watch; + + if (!hinode->hi_notify) + return; + + h_inode = hinode->hi_inode; + IMustLock(h_inode); + + /* todo: try inotify_find_update_watch()? */ + watch = &hinode->hi_notify->hin_watch; + mutex_lock(&h_inode->inotify_mutex); + /* mutex_lock(&watch->ih->mutex); */ + if (do_set) { + AuDebugOn(watch->mask & AuHinMask); + watch->mask |= AuHinMask; + } else { + AuDebugOn(!(watch->mask & AuHinMask)); + watch->mask &= ~AuHinMask; + } + /* mutex_unlock(&watch->ih->mutex); */ + mutex_unlock(&h_inode->inotify_mutex); +} + +void au_reset_hinotify(struct inode *inode, unsigned int flags) +{ + aufs_bindex_t bindex, bend; + struct inode *hi; + struct dentry *iwhdentry; + + bend = au_ibend(inode); + for (bindex = au_ibstart(inode); bindex <= bend; bindex++) { + hi = au_h_iptr(inode, bindex); + if (!hi) + continue; + + /* mutex_lock_nested(&hi->i_mutex, AuLsc_I_CHILD); */ + iwhdentry = au_hi_wh(inode, bindex); + if (iwhdentry) + dget(iwhdentry); + au_igrab(hi); + au_set_h_iptr(inode, bindex, NULL, 0); + au_set_h_iptr(inode, bindex, au_igrab(hi), + flags & ~AuHi_XINO); + iput(hi); + dput(iwhdentry); + /* mutex_unlock(&hi->i_mutex); */ + } +} + +/* ---------------------------------------------------------------------- */ + +static int hin_xino(struct inode *inode, struct inode *h_inode) +{ + int err; + aufs_bindex_t bindex, bend, bfound, bstart; + struct inode *h_i; + + err = 0; + if (unlikely(inode->i_ino == AUFS_ROOT_INO)) { + AuWarn("branch root dir was changed\n"); + goto out; + } + + bfound = -1; + bend = au_ibend(inode); + bstart = au_ibstart(inode); +#if 0 /* reserved for future use */ + if (bindex == bend) { + /* keep this ino in rename case */ + goto out; + } +#endif + for (bindex = bstart; bindex <= bend; bindex++) { + if (au_h_iptr(inode, bindex) == h_inode) { + bfound = bindex; + break; + } + } + if (bfound < 0) + goto out; + + for (bindex = bstart; bindex <= bend; bindex++) { + h_i = au_h_iptr(inode, bindex); + if (!h_i) + continue; + + err = au_xino_write0(inode->i_sb, bindex, h_i->i_ino, 0); + /* ignore this error */ + /* bad action? */ + } + + /* children inode number will be broken */ + + out: + AuTraceErr(err); + return err; +} + +static int hin_gen_tree(struct dentry *dentry) +{ + int err, i, j, ndentry; + struct au_dcsub_pages dpages; + struct au_dpage *dpage; + struct dentry **dentries; + + err = au_dpages_init(&dpages, GFP_NOFS); + if (unlikely(err)) + goto out; + err = au_dcsub_pages(&dpages, dentry, NULL, NULL); + if (unlikely(err)) + goto out_dpages; + + for (i = 0; i < dpages.ndpage; i++) { + dpage = dpages.dpages + i; + dentries = dpage->dentries; + ndentry = dpage->ndentry; + for (j = 0; j < ndentry; j++) { + struct dentry *d; + + d = dentries[j]; + if (IS_ROOT(d)) + continue; + + d_drop(d); + au_digen_dec(d); + if (d->d_inode) + /* todo: reset children xino? + cached children only? */ + au_iigen_dec(d->d_inode); + } + } + + out_dpages: + au_dpages_free(&dpages); + + /* discard children */ + dentry_unhash(dentry); + dput(dentry); + out: + return err; +} + +/* + * return 0 if processed. + */ +static int hin_gen_by_inode(char *name, unsigned int nlen, struct inode *inode, + const unsigned int isdir) +{ + int err; + struct dentry *d; + struct qstr *dname; + + err = 1; + if (unlikely(inode->i_ino == AUFS_ROOT_INO)) { + AuWarn("branch root dir was changed\n"); + err = 0; + goto out; + } + + if (!isdir) { + AuDebugOn(!name); + au_iigen_dec(inode); + spin_lock(&dcache_lock); + list_for_each_entry(d, &inode->i_dentry, d_alias) { + dname = &d->d_name; + if (dname->len != nlen + && memcmp(dname->name, name, nlen)) + continue; + err = 0; + spin_lock(&d->d_lock); + __d_drop(d); + au_digen_dec(d); + spin_unlock(&d->d_lock); + break; + } + spin_unlock(&dcache_lock); + } else { + au_fset_si(au_sbi(inode->i_sb), FAILED_REFRESH_DIRS); + d = d_find_alias(inode); + if (!d) { + au_iigen_dec(inode); + goto out; + } + + dname = &d->d_name; + if (dname->len == nlen && !memcmp(dname->name, name, nlen)) + err = hin_gen_tree(d); + dput(d); + } + + out: + AuTraceErr(err); + return err; +} + +static int hin_gen_by_name(struct dentry *dentry, const unsigned int isdir) +{ + int err; + struct inode *inode; + + inode = dentry->d_inode; + if (IS_ROOT(dentry) + /* || (inode && inode->i_ino == AUFS_ROOT_INO) */ + ) { + AuWarn("branch root dir was changed\n"); + return 0; + } + + err = 0; + if (!isdir) { + d_drop(dentry); + au_digen_dec(dentry); + if (inode) + au_iigen_dec(inode); + } else { + au_fset_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS); + if (inode) + err = hin_gen_tree(dentry); + } + + AuTraceErr(err); + return err; +} + +/* ---------------------------------------------------------------------- */ + +/* hinotify job flags */ +#define AuHinJob_XINO0 1 +#define AuHinJob_GEN (1 << 1) +#define AuHinJob_DIRENT (1 << 2) +#define AuHinJob_ISDIR (1 << 3) +#define AuHinJob_TRYXINO0 (1 << 4) +#define AuHinJob_MNTPNT (1 << 5) +#define au_ftest_hinjob(flags, name) ((flags) & AuHinJob_##name) +#define au_fset_hinjob(flags, name) { (flags) |= AuHinJob_##name; } +#define au_fclr_hinjob(flags, name) { (flags) &= ~AuHinJob_##name; } + +struct hin_job_args { + unsigned int flags; + struct inode *inode, *h_inode, *dir, *h_dir; + struct dentry *dentry; + char *h_name; + int h_nlen; +}; + +static int hin_job(struct hin_job_args *a) +{ + const unsigned int isdir = au_ftest_hinjob(a->flags, ISDIR); + + /* reset xino */ + if (au_ftest_hinjob(a->flags, XINO0) && a->inode) + hin_xino(a->inode, a->h_inode); /* ignore this error */ + + if (au_ftest_hinjob(a->flags, TRYXINO0) + && a->inode + && a->h_inode) { + mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD); + if (!a->h_inode->i_nlink) + hin_xino(a->inode, a->h_inode); /* ignore this error */ + mutex_unlock(&a->h_inode->i_mutex); + } + + /* make the generation obsolete */ + if (au_ftest_hinjob(a->flags, GEN)) { + int err = -1; + if (a->inode) + err = hin_gen_by_inode(a->h_name, a->h_nlen, a->inode, + isdir); + if (err && a->dentry) + hin_gen_by_name(a->dentry, isdir); + /* ignore this error */ + } + + /* make dir entries obsolete */ + if (au_ftest_hinjob(a->flags, DIRENT) && a->inode) { + struct au_vdir *vdir; + + vdir = au_ivdir(a->inode); + if (vdir) + vdir->vd_jiffy = 0; + /* IMustLock(a->inode); */ + /* a->inode->i_version++; */ + } + + /* can do nothing but warn */ + if (au_ftest_hinjob(a->flags, MNTPNT) + && a->dentry + && d_mountpoint(a->dentry)) + AuWarn("mount-point %.*s is removed or renamed\n", + AuDLNPair(a->dentry)); + + return 0; +} + +/* ---------------------------------------------------------------------- */ + +static char *in_name(u32 mask) +{ +#ifdef CONFIG_AUFS_DEBUG +#define test_ret(flag) if (mask & flag) \ + return #flag; + test_ret(IN_ACCESS); + test_ret(IN_MODIFY); + test_ret(IN_ATTRIB); + test_ret(IN_CLOSE_WRITE); + test_ret(IN_CLOSE_NOWRITE); + test_ret(IN_OPEN); + test_ret(IN_MOVED_FROM); + test_ret(IN_MOVED_TO); + test_ret(IN_CREATE); + test_ret(IN_DELETE); + test_ret(IN_DELETE_SELF); + test_ret(IN_MOVE_SELF); + test_ret(IN_UNMOUNT); + test_ret(IN_Q_OVERFLOW); + test_ret(IN_IGNORED); + return ""; +#undef test_ret +#else + return "??"; +#endif +} + +static struct dentry *lookup_wlock_by_name(char *name, unsigned int nlen, + struct inode *dir) +{ + struct dentry *dentry, *d, *parent; + struct qstr *dname; + + parent = d_find_alias(dir); + if (!parent) + return NULL; + + dentry = NULL; + spin_lock(&dcache_lock); + list_for_each_entry(d, &parent->d_subdirs, d_u.d_child) { + /* AuDbg("%.*s\n", AuDLNPair(d)); */ + dname = &d->d_name; + if (dname->len != nlen || memcmp(dname->name, name, nlen)) + continue; + if (!atomic_read(&d->d_count) || !d->d_fsdata) { + spin_lock(&d->d_lock); + __d_drop(d); + spin_unlock(&d->d_lock); + continue; + } + + dentry = dget(d); + break; + } + spin_unlock(&dcache_lock); + dput(parent); + + if (dentry) + di_write_lock_child(dentry); + + return dentry; +} + +static struct inode *lookup_wlock_by_ino(struct super_block *sb, + aufs_bindex_t bindex, ino_t h_ino) +{ + struct inode *inode; + ino_t ino; + int err; + + inode = NULL; + err = au_xino_read(sb, bindex, h_ino, &ino); + if (!err && ino) + inode = ilookup(sb, ino); + if (!inode) + goto out; + + if (unlikely(inode->i_ino == AUFS_ROOT_INO)) { + AuWarn("wrong root branch\n"); + iput(inode); + inode = NULL; + goto out; + } + + ii_write_lock_child(inode); + + out: + return inode; +} + +enum { CHILD, PARENT }; +struct postproc_args { + struct inode *h_dir, *dir, *h_child_inode; + u32 mask; + unsigned int flags[2]; + unsigned int h_child_nlen; + char h_child_name[]; +}; + +static void postproc(void *_args) +{ + struct postproc_args *a = _args; + struct super_block *sb; + aufs_bindex_t bindex, bend, bfound; + unsigned char xino, try_iput; + int err; + struct inode *inode; + ino_t h_ino; + struct hin_job_args args; + struct dentry *dentry; + struct au_sbinfo *sbinfo; + + AuDebugOn(!_args); + AuDebugOn(!a->h_dir); + AuDebugOn(!a->dir); + AuDebugOn(!a->mask); + AuDbg("mask 0x%x %s, i%lu, hi%lu, hci%lu\n", + a->mask, in_name(a->mask), a->dir->i_ino, a->h_dir->i_ino, + a->h_child_inode ? a->h_child_inode->i_ino : 0); + + inode = NULL; + dentry = NULL; + /* + * do not lock a->dir->i_mutex here + * because of d_revalidate() may cause a deadlock. + */ + sb = a->dir->i_sb; + AuDebugOn(!sb); + sbinfo = au_sbi(sb); + AuDebugOn(!sbinfo); + /* big aufs lock */ + si_noflush_write_lock(sb); + + ii_read_lock_parent(a->dir); + bfound = -1; + bend = au_ibend(a->dir); + for (bindex = au_ibstart(a->dir); bindex <= bend; bindex++) + if (au_h_iptr(a->dir, bindex) == a->h_dir) { + bfound = bindex; + break; + } + ii_read_unlock(a->dir); + if (unlikely(bfound < 0)) + goto out; + + xino = !!au_opt_test(au_mntflags(sb), XINO); + h_ino = 0; + if (a->h_child_inode) + h_ino = a->h_child_inode->i_ino; + + if (a->h_child_nlen + && (au_ftest_hinjob(a->flags[CHILD], GEN) + || au_ftest_hinjob(a->flags[CHILD], MNTPNT))) + dentry = lookup_wlock_by_name(a->h_child_name, a->h_child_nlen, + a->dir); + try_iput = 0; + if (dentry) + inode = dentry->d_inode; + if (xino && !inode && h_ino + && (au_ftest_hinjob(a->flags[CHILD], XINO0) + || au_ftest_hinjob(a->flags[CHILD], TRYXINO0) + || au_ftest_hinjob(a->flags[CHILD], GEN))) { + inode = lookup_wlock_by_ino(sb, bfound, h_ino); + try_iput = 1; + } + + args.flags = a->flags[CHILD]; + args.dentry = dentry; + args.inode = inode; + args.h_inode = a->h_child_inode; + args.dir = a->dir; + args.h_dir = a->h_dir; + args.h_name = a->h_child_name; + args.h_nlen = a->h_child_nlen; + err = hin_job(&args); + if (dentry) { + if (dentry->d_fsdata) + di_write_unlock(dentry); + dput(dentry); + } + if (inode && try_iput) { + ii_write_unlock(inode); + iput(inode); + } + + ii_write_lock_parent(a->dir); + args.flags = a->flags[PARENT]; + args.dentry = NULL; + args.inode = a->dir; + args.h_inode = a->h_dir; + args.dir = NULL; + args.h_dir = NULL; + args.h_name = NULL; + args.h_nlen = 0; + err = hin_job(&args); + ii_write_unlock(a->dir); + + out: + au_nwt_done(&sbinfo->si_nowait); + si_write_unlock(sb); + + iput(a->h_child_inode); + iput(a->h_dir); + iput(a->dir); + kfree(a); +} + +/* ---------------------------------------------------------------------- */ + +static void aufs_inotify(struct inotify_watch *watch, u32 wd __maybe_unused, + u32 mask, u32 cookie __maybe_unused, + const char *h_child_name, struct inode *h_child_inode) +{ + struct au_hinotify *hinotify; + struct postproc_args *args; + int len, wkq_err; + unsigned char isdir, isroot, wh; + char *p; + struct inode *dir; + unsigned int flags[2]; + + /* if IN_UNMOUNT happens, there must be another bug */ + AuDebugOn(mask & IN_UNMOUNT); + if (mask & (IN_IGNORED | IN_UNMOUNT)) { + put_inotify_watch(watch); + return; + } +#ifdef AuDbgHinotify + au_debug(1); + if (1 || !h_child_name || strcmp(h_child_name, AUFS_XINO_FNAME)) { + AuDbg("i%lu, wd %d, mask 0x%x %s, cookie 0x%x, hcname %s," + " hi%lu\n", + watch->inode->i_ino, wd, mask, in_name(mask), cookie, + h_child_name ? h_child_name : "", + h_child_inode ? h_child_inode->i_ino : 0); + WARN_ON(1); + } + au_debug(0); +#endif + + hinotify = container_of(watch, struct au_hinotify, hin_watch); + AuDebugOn(!hinotify || !hinotify->hin_aufs_inode); + dir = igrab(hinotify->hin_aufs_inode); + if (!dir) + return; + + isroot = (dir->i_ino == AUFS_ROOT_INO); + len = 0; + wh = 0; + if (h_child_name) { + len = strlen(h_child_name); + if (!memcmp(h_child_name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) { + h_child_name += AUFS_WH_PFX_LEN; + len -= AUFS_WH_PFX_LEN; + wh = 1; + } + } + + isdir = 0; + if (h_child_inode) + isdir = !!S_ISDIR(h_child_inode->i_mode); + flags[PARENT] = AuHinJob_ISDIR; + flags[CHILD] = 0; + if (isdir) + flags[CHILD] = AuHinJob_ISDIR; + switch (mask & IN_ALL_EVENTS) { + case IN_MOVED_FROM: + case IN_MOVED_TO: + AuDebugOn(!h_child_name || !h_child_inode); + au_fset_hinjob(flags[CHILD], GEN); + au_fset_hinjob(flags[CHILD], XINO0); + au_fset_hinjob(flags[CHILD], MNTPNT); + au_fset_hinjob(flags[PARENT], DIRENT); + break; + + case IN_CREATE: + AuDebugOn(!h_child_name || !h_child_inode); + au_fset_hinjob(flags[PARENT], DIRENT); + au_fset_hinjob(flags[CHILD], GEN); + break; + + case IN_DELETE: + /* + * aufs never be able to get this child inode. + * revalidation should be in d_revalidate() + * by checking i_nlink, i_generation or d_unhashed(). + */ + AuDebugOn(!h_child_name); + au_fset_hinjob(flags[PARENT], DIRENT); + au_fset_hinjob(flags[CHILD], GEN); + au_fset_hinjob(flags[CHILD], TRYXINO0); + au_fset_hinjob(flags[CHILD], MNTPNT); + break; + + default: + AuDebugOn(1); + } + + if (wh) + h_child_inode = NULL; + + /* iput() and kfree() will be called in postproc() */ + /* + * inotify_mutex is already acquired and kmalloc/prune_icache may lock + * iprune_mutex. strange. + */ + lockdep_off(); + args = kmalloc(sizeof(*args) + len + 1, GFP_NOFS); + lockdep_on(); + if (unlikely(!args)) { + AuErr1("no memory\n"); + iput(dir); + return; + } + args->flags[PARENT] = flags[PARENT]; + args->flags[CHILD] = flags[CHILD]; + args->mask = mask; + args->dir = dir; + args->h_dir = igrab(watch->inode); + if (h_child_inode) + h_child_inode = igrab(h_child_inode); /* can be NULL */ + args->h_child_inode = h_child_inode; + args->h_child_nlen = len; + if (len) { + p = (void *)args; + p += sizeof(*args); + memcpy(p, h_child_name, len + 1); + } + + lockdep_off(); + wkq_err = au_wkq_nowait(postproc, args, dir->i_sb); + lockdep_on(); + if (unlikely(wkq_err)) + AuErr("wkq %d\n", wkq_err); +} + +static void aufs_inotify_destroy(struct inotify_watch *watch __maybe_unused) +{ + return; +} + +static struct inotify_operations aufs_inotify_ops = { + .handle_event = aufs_inotify, + .destroy_watch = aufs_inotify_destroy +}; + +/* ---------------------------------------------------------------------- */ + +static void au_hin_destroy_cache(void) +{ + kmem_cache_destroy(au_cachep[AuCache_HINOTIFY]); + au_cachep[AuCache_HINOTIFY] = NULL; +} + +int __init au_hinotify_init(void) +{ + int err; + + err = -ENOMEM; + au_cachep[AuCache_HINOTIFY] = AuCache(au_hinotify); + if (au_cachep[AuCache_HINOTIFY]) { + err = 0; + au_hin_handle = inotify_init(&aufs_inotify_ops); + if (IS_ERR(au_hin_handle)) { + err = PTR_ERR(au_hin_handle); + au_hin_destroy_cache(); + } + } + AuTraceErr(err); + return err; +} + +void au_hinotify_fin(void) +{ + inotify_destroy(au_hin_handle); + if (au_cachep[AuCache_HINOTIFY]) + au_hin_destroy_cache(); +} -- 1.6.1.284.g5dc13