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-rw-r--r--fs/aufs/hnotify.c715
1 files changed, 715 insertions, 0 deletions
diff --git a/fs/aufs/hnotify.c b/fs/aufs/hnotify.c
new file mode 100644
index 000000000000..231edd1b4753
--- /dev/null
+++ b/fs/aufs/hnotify.c
@@ -0,0 +1,715 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005-2020 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * abstraction to notify the direct changes on lower directories
+ */
+
+/* #include <linux/iversion.h> */
+#include "aufs.h"
+
+int au_hn_alloc(struct au_hinode *hinode, struct inode *inode)
+{
+ int err;
+ struct au_hnotify *hn;
+
+ err = -ENOMEM;
+ hn = au_cache_alloc_hnotify();
+ if (hn) {
+ hn->hn_aufs_inode = inode;
+ hinode->hi_notify = hn;
+ err = au_hnotify_op.alloc(hinode);
+ AuTraceErr(err);
+ if (unlikely(err)) {
+ hinode->hi_notify = NULL;
+ au_cache_free_hnotify(hn);
+ /*
+ * The upper dir was removed by udba, but the same named
+ * dir left. In this case, aufs assigns a new inode
+ * number and set the monitor again.
+ * For the lower dir, the old monitor is still left.
+ */
+ if (err == -EEXIST)
+ err = 0;
+ }
+ }
+
+ AuTraceErr(err);
+ return err;
+}
+
+void au_hn_free(struct au_hinode *hinode)
+{
+ struct au_hnotify *hn;
+
+ hn = hinode->hi_notify;
+ if (hn) {
+ hinode->hi_notify = NULL;
+ if (au_hnotify_op.free(hinode, hn))
+ au_cache_free_hnotify(hn);
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void au_hn_ctl(struct au_hinode *hinode, int do_set)
+{
+ if (hinode->hi_notify)
+ au_hnotify_op.ctl(hinode, do_set);
+}
+
+void au_hn_reset(struct inode *inode, unsigned int flags)
+{
+ aufs_bindex_t bindex, bbot;
+ struct inode *hi;
+ struct dentry *iwhdentry;
+
+ bbot = au_ibbot(inode);
+ for (bindex = au_ibtop(inode); bindex <= bbot; bindex++) {
+ hi = au_h_iptr(inode, bindex);
+ if (!hi)
+ continue;
+
+ /* inode_lock_nested(hi, 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);
+ /* inode_unlock(hi); */
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int hn_xino(struct inode *inode, struct inode *h_inode)
+{
+ int err;
+ aufs_bindex_t bindex, bbot, bfound, btop;
+ struct inode *h_i;
+
+ err = 0;
+ if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
+ pr_warn("branch root dir was changed\n");
+ goto out;
+ }
+
+ bfound = -1;
+ bbot = au_ibbot(inode);
+ btop = au_ibtop(inode);
+#if 0 /* reserved for future use */
+ if (bindex == bbot) {
+ /* keep this ino in rename case */
+ goto out;
+ }
+#endif
+ for (bindex = btop; bindex <= bbot; bindex++)
+ if (au_h_iptr(inode, bindex) == h_inode) {
+ bfound = bindex;
+ break;
+ }
+ if (bfound < 0)
+ goto out;
+
+ for (bindex = btop; bindex <= bbot; bindex++) {
+ h_i = au_h_iptr(inode, bindex);
+ if (!h_i)
+ continue;
+
+ err = au_xino_write(inode->i_sb, bindex, h_i->i_ino, /*ino*/0);
+ /* ignore this error */
+ /* bad action? */
+ }
+
+ /* children inode number will be broken */
+
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+static int hn_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;
+
+ au_digen_dec(d);
+ if (d_really_is_positive(d))
+ /* todo: reset children xino?
+ cached children only? */
+ au_iigen_dec(d_inode(d));
+ }
+ }
+
+out_dpages:
+ au_dpages_free(&dpages);
+out:
+ return err;
+}
+
+/*
+ * return 0 if processed.
+ */
+static int hn_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)) {
+ pr_warn("branch root dir was changed\n");
+ err = 0;
+ goto out;
+ }
+
+ if (!isdir) {
+ AuDebugOn(!name);
+ au_iigen_dec(inode);
+ spin_lock(&inode->i_lock);
+ hlist_for_each_entry(d, &inode->i_dentry, d_u.d_alias) {
+ spin_lock(&d->d_lock);
+ dname = &d->d_name;
+ if (dname->len != nlen
+ && memcmp(dname->name, name, nlen)) {
+ spin_unlock(&d->d_lock);
+ continue;
+ }
+ err = 0;
+ au_digen_dec(d);
+ spin_unlock(&d->d_lock);
+ break;
+ }
+ spin_unlock(&inode->i_lock);
+ } else {
+ au_fset_si(au_sbi(inode->i_sb), FAILED_REFRESH_DIR);
+ d = d_find_any_alias(inode);
+ if (!d) {
+ au_iigen_dec(inode);
+ goto out;
+ }
+
+ spin_lock(&d->d_lock);
+ dname = &d->d_name;
+ if (dname->len == nlen && !memcmp(dname->name, name, nlen)) {
+ spin_unlock(&d->d_lock);
+ err = hn_gen_tree(d);
+ spin_lock(&d->d_lock);
+ }
+ spin_unlock(&d->d_lock);
+ dput(d);
+ }
+
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+static int hn_gen_by_name(struct dentry *dentry, const unsigned int isdir)
+{
+ int err;
+
+ if (IS_ROOT(dentry)) {
+ pr_warn("branch root dir was changed\n");
+ return 0;
+ }
+
+ err = 0;
+ if (!isdir) {
+ au_digen_dec(dentry);
+ if (d_really_is_positive(dentry))
+ au_iigen_dec(d_inode(dentry));
+ } else {
+ au_fset_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIR);
+ if (d_really_is_positive(dentry))
+ err = hn_gen_tree(dentry);
+ }
+
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* hnotify job flags */
+#define AuHnJob_XINO0 1
+#define AuHnJob_GEN (1 << 1)
+#define AuHnJob_DIRENT (1 << 2)
+#define AuHnJob_ISDIR (1 << 3)
+#define AuHnJob_TRYXINO0 (1 << 4)
+#define AuHnJob_MNTPNT (1 << 5)
+#define au_ftest_hnjob(flags, name) ((flags) & AuHnJob_##name)
+#define au_fset_hnjob(flags, name) \
+ do { (flags) |= AuHnJob_##name; } while (0)
+#define au_fclr_hnjob(flags, name) \
+ do { (flags) &= ~AuHnJob_##name; } while (0)
+
+enum {
+ AuHn_CHILD,
+ AuHn_PARENT,
+ AuHnLast
+};
+
+struct au_hnotify_args {
+ struct inode *h_dir, *dir, *h_child_inode;
+ u32 mask;
+ unsigned int flags[AuHnLast];
+ unsigned int h_child_nlen;
+ char h_child_name[];
+};
+
+struct hn_job_args {
+ unsigned int flags;
+ struct inode *inode, *h_inode, *dir, *h_dir;
+ struct dentry *dentry;
+ char *h_name;
+ int h_nlen;
+};
+
+static int hn_job(struct hn_job_args *a)
+{
+ const unsigned int isdir = au_ftest_hnjob(a->flags, ISDIR);
+ int e;
+
+ /* reset xino */
+ if (au_ftest_hnjob(a->flags, XINO0) && a->inode)
+ hn_xino(a->inode, a->h_inode); /* ignore this error */
+
+ if (au_ftest_hnjob(a->flags, TRYXINO0)
+ && a->inode
+ && a->h_inode) {
+ inode_lock_shared_nested(a->h_inode, AuLsc_I_CHILD);
+ if (!a->h_inode->i_nlink
+ && !(a->h_inode->i_state & I_LINKABLE))
+ hn_xino(a->inode, a->h_inode); /* ignore this error */
+ inode_unlock_shared(a->h_inode);
+ }
+
+ /* make the generation obsolete */
+ if (au_ftest_hnjob(a->flags, GEN)) {
+ e = -1;
+ if (a->inode)
+ e = hn_gen_by_inode(a->h_name, a->h_nlen, a->inode,
+ isdir);
+ if (e && a->dentry)
+ hn_gen_by_name(a->dentry, isdir);
+ /* ignore this error */
+ }
+
+ /* make dir entries obsolete */
+ if (au_ftest_hnjob(a->flags, DIRENT) && a->inode) {
+ struct au_vdir *vdir;
+
+ vdir = au_ivdir(a->inode);
+ if (vdir)
+ vdir->vd_jiffy = 0;
+ /* IMustLock(a->inode); */
+ /* inode_inc_iversion(a->inode); */
+ }
+
+ /* can do nothing but warn */
+ if (au_ftest_hnjob(a->flags, MNTPNT)
+ && a->dentry
+ && d_mountpoint(a->dentry))
+ pr_warn("mount-point %pd is removed or renamed\n", a->dentry);
+
+ return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+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_any_alias(dir);
+ if (!parent)
+ return NULL;
+
+ dentry = NULL;
+ spin_lock(&parent->d_lock);
+ list_for_each_entry(d, &parent->d_subdirs, d_child) {
+ /* AuDbg("%pd\n", d); */
+ spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
+ dname = &d->d_name;
+ if (dname->len != nlen || memcmp(dname->name, name, nlen))
+ goto cont_unlock;
+ if (au_di(d))
+ au_digen_dec(d);
+ else
+ goto cont_unlock;
+ if (au_dcount(d) > 0) {
+ dentry = dget_dlock(d);
+ spin_unlock(&d->d_lock);
+ break;
+ }
+
+cont_unlock:
+ spin_unlock(&d->d_lock);
+ }
+ spin_unlock(&parent->d_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)) {
+ pr_warn("wrong root branch\n");
+ iput(inode);
+ inode = NULL;
+ goto out;
+ }
+
+ ii_write_lock_child(inode);
+
+out:
+ return inode;
+}
+
+static void au_hn_bh(void *_args)
+{
+ struct au_hnotify_args *a = _args;
+ struct super_block *sb;
+ aufs_bindex_t bindex, bbot, bfound;
+ unsigned char xino, try_iput;
+ int err;
+ struct inode *inode;
+ ino_t h_ino;
+ struct hn_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, i%lu, hi%lu, hci%lu\n",
+ 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);
+ si_write_lock(sb, AuLock_NOPLMW);
+
+ if (au_opt_test(sbinfo->si_mntflags, DIRREN))
+ switch (a->mask & FS_EVENTS_POSS_ON_CHILD) {
+ case FS_MOVED_FROM:
+ case FS_MOVED_TO:
+ AuWarn1("DIRREN with UDBA may not work correctly "
+ "for the direct rename(2)\n");
+ }
+
+ ii_read_lock_parent(a->dir);
+ bfound = -1;
+ bbot = au_ibbot(a->dir);
+ for (bindex = au_ibtop(a->dir); bindex <= bbot; 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_hnjob(a->flags[AuHn_CHILD], GEN)
+ || au_ftest_hnjob(a->flags[AuHn_CHILD], MNTPNT)))
+ dentry = lookup_wlock_by_name(a->h_child_name, a->h_child_nlen,
+ a->dir);
+ try_iput = 0;
+ if (dentry && d_really_is_positive(dentry))
+ inode = d_inode(dentry);
+ if (xino && !inode && h_ino
+ && (au_ftest_hnjob(a->flags[AuHn_CHILD], XINO0)
+ || au_ftest_hnjob(a->flags[AuHn_CHILD], TRYXINO0)
+ || au_ftest_hnjob(a->flags[AuHn_CHILD], GEN))) {
+ inode = lookup_wlock_by_ino(sb, bfound, h_ino);
+ try_iput = 1;
+ }
+
+ args.flags = a->flags[AuHn_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 = hn_job(&args);
+ if (dentry) {
+ if (au_di(dentry))
+ 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[AuHn_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 = hn_job(&args);
+ ii_write_unlock(a->dir);
+
+out:
+ iput(a->h_child_inode);
+ iput(a->h_dir);
+ iput(a->dir);
+ si_write_unlock(sb);
+ au_nwt_done(&sbinfo->si_nowait);
+ au_kfree_rcu(a);
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_hnotify(struct inode *h_dir, struct au_hnotify *hnotify, u32 mask,
+ const struct qstr *h_child_qstr, struct inode *h_child_inode)
+{
+ int err, len;
+ unsigned int flags[AuHnLast], f;
+ unsigned char isdir, isroot, wh;
+ struct inode *dir;
+ struct au_hnotify_args *args;
+ char *p, *h_child_name;
+
+ err = 0;
+ AuDebugOn(!hnotify || !hnotify->hn_aufs_inode);
+ dir = igrab(hnotify->hn_aufs_inode);
+ if (!dir)
+ goto out;
+
+ isroot = (dir->i_ino == AUFS_ROOT_INO);
+ wh = 0;
+ h_child_name = (void *)h_child_qstr->name;
+ len = h_child_qstr->len;
+ if (h_child_name) {
+ if (len > AUFS_WH_PFX_LEN
+ && !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[AuHn_PARENT] = AuHnJob_ISDIR;
+ flags[AuHn_CHILD] = 0;
+ if (isdir)
+ flags[AuHn_CHILD] = AuHnJob_ISDIR;
+ au_fset_hnjob(flags[AuHn_PARENT], DIRENT);
+ au_fset_hnjob(flags[AuHn_CHILD], GEN);
+ switch (mask & ALL_FSNOTIFY_DIRENT_EVENTS) {
+ case FS_MOVED_FROM:
+ case FS_MOVED_TO:
+ au_fset_hnjob(flags[AuHn_CHILD], XINO0);
+ au_fset_hnjob(flags[AuHn_CHILD], MNTPNT);
+ /*FALLTHROUGH*/
+ case FS_CREATE:
+ AuDebugOn(!h_child_name);
+ break;
+
+ case FS_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_hnjob(flags[AuHn_CHILD], TRYXINO0);
+ au_fset_hnjob(flags[AuHn_CHILD], MNTPNT);
+ break;
+
+ default:
+ AuDebugOn(1);
+ }
+
+ if (wh)
+ h_child_inode = NULL;
+
+ err = -ENOMEM;
+ /* iput() and kfree() will be called in au_hnotify() */
+ args = kmalloc(sizeof(*args) + len + 1, GFP_NOFS);
+ if (unlikely(!args)) {
+ AuErr1("no memory\n");
+ iput(dir);
+ goto out;
+ }
+ args->flags[AuHn_PARENT] = flags[AuHn_PARENT];
+ args->flags[AuHn_CHILD] = flags[AuHn_CHILD];
+ args->mask = mask;
+ args->dir = dir;
+ args->h_dir = igrab(h_dir);
+ 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);
+ p[len] = 0;
+ }
+
+ /* NFS fires the event for silly-renamed one from kworker */
+ f = 0;
+ if (!dir->i_nlink
+ || (au_test_nfs(h_dir->i_sb) && (mask & FS_DELETE)))
+ f = AuWkq_NEST;
+ err = au_wkq_nowait(au_hn_bh, args, dir->i_sb, f);
+ if (unlikely(err)) {
+ pr_err("wkq %d\n", err);
+ iput(args->h_child_inode);
+ iput(args->h_dir);
+ iput(args->dir);
+ au_kfree_rcu(args);
+ }
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_hnotify_reset_br(unsigned int udba, struct au_branch *br, int perm)
+{
+ int err;
+
+ AuDebugOn(!(udba & AuOptMask_UDBA));
+
+ err = 0;
+ if (au_hnotify_op.reset_br)
+ err = au_hnotify_op.reset_br(udba, br, perm);
+
+ return err;
+}
+
+int au_hnotify_init_br(struct au_branch *br, int perm)
+{
+ int err;
+
+ err = 0;
+ if (au_hnotify_op.init_br)
+ err = au_hnotify_op.init_br(br, perm);
+
+ return err;
+}
+
+void au_hnotify_fin_br(struct au_branch *br)
+{
+ if (au_hnotify_op.fin_br)
+ au_hnotify_op.fin_br(br);
+}
+
+static void au_hn_destroy_cache(void)
+{
+ kmem_cache_destroy(au_cache[AuCache_HNOTIFY]);
+ au_cache[AuCache_HNOTIFY] = NULL;
+}
+
+int __init au_hnotify_init(void)
+{
+ int err;
+
+ err = -ENOMEM;
+ au_cache[AuCache_HNOTIFY] = AuCache(au_hnotify);
+ if (au_cache[AuCache_HNOTIFY]) {
+ err = 0;
+ if (au_hnotify_op.init)
+ err = au_hnotify_op.init();
+ if (unlikely(err))
+ au_hn_destroy_cache();
+ }
+ AuTraceErr(err);
+ return err;
+}
+
+void au_hnotify_fin(void)
+{
+ if (au_hnotify_op.fin)
+ au_hnotify_op.fin();
+
+ /* cf. au_cache_fin() */
+ if (au_cache[AuCache_HNOTIFY])
+ au_hn_destroy_cache();
+}
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-28 17:58:00 +0000