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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-23 12:33:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-23 12:33:14 -0300
commita700f2d8e79ff80041078f160fe1edccf89b0c66 (patch)
tree070bc692c19c5980c081222a6f7223869b1560f3 /fs/aufs/i_op_ren.c
parentd5ad8b932c22e2790c2b27351116de96603df63a (diff)
Linux-libre 4.2.1-gnupck-4.2.1-gnu
Diffstat (limited to 'fs/aufs/i_op_ren.c')
-rw-r--r--fs/aufs/i_op_ren.c1017
1 files changed, 1017 insertions, 0 deletions
diff --git a/fs/aufs/i_op_ren.c b/fs/aufs/i_op_ren.c
new file mode 100644
index 000000000..4db778057
--- /dev/null
+++ b/fs/aufs/i_op_ren.c
@@ -0,0 +1,1017 @@
+/*
+ * Copyright (C) 2005-2015 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/>.
+ */
+
+/*
+ * inode operation (rename entry)
+ * todo: this is crazy monster
+ */
+
+#include "aufs.h"
+
+enum { AuSRC, AuDST, AuSrcDst };
+enum { AuPARENT, AuCHILD, AuParentChild };
+
+#define AuRen_ISDIR 1
+#define AuRen_ISSAMEDIR (1 << 1)
+#define AuRen_WHSRC (1 << 2)
+#define AuRen_WHDST (1 << 3)
+#define AuRen_MNT_WRITE (1 << 4)
+#define AuRen_DT_DSTDIR (1 << 5)
+#define AuRen_DIROPQ (1 << 6)
+#define au_ftest_ren(flags, name) ((flags) & AuRen_##name)
+#define au_fset_ren(flags, name) \
+ do { (flags) |= AuRen_##name; } while (0)
+#define au_fclr_ren(flags, name) \
+ do { (flags) &= ~AuRen_##name; } while (0)
+
+struct au_ren_args {
+ struct {
+ struct dentry *dentry, *h_dentry, *parent, *h_parent,
+ *wh_dentry;
+ struct inode *dir, *inode;
+ struct au_hinode *hdir;
+ struct au_dtime dt[AuParentChild];
+ aufs_bindex_t bstart;
+ } sd[AuSrcDst];
+
+#define src_dentry sd[AuSRC].dentry
+#define src_dir sd[AuSRC].dir
+#define src_inode sd[AuSRC].inode
+#define src_h_dentry sd[AuSRC].h_dentry
+#define src_parent sd[AuSRC].parent
+#define src_h_parent sd[AuSRC].h_parent
+#define src_wh_dentry sd[AuSRC].wh_dentry
+#define src_hdir sd[AuSRC].hdir
+#define src_h_dir sd[AuSRC].hdir->hi_inode
+#define src_dt sd[AuSRC].dt
+#define src_bstart sd[AuSRC].bstart
+
+#define dst_dentry sd[AuDST].dentry
+#define dst_dir sd[AuDST].dir
+#define dst_inode sd[AuDST].inode
+#define dst_h_dentry sd[AuDST].h_dentry
+#define dst_parent sd[AuDST].parent
+#define dst_h_parent sd[AuDST].h_parent
+#define dst_wh_dentry sd[AuDST].wh_dentry
+#define dst_hdir sd[AuDST].hdir
+#define dst_h_dir sd[AuDST].hdir->hi_inode
+#define dst_dt sd[AuDST].dt
+#define dst_bstart sd[AuDST].bstart
+
+ struct dentry *h_trap;
+ struct au_branch *br;
+ struct au_hinode *src_hinode;
+ struct path h_path;
+ struct au_nhash whlist;
+ aufs_bindex_t btgt, src_bwh, src_bdiropq;
+
+ unsigned int flags;
+
+ struct au_whtmp_rmdir *thargs;
+ struct dentry *h_dst;
+};
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * functions for reverting.
+ * when an error happened in a single rename systemcall, we should revert
+ * everything as if nothing happend.
+ * we don't need to revert the copied-up/down the parent dir since they are
+ * harmless.
+ */
+
+#define RevertFailure(fmt, ...) do { \
+ AuIOErr("revert failure: " fmt " (%d, %d)\n", \
+ ##__VA_ARGS__, err, rerr); \
+ err = -EIO; \
+} while (0)
+
+static void au_ren_rev_diropq(int err, struct au_ren_args *a)
+{
+ int rerr;
+
+ au_hn_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
+ rerr = au_diropq_remove(a->src_dentry, a->btgt);
+ au_hn_imtx_unlock(a->src_hinode);
+ au_set_dbdiropq(a->src_dentry, a->src_bdiropq);
+ if (rerr)
+ RevertFailure("remove diropq %pd", a->src_dentry);
+}
+
+static void au_ren_rev_rename(int err, struct au_ren_args *a)
+{
+ int rerr;
+ struct inode *delegated;
+
+ a->h_path.dentry = vfsub_lkup_one(&a->src_dentry->d_name,
+ a->src_h_parent);
+ rerr = PTR_ERR(a->h_path.dentry);
+ if (IS_ERR(a->h_path.dentry)) {
+ RevertFailure("lkup one %pd", a->src_dentry);
+ return;
+ }
+
+ delegated = NULL;
+ rerr = vfsub_rename(a->dst_h_dir,
+ au_h_dptr(a->src_dentry, a->btgt),
+ a->src_h_dir, &a->h_path, &delegated);
+ if (unlikely(rerr == -EWOULDBLOCK)) {
+ pr_warn("cannot retry for NFSv4 delegation"
+ " for an internal rename\n");
+ iput(delegated);
+ }
+ d_drop(a->h_path.dentry);
+ dput(a->h_path.dentry);
+ /* au_set_h_dptr(a->src_dentry, a->btgt, NULL); */
+ if (rerr)
+ RevertFailure("rename %pd", a->src_dentry);
+}
+
+static void au_ren_rev_whtmp(int err, struct au_ren_args *a)
+{
+ int rerr;
+ struct inode *delegated;
+
+ a->h_path.dentry = vfsub_lkup_one(&a->dst_dentry->d_name,
+ a->dst_h_parent);
+ rerr = PTR_ERR(a->h_path.dentry);
+ if (IS_ERR(a->h_path.dentry)) {
+ RevertFailure("lkup one %pd", a->dst_dentry);
+ return;
+ }
+ if (d_is_positive(a->h_path.dentry)) {
+ d_drop(a->h_path.dentry);
+ dput(a->h_path.dentry);
+ return;
+ }
+
+ delegated = NULL;
+ rerr = vfsub_rename(a->dst_h_dir, a->h_dst, a->dst_h_dir, &a->h_path,
+ &delegated);
+ if (unlikely(rerr == -EWOULDBLOCK)) {
+ pr_warn("cannot retry for NFSv4 delegation"
+ " for an internal rename\n");
+ iput(delegated);
+ }
+ d_drop(a->h_path.dentry);
+ dput(a->h_path.dentry);
+ if (!rerr)
+ au_set_h_dptr(a->dst_dentry, a->btgt, dget(a->h_dst));
+ else
+ RevertFailure("rename %pd", a->h_dst);
+}
+
+static void au_ren_rev_whsrc(int err, struct au_ren_args *a)
+{
+ int rerr;
+
+ a->h_path.dentry = a->src_wh_dentry;
+ rerr = au_wh_unlink_dentry(a->src_h_dir, &a->h_path, a->src_dentry);
+ au_set_dbwh(a->src_dentry, a->src_bwh);
+ if (rerr)
+ RevertFailure("unlink %pd", a->src_wh_dentry);
+}
+#undef RevertFailure
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * when we have to copyup the renaming entry, do it with the rename-target name
+ * in order to minimize the cost (the later actual rename is unnecessary).
+ * otherwise rename it on the target branch.
+ */
+static int au_ren_or_cpup(struct au_ren_args *a)
+{
+ int err;
+ struct dentry *d;
+ struct inode *delegated;
+
+ d = a->src_dentry;
+ if (au_dbstart(d) == a->btgt) {
+ a->h_path.dentry = a->dst_h_dentry;
+ if (au_ftest_ren(a->flags, DIROPQ)
+ && au_dbdiropq(d) == a->btgt)
+ au_fclr_ren(a->flags, DIROPQ);
+ AuDebugOn(au_dbstart(d) != a->btgt);
+ delegated = NULL;
+ err = vfsub_rename(a->src_h_dir, au_h_dptr(d, a->btgt),
+ a->dst_h_dir, &a->h_path, &delegated);
+ if (unlikely(err == -EWOULDBLOCK)) {
+ pr_warn("cannot retry for NFSv4 delegation"
+ " for an internal rename\n");
+ iput(delegated);
+ }
+ } else
+ BUG();
+
+ if (!err && a->h_dst)
+ /* it will be set to dinfo later */
+ dget(a->h_dst);
+
+ return err;
+}
+
+/* cf. aufs_rmdir() */
+static int au_ren_del_whtmp(struct au_ren_args *a)
+{
+ int err;
+ struct inode *dir;
+
+ dir = a->dst_dir;
+ SiMustAnyLock(dir->i_sb);
+ if (!au_nhash_test_longer_wh(&a->whlist, a->btgt,
+ au_sbi(dir->i_sb)->si_dirwh)
+ || au_test_fs_remote(a->h_dst->d_sb)) {
+ err = au_whtmp_rmdir(dir, a->btgt, a->h_dst, &a->whlist);
+ if (unlikely(err))
+ pr_warn("failed removing whtmp dir %pd (%d), "
+ "ignored.\n", a->h_dst, err);
+ } else {
+ au_nhash_wh_free(&a->thargs->whlist);
+ a->thargs->whlist = a->whlist;
+ a->whlist.nh_num = 0;
+ au_whtmp_kick_rmdir(dir, a->btgt, a->h_dst, a->thargs);
+ dput(a->h_dst);
+ a->thargs = NULL;
+ }
+
+ return 0;
+}
+
+/* make it 'opaque' dir. */
+static int au_ren_diropq(struct au_ren_args *a)
+{
+ int err;
+ struct dentry *diropq;
+
+ err = 0;
+ a->src_bdiropq = au_dbdiropq(a->src_dentry);
+ a->src_hinode = au_hi(a->src_inode, a->btgt);
+ au_hn_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
+ diropq = au_diropq_create(a->src_dentry, a->btgt);
+ au_hn_imtx_unlock(a->src_hinode);
+ if (IS_ERR(diropq))
+ err = PTR_ERR(diropq);
+ else
+ dput(diropq);
+
+ return err;
+}
+
+static int do_rename(struct au_ren_args *a)
+{
+ int err;
+ struct dentry *d, *h_d;
+
+ /* prepare workqueue args for asynchronous rmdir */
+ h_d = a->dst_h_dentry;
+ if (au_ftest_ren(a->flags, ISDIR) && d_is_positive(h_d)) {
+ err = -ENOMEM;
+ a->thargs = au_whtmp_rmdir_alloc(a->src_dentry->d_sb, GFP_NOFS);
+ if (unlikely(!a->thargs))
+ goto out;
+ a->h_dst = dget(h_d);
+ }
+
+ /* create whiteout for src_dentry */
+ if (au_ftest_ren(a->flags, WHSRC)) {
+ a->src_bwh = au_dbwh(a->src_dentry);
+ AuDebugOn(a->src_bwh >= 0);
+ a->src_wh_dentry
+ = au_wh_create(a->src_dentry, a->btgt, a->src_h_parent);
+ err = PTR_ERR(a->src_wh_dentry);
+ if (IS_ERR(a->src_wh_dentry))
+ goto out_thargs;
+ }
+
+ /* lookup whiteout for dentry */
+ if (au_ftest_ren(a->flags, WHDST)) {
+ h_d = au_wh_lkup(a->dst_h_parent, &a->dst_dentry->d_name,
+ a->br);
+ err = PTR_ERR(h_d);
+ if (IS_ERR(h_d))
+ goto out_whsrc;
+ if (d_is_negative(h_d))
+ dput(h_d);
+ else
+ a->dst_wh_dentry = h_d;
+ }
+
+ /* rename dentry to tmpwh */
+ if (a->thargs) {
+ err = au_whtmp_ren(a->dst_h_dentry, a->br);
+ if (unlikely(err))
+ goto out_whdst;
+
+ d = a->dst_dentry;
+ au_set_h_dptr(d, a->btgt, NULL);
+ err = au_lkup_neg(d, a->btgt, /*wh*/0);
+ if (unlikely(err))
+ goto out_whtmp;
+ a->dst_h_dentry = au_h_dptr(d, a->btgt);
+ }
+
+ BUG_ON(d_is_positive(a->dst_h_dentry) && a->src_bstart != a->btgt);
+
+ /* rename by vfs_rename or cpup */
+ d = a->dst_dentry;
+ if (au_ftest_ren(a->flags, ISDIR)
+ && (a->dst_wh_dentry
+ || au_dbdiropq(d) == a->btgt
+ /* hide the lower to keep xino */
+ || a->btgt < au_dbend(d)
+ || au_opt_test(au_mntflags(d->d_sb), ALWAYS_DIROPQ)))
+ au_fset_ren(a->flags, DIROPQ);
+ err = au_ren_or_cpup(a);
+ if (unlikely(err))
+ /* leave the copied-up one */
+ goto out_whtmp;
+
+ /* make dir opaque */
+ if (au_ftest_ren(a->flags, DIROPQ)) {
+ err = au_ren_diropq(a);
+ if (unlikely(err))
+ goto out_rename;
+ }
+
+ /* update target timestamps */
+ AuDebugOn(au_dbstart(a->src_dentry) != a->btgt);
+ a->h_path.dentry = au_h_dptr(a->src_dentry, a->btgt);
+ vfsub_update_h_iattr(&a->h_path, /*did*/NULL); /*ignore*/
+ a->src_inode->i_ctime = d_inode(a->h_path.dentry)->i_ctime;
+
+ /* remove whiteout for dentry */
+ if (a->dst_wh_dentry) {
+ a->h_path.dentry = a->dst_wh_dentry;
+ err = au_wh_unlink_dentry(a->dst_h_dir, &a->h_path,
+ a->dst_dentry);
+ if (unlikely(err))
+ goto out_diropq;
+ }
+
+ /* remove whtmp */
+ if (a->thargs)
+ au_ren_del_whtmp(a); /* ignore this error */
+
+ au_fhsm_wrote(a->src_dentry->d_sb, a->btgt, /*force*/0);
+ err = 0;
+ goto out_success;
+
+out_diropq:
+ if (au_ftest_ren(a->flags, DIROPQ))
+ au_ren_rev_diropq(err, a);
+out_rename:
+ au_ren_rev_rename(err, a);
+ dput(a->h_dst);
+out_whtmp:
+ if (a->thargs)
+ au_ren_rev_whtmp(err, a);
+out_whdst:
+ dput(a->dst_wh_dentry);
+ a->dst_wh_dentry = NULL;
+out_whsrc:
+ if (a->src_wh_dentry)
+ au_ren_rev_whsrc(err, a);
+out_success:
+ dput(a->src_wh_dentry);
+ dput(a->dst_wh_dentry);
+out_thargs:
+ if (a->thargs) {
+ dput(a->h_dst);
+ au_whtmp_rmdir_free(a->thargs);
+ a->thargs = NULL;
+ }
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * test if @dentry dir can be rename destination or not.
+ * success means, it is a logically empty dir.
+ */
+static int may_rename_dstdir(struct dentry *dentry, struct au_nhash *whlist)
+{
+ return au_test_empty(dentry, whlist);
+}
+
+/*
+ * test if @dentry dir can be rename source or not.
+ * if it can, return 0 and @children is filled.
+ * success means,
+ * - it is a logically empty dir.
+ * - or, it exists on writable branch and has no children including whiteouts
+ * on the lower branch.
+ */
+static int may_rename_srcdir(struct dentry *dentry, aufs_bindex_t btgt)
+{
+ int err;
+ unsigned int rdhash;
+ aufs_bindex_t bstart;
+
+ bstart = au_dbstart(dentry);
+ if (bstart != btgt) {
+ struct au_nhash whlist;
+
+ SiMustAnyLock(dentry->d_sb);
+ rdhash = au_sbi(dentry->d_sb)->si_rdhash;
+ if (!rdhash)
+ rdhash = au_rdhash_est(au_dir_size(/*file*/NULL,
+ dentry));
+ err = au_nhash_alloc(&whlist, rdhash, GFP_NOFS);
+ if (unlikely(err))
+ goto out;
+ err = au_test_empty(dentry, &whlist);
+ au_nhash_wh_free(&whlist);
+ goto out;
+ }
+
+ if (bstart == au_dbtaildir(dentry))
+ return 0; /* success */
+
+ err = au_test_empty_lower(dentry);
+
+out:
+ if (err == -ENOTEMPTY) {
+ AuWarn1("renaming dir who has child(ren) on multiple branches,"
+ " is not supported\n");
+ err = -EXDEV;
+ }
+ return err;
+}
+
+/* side effect: sets whlist and h_dentry */
+static int au_ren_may_dir(struct au_ren_args *a)
+{
+ int err;
+ unsigned int rdhash;
+ struct dentry *d;
+
+ d = a->dst_dentry;
+ SiMustAnyLock(d->d_sb);
+
+ err = 0;
+ if (au_ftest_ren(a->flags, ISDIR) && a->dst_inode) {
+ rdhash = au_sbi(d->d_sb)->si_rdhash;
+ if (!rdhash)
+ rdhash = au_rdhash_est(au_dir_size(/*file*/NULL, d));
+ err = au_nhash_alloc(&a->whlist, rdhash, GFP_NOFS);
+ if (unlikely(err))
+ goto out;
+
+ au_set_dbstart(d, a->dst_bstart);
+ err = may_rename_dstdir(d, &a->whlist);
+ au_set_dbstart(d, a->btgt);
+ }
+ a->dst_h_dentry = au_h_dptr(d, au_dbstart(d));
+ if (unlikely(err))
+ goto out;
+
+ d = a->src_dentry;
+ a->src_h_dentry = au_h_dptr(d, au_dbstart(d));
+ if (au_ftest_ren(a->flags, ISDIR)) {
+ err = may_rename_srcdir(d, a->btgt);
+ if (unlikely(err)) {
+ au_nhash_wh_free(&a->whlist);
+ a->whlist.nh_num = 0;
+ }
+ }
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * simple tests for rename.
+ * following the checks in vfs, plus the parent-child relationship.
+ */
+static int au_may_ren(struct au_ren_args *a)
+{
+ int err, isdir;
+ struct inode *h_inode;
+
+ if (a->src_bstart == a->btgt) {
+ err = au_may_del(a->src_dentry, a->btgt, a->src_h_parent,
+ au_ftest_ren(a->flags, ISDIR));
+ if (unlikely(err))
+ goto out;
+ err = -EINVAL;
+ if (unlikely(a->src_h_dentry == a->h_trap))
+ goto out;
+ }
+
+ err = 0;
+ if (a->dst_bstart != a->btgt)
+ goto out;
+
+ err = -ENOTEMPTY;
+ if (unlikely(a->dst_h_dentry == a->h_trap))
+ goto out;
+
+ err = -EIO;
+ isdir = !!au_ftest_ren(a->flags, ISDIR);
+ if (d_really_is_negative(a->dst_dentry)) {
+ if (d_is_negative(a->dst_h_dentry))
+ err = au_may_add(a->dst_dentry, a->btgt,
+ a->dst_h_parent, isdir);
+ } else {
+ if (unlikely(d_is_negative(a->dst_h_dentry)))
+ goto out;
+ h_inode = d_inode(a->dst_h_dentry);
+ if (h_inode->i_nlink)
+ err = au_may_del(a->dst_dentry, a->btgt,
+ a->dst_h_parent, isdir);
+ }
+
+out:
+ if (unlikely(err == -ENOENT || err == -EEXIST))
+ err = -EIO;
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * locking order
+ * (VFS)
+ * - src_dir and dir by lock_rename()
+ * - inode if exitsts
+ * (aufs)
+ * - lock all
+ * + src_dentry and dentry by aufs_read_and_write_lock2() which calls,
+ * + si_read_lock
+ * + di_write_lock2_child()
+ * + di_write_lock_child()
+ * + ii_write_lock_child()
+ * + di_write_lock_child2()
+ * + ii_write_lock_child2()
+ * + src_parent and parent
+ * + di_write_lock_parent()
+ * + ii_write_lock_parent()
+ * + di_write_lock_parent2()
+ * + ii_write_lock_parent2()
+ * + lower src_dir and dir by vfsub_lock_rename()
+ * + verify the every relationships between child and parent. if any
+ * of them failed, unlock all and return -EBUSY.
+ */
+static void au_ren_unlock(struct au_ren_args *a)
+{
+ vfsub_unlock_rename(a->src_h_parent, a->src_hdir,
+ a->dst_h_parent, a->dst_hdir);
+ if (au_ftest_ren(a->flags, MNT_WRITE))
+ vfsub_mnt_drop_write(au_br_mnt(a->br));
+}
+
+static int au_ren_lock(struct au_ren_args *a)
+{
+ int err;
+ unsigned int udba;
+
+ err = 0;
+ a->src_h_parent = au_h_dptr(a->src_parent, a->btgt);
+ a->src_hdir = au_hi(a->src_dir, a->btgt);
+ a->dst_h_parent = au_h_dptr(a->dst_parent, a->btgt);
+ a->dst_hdir = au_hi(a->dst_dir, a->btgt);
+
+ err = vfsub_mnt_want_write(au_br_mnt(a->br));
+ if (unlikely(err))
+ goto out;
+ au_fset_ren(a->flags, MNT_WRITE);
+ a->h_trap = vfsub_lock_rename(a->src_h_parent, a->src_hdir,
+ a->dst_h_parent, a->dst_hdir);
+ udba = au_opt_udba(a->src_dentry->d_sb);
+ if (unlikely(a->src_hdir->hi_inode != d_inode(a->src_h_parent)
+ || a->dst_hdir->hi_inode != d_inode(a->dst_h_parent)))
+ err = au_busy_or_stale();
+ if (!err && au_dbstart(a->src_dentry) == a->btgt)
+ err = au_h_verify(a->src_h_dentry, udba,
+ d_inode(a->src_h_parent), a->src_h_parent,
+ a->br);
+ if (!err && au_dbstart(a->dst_dentry) == a->btgt)
+ err = au_h_verify(a->dst_h_dentry, udba,
+ d_inode(a->dst_h_parent), a->dst_h_parent,
+ a->br);
+ if (!err)
+ goto out; /* success */
+
+ err = au_busy_or_stale();
+ au_ren_unlock(a);
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void au_ren_refresh_dir(struct au_ren_args *a)
+{
+ struct inode *dir;
+
+ dir = a->dst_dir;
+ dir->i_version++;
+ if (au_ftest_ren(a->flags, ISDIR)) {
+ /* is this updating defined in POSIX? */
+ au_cpup_attr_timesizes(a->src_inode);
+ au_cpup_attr_nlink(dir, /*force*/1);
+ }
+
+ au_dir_ts(dir, a->btgt);
+
+ if (au_ftest_ren(a->flags, ISSAMEDIR))
+ return;
+
+ dir = a->src_dir;
+ dir->i_version++;
+ if (au_ftest_ren(a->flags, ISDIR))
+ au_cpup_attr_nlink(dir, /*force*/1);
+ au_dir_ts(dir, a->btgt);
+}
+
+static void au_ren_refresh(struct au_ren_args *a)
+{
+ aufs_bindex_t bend, bindex;
+ struct dentry *d, *h_d;
+ struct inode *i, *h_i;
+ struct super_block *sb;
+
+ d = a->dst_dentry;
+ d_drop(d);
+ if (a->h_dst)
+ /* already dget-ed by au_ren_or_cpup() */
+ au_set_h_dptr(d, a->btgt, a->h_dst);
+
+ i = a->dst_inode;
+ if (i) {
+ if (!au_ftest_ren(a->flags, ISDIR))
+ vfsub_drop_nlink(i);
+ else {
+ vfsub_dead_dir(i);
+ au_cpup_attr_timesizes(i);
+ }
+ au_update_dbrange(d, /*do_put_zero*/1);
+ } else {
+ bend = a->btgt;
+ for (bindex = au_dbstart(d); bindex < bend; bindex++)
+ au_set_h_dptr(d, bindex, NULL);
+ bend = au_dbend(d);
+ for (bindex = a->btgt + 1; bindex <= bend; bindex++)
+ au_set_h_dptr(d, bindex, NULL);
+ au_update_dbrange(d, /*do_put_zero*/0);
+ }
+
+ d = a->src_dentry;
+ au_set_dbwh(d, -1);
+ bend = au_dbend(d);
+ for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
+ h_d = au_h_dptr(d, bindex);
+ if (h_d)
+ au_set_h_dptr(d, bindex, NULL);
+ }
+ au_set_dbend(d, a->btgt);
+
+ sb = d->d_sb;
+ i = a->src_inode;
+ if (au_opt_test(au_mntflags(sb), PLINK) && au_plink_test(i))
+ return; /* success */
+
+ bend = au_ibend(i);
+ for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
+ h_i = au_h_iptr(i, bindex);
+ if (h_i) {
+ au_xino_write(sb, bindex, h_i->i_ino, /*ino*/0);
+ /* ignore this error */
+ au_set_h_iptr(i, bindex, NULL, 0);
+ }
+ }
+ au_set_ibend(i, a->btgt);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* mainly for link(2) and rename(2) */
+int au_wbr(struct dentry *dentry, aufs_bindex_t btgt)
+{
+ aufs_bindex_t bdiropq, bwh;
+ struct dentry *parent;
+ struct au_branch *br;
+
+ parent = dentry->d_parent;
+ IMustLock(d_inode(parent)); /* dir is locked */
+
+ bdiropq = au_dbdiropq(parent);
+ bwh = au_dbwh(dentry);
+ br = au_sbr(dentry->d_sb, btgt);
+ if (au_br_rdonly(br)
+ || (0 <= bdiropq && bdiropq < btgt)
+ || (0 <= bwh && bwh < btgt))
+ btgt = -1;
+
+ AuDbg("btgt %d\n", btgt);
+ return btgt;
+}
+
+/* sets src_bstart, dst_bstart and btgt */
+static int au_ren_wbr(struct au_ren_args *a)
+{
+ int err;
+ struct au_wr_dir_args wr_dir_args = {
+ /* .force_btgt = -1, */
+ .flags = AuWrDir_ADD_ENTRY
+ };
+
+ a->src_bstart = au_dbstart(a->src_dentry);
+ a->dst_bstart = au_dbstart(a->dst_dentry);
+ if (au_ftest_ren(a->flags, ISDIR))
+ au_fset_wrdir(wr_dir_args.flags, ISDIR);
+ wr_dir_args.force_btgt = a->src_bstart;
+ if (a->dst_inode && a->dst_bstart < a->src_bstart)
+ wr_dir_args.force_btgt = a->dst_bstart;
+ wr_dir_args.force_btgt = au_wbr(a->dst_dentry, wr_dir_args.force_btgt);
+ err = au_wr_dir(a->dst_dentry, a->src_dentry, &wr_dir_args);
+ a->btgt = err;
+
+ return err;
+}
+
+static void au_ren_dt(struct au_ren_args *a)
+{
+ a->h_path.dentry = a->src_h_parent;
+ au_dtime_store(a->src_dt + AuPARENT, a->src_parent, &a->h_path);
+ if (!au_ftest_ren(a->flags, ISSAMEDIR)) {
+ a->h_path.dentry = a->dst_h_parent;
+ au_dtime_store(a->dst_dt + AuPARENT, a->dst_parent, &a->h_path);
+ }
+
+ au_fclr_ren(a->flags, DT_DSTDIR);
+ if (!au_ftest_ren(a->flags, ISDIR))
+ return;
+
+ a->h_path.dentry = a->src_h_dentry;
+ au_dtime_store(a->src_dt + AuCHILD, a->src_dentry, &a->h_path);
+ if (d_is_positive(a->dst_h_dentry)) {
+ au_fset_ren(a->flags, DT_DSTDIR);
+ a->h_path.dentry = a->dst_h_dentry;
+ au_dtime_store(a->dst_dt + AuCHILD, a->dst_dentry, &a->h_path);
+ }
+}
+
+static void au_ren_rev_dt(int err, struct au_ren_args *a)
+{
+ struct dentry *h_d;
+ struct mutex *h_mtx;
+
+ au_dtime_revert(a->src_dt + AuPARENT);
+ if (!au_ftest_ren(a->flags, ISSAMEDIR))
+ au_dtime_revert(a->dst_dt + AuPARENT);
+
+ if (au_ftest_ren(a->flags, ISDIR) && err != -EIO) {
+ h_d = a->src_dt[AuCHILD].dt_h_path.dentry;
+ h_mtx = &d_inode(h_d)->i_mutex;
+ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
+ au_dtime_revert(a->src_dt + AuCHILD);
+ mutex_unlock(h_mtx);
+
+ if (au_ftest_ren(a->flags, DT_DSTDIR)) {
+ h_d = a->dst_dt[AuCHILD].dt_h_path.dentry;
+ h_mtx = &d_inode(h_d)->i_mutex;
+ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
+ au_dtime_revert(a->dst_dt + AuCHILD);
+ mutex_unlock(h_mtx);
+ }
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+int aufs_rename(struct inode *_src_dir, struct dentry *_src_dentry,
+ struct inode *_dst_dir, struct dentry *_dst_dentry)
+{
+ int err, flags;
+ /* reduce stack space */
+ struct au_ren_args *a;
+
+ AuDbg("%pd, %pd\n", _src_dentry, _dst_dentry);
+ IMustLock(_src_dir);
+ IMustLock(_dst_dir);
+
+ err = -ENOMEM;
+ BUILD_BUG_ON(sizeof(*a) > PAGE_SIZE);
+ a = kzalloc(sizeof(*a), GFP_NOFS);
+ if (unlikely(!a))
+ goto out;
+
+ a->src_dir = _src_dir;
+ a->src_dentry = _src_dentry;
+ a->src_inode = NULL;
+ if (d_really_is_positive(a->src_dentry))
+ a->src_inode = d_inode(a->src_dentry);
+ a->src_parent = a->src_dentry->d_parent; /* dir inode is locked */
+ a->dst_dir = _dst_dir;
+ a->dst_dentry = _dst_dentry;
+ a->dst_inode = NULL;
+ if (d_really_is_positive(a->dst_dentry))
+ a->dst_inode = d_inode(a->dst_dentry);
+ a->dst_parent = a->dst_dentry->d_parent; /* dir inode is locked */
+ if (a->dst_inode) {
+ IMustLock(a->dst_inode);
+ au_igrab(a->dst_inode);
+ }
+
+ err = -ENOTDIR;
+ flags = AuLock_FLUSH | AuLock_NOPLM | AuLock_GEN;
+ if (d_is_dir(a->src_dentry)) {
+ au_fset_ren(a->flags, ISDIR);
+ if (unlikely(d_really_is_positive(a->dst_dentry)
+ && !d_is_dir(a->dst_dentry)))
+ goto out_free;
+ err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
+ AuLock_DIR | flags);
+ } else
+ err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
+ flags);
+ if (unlikely(err))
+ goto out_free;
+
+ err = au_d_hashed_positive(a->src_dentry);
+ if (unlikely(err))
+ goto out_unlock;
+ err = -ENOENT;
+ if (a->dst_inode) {
+ /*
+ * If it is a dir, VFS unhash dst_dentry before this
+ * function. It means we cannot rely upon d_unhashed().
+ */
+ if (unlikely(!a->dst_inode->i_nlink))
+ goto out_unlock;
+ if (!S_ISDIR(a->dst_inode->i_mode)) {
+ err = au_d_hashed_positive(a->dst_dentry);
+ if (unlikely(err))
+ goto out_unlock;
+ } else if (unlikely(IS_DEADDIR(a->dst_inode)))
+ goto out_unlock;
+ } else if (unlikely(d_unhashed(a->dst_dentry)))
+ goto out_unlock;
+
+ /*
+ * is it possible?
+ * yes, it happend (in linux-3.3-rcN) but I don't know why.
+ * there may exist a problem somewhere else.
+ */
+ err = -EINVAL;
+ if (unlikely(d_inode(a->dst_parent) == d_inode(a->src_dentry)))
+ goto out_unlock;
+
+ au_fset_ren(a->flags, ISSAMEDIR); /* temporary */
+ di_write_lock_parent(a->dst_parent);
+
+ /* which branch we process */
+ err = au_ren_wbr(a);
+ if (unlikely(err < 0))
+ goto out_parent;
+ a->br = au_sbr(a->dst_dentry->d_sb, a->btgt);
+ a->h_path.mnt = au_br_mnt(a->br);
+
+ /* are they available to be renamed */
+ err = au_ren_may_dir(a);
+ if (unlikely(err))
+ goto out_children;
+
+ /* prepare the writable parent dir on the same branch */
+ if (a->dst_bstart == a->btgt) {
+ au_fset_ren(a->flags, WHDST);
+ } else {
+ err = au_cpup_dirs(a->dst_dentry, a->btgt);
+ if (unlikely(err))
+ goto out_children;
+ }
+
+ if (a->src_dir != a->dst_dir) {
+ /*
+ * this temporary unlock is safe,
+ * because both dir->i_mutex are locked.
+ */
+ di_write_unlock(a->dst_parent);
+ di_write_lock_parent(a->src_parent);
+ err = au_wr_dir_need_wh(a->src_dentry,
+ au_ftest_ren(a->flags, ISDIR),
+ &a->btgt);
+ di_write_unlock(a->src_parent);
+ di_write_lock2_parent(a->src_parent, a->dst_parent, /*isdir*/1);
+ au_fclr_ren(a->flags, ISSAMEDIR);
+ } else
+ err = au_wr_dir_need_wh(a->src_dentry,
+ au_ftest_ren(a->flags, ISDIR),
+ &a->btgt);
+ if (unlikely(err < 0))
+ goto out_children;
+ if (err)
+ au_fset_ren(a->flags, WHSRC);
+
+ /* cpup src */
+ if (a->src_bstart != a->btgt) {
+ struct au_pin pin;
+
+ err = au_pin(&pin, a->src_dentry, a->btgt,
+ au_opt_udba(a->src_dentry->d_sb),
+ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
+ if (!err) {
+ struct au_cp_generic cpg = {
+ .dentry = a->src_dentry,
+ .bdst = a->btgt,
+ .bsrc = a->src_bstart,
+ .len = -1,
+ .pin = &pin,
+ .flags = AuCpup_DTIME | AuCpup_HOPEN
+ };
+ AuDebugOn(au_dbstart(a->src_dentry) != a->src_bstart);
+ err = au_sio_cpup_simple(&cpg);
+ au_unpin(&pin);
+ }
+ if (unlikely(err))
+ goto out_children;
+ a->src_bstart = a->btgt;
+ a->src_h_dentry = au_h_dptr(a->src_dentry, a->btgt);
+ au_fset_ren(a->flags, WHSRC);
+ }
+
+ /* lock them all */
+ err = au_ren_lock(a);
+ if (unlikely(err))
+ /* leave the copied-up one */
+ goto out_children;
+
+ if (!au_opt_test(au_mntflags(a->dst_dir->i_sb), UDBA_NONE))
+ err = au_may_ren(a);
+ else if (unlikely(a->dst_dentry->d_name.len > AUFS_MAX_NAMELEN))
+ err = -ENAMETOOLONG;
+ if (unlikely(err))
+ goto out_hdir;
+
+ /* store timestamps to be revertible */
+ au_ren_dt(a);
+
+ /* here we go */
+ err = do_rename(a);
+ if (unlikely(err))
+ goto out_dt;
+
+ /* update dir attributes */
+ au_ren_refresh_dir(a);
+
+ /* dput/iput all lower dentries */
+ au_ren_refresh(a);
+
+ goto out_hdir; /* success */
+
+out_dt:
+ au_ren_rev_dt(err, a);
+out_hdir:
+ au_ren_unlock(a);
+out_children:
+ au_nhash_wh_free(&a->whlist);
+ if (err && a->dst_inode && a->dst_bstart != a->btgt) {
+ AuDbg("bstart %d, btgt %d\n", a->dst_bstart, a->btgt);
+ au_set_h_dptr(a->dst_dentry, a->btgt, NULL);
+ au_set_dbstart(a->dst_dentry, a->dst_bstart);
+ }
+out_parent:
+ if (!err)
+ d_move(a->src_dentry, a->dst_dentry);
+ else {
+ au_update_dbstart(a->dst_dentry);
+ if (!a->dst_inode)
+ d_drop(a->dst_dentry);
+ }
+ if (au_ftest_ren(a->flags, ISSAMEDIR))
+ di_write_unlock(a->dst_parent);
+ else
+ di_write_unlock2(a->src_parent, a->dst_parent);
+out_unlock:
+ aufs_read_and_write_unlock2(a->dst_dentry, a->src_dentry);
+out_free:
+ iput(a->dst_inode);
+ if (a->thargs)
+ au_whtmp_rmdir_free(a->thargs);
+ kfree(a);
+out:
+ AuTraceErr(err);
+ return err;
+}