| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1211340189-11813-16-git-send-email-hooanon05@yahoo.co.jp>
Date: Wed, 21 May 2008 12:22:45 +0900
From: hooanon05@...oo.co.jp
To: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: Junjiro Okajima <hooanon05@...oo.co.jp>
Subject: [AUFS PATCH v2.6.26-rc2-mm1 15/39] aufs whiteout
From: Junjiro Okajima <hooanon05@...oo.co.jp>
initial commit
whiteout for logical deletion and opaque directory
Signed-off-by: Junjiro Okajima <hooanon05@...oo.co.jp>
---
fs/aufs/whout.c | 1026 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/aufs/whout.h | 138 ++++++++
2 files changed, 1164 insertions(+), 0 deletions(-)
create mode 100644 fs/aufs/whout.c
create mode 100644 fs/aufs/whout.h
diff --git a/fs/aufs/whout.c b/fs/aufs/whout.c
new file mode 100644
index 0000000..4b18a3f
--- /dev/null
+++ b/fs/aufs/whout.c
@@ -0,0 +1,1026 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * whiteout for logical deletion and opaque directory
+ */
+
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include "aufs.h"
+
+#define WH_MASK S_IRUGO
+
+/* If a directory contains this file, then it is opaque. We start with the
+ * .wh. flag so that it is blocked by lookup.
+ */
+static struct qstr diropq_name = {
+ .name = AUFS_WH_DIROPQ,
+ .len = sizeof(AUFS_WH_DIROPQ) - 1
+};
+
+/*
+ * generate whiteout name, which is NOT terminated by NULL.
+ * @name: original d_name.name
+ * @len: original d_name.len
+ * @wh: whiteout qstr
+ * returns zero when succeeds, otherwise error.
+ * succeeded value as wh->name should be freed by au_wh_name_free().
+ */
+int au_wh_name_alloc(const char *name, int len, struct qstr *wh)
+{
+ char *p;
+
+ AuDebugOn(!name || !len || !wh);
+
+ if (unlikely(len > PATH_MAX - AUFS_WH_PFX_LEN))
+ return -ENAMETOOLONG;
+
+ wh->len = len + AUFS_WH_PFX_LEN;
+ p = kmalloc(wh->len, GFP_KERNEL);
+ wh->name = p;
+ if (p) {
+ memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
+ memcpy(p + AUFS_WH_PFX_LEN, name, len);
+ /* smp_mb(); */
+ return 0;
+ }
+ return -ENOMEM;
+}
+
+void au_wh_name_free(struct qstr *wh)
+{
+ AuDebugOn(!wh || !wh->name);
+ kfree(wh->name);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * test if the @wh_name exists under @h_parent.
+ * @try_sio specifies the necessary of super-io.
+ */
+int au_wh_test(struct dentry *h_parent, struct qstr *wh_name, int try_sio,
+ struct au_ndx *ndx)
+{
+ int err;
+ struct dentry *wh_dentry;
+ struct inode *h_dir;
+ unsigned int flags;
+
+ LKTRTrace("%.*s/%.*s, ndx{%p, 0x%x}\n", AuDLNPair(h_parent),
+ wh_name->len, wh_name->name, ndx->nfsmnt, ndx->flags);
+ h_dir = h_parent->d_inode;
+ AuDebugOn(!S_ISDIR(h_dir->i_mode));
+
+ flags = 0;
+ if (ndx && ndx->nd) {
+ flags = ndx->nd->flags;
+ ndx->nd->flags &= ~(LOOKUP_OPEN | LOOKUP_CREATE);
+ }
+
+ if (!try_sio)
+ wh_dentry = au_lkup_one(wh_name->name, h_parent,
+ wh_name->len, ndx);
+ else
+ wh_dentry = au_sio_lkup_one(wh_name->name, h_parent,
+ wh_name->len, ndx);
+ if (flags)
+ ndx->nd->flags = flags;
+ err = PTR_ERR(wh_dentry);
+ if (IS_ERR(wh_dentry))
+ goto out;
+
+ err = 0;
+ if (!wh_dentry->d_inode)
+ goto out_wh; /* success */
+
+ err = 1;
+ if (S_ISREG(wh_dentry->d_inode->i_mode))
+ goto out_wh; /* success */
+
+ err = -EIO;
+ AuIOErr("%.*s Invalid whiteout entry type 0%o.\n",
+ AuDLNPair(wh_dentry), wh_dentry->d_inode->i_mode);
+
+ out_wh:
+ dput(wh_dentry);
+ out:
+ AuTraceErr(err);
+ return err;
+}
+
+/*
+ * test if the @h_dentry sets opaque or not.
+ */
+int au_diropq_test(struct dentry *h_dentry, struct au_ndx *ndx)
+{
+ int err, try_sio;
+ struct inode *h_dir;
+
+ LKTRTrace("dentry %.*s\n", AuDLNPair(h_dentry));
+ h_dir = h_dentry->d_inode;
+ AuDebugOn(!S_ISDIR(h_dir->i_mode));
+
+ try_sio = au_test_h_perm_sio(h_dir, MAY_EXEC,
+ au_ftest_ndx(ndx->flags, DLGT));
+ err = au_wh_test(h_dentry, &diropq_name, try_sio, ndx);
+ AuTraceErr(err);
+ return err;
+}
+
+/*
+ * returns a negative dentry whose name is unique and temporary.
+ */
+struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct qstr *prefix,
+ struct au_ndx *ndx)
+{
+#define HEX_LEN 4
+ struct dentry *dentry;
+ int len, i;
+ char defname[AUFS_WH_PFX_LEN * 2 + DNAME_INLINE_LEN_MIN + 1
+ + HEX_LEN + 1], *name, *p;
+ static unsigned char cnt;
+
+ LKTRTrace("hp %.*s, prefix %.*s\n",
+ AuDLNPair(h_parent), prefix->len, prefix->name);
+ AuDebugOn(!h_parent->d_inode);
+
+ name = defname;
+ len = sizeof(defname) - DNAME_INLINE_LEN_MIN + prefix->len - 1;
+ if (unlikely(prefix->len > DNAME_INLINE_LEN_MIN)) {
+ dentry = ERR_PTR(-ENAMETOOLONG);
+ if (unlikely(len >= PATH_MAX))
+ goto out;
+ dentry = ERR_PTR(-ENOMEM);
+ name = kmalloc(len + 1, GFP_KERNEL);
+ if (unlikely(!name))
+ goto out;
+ }
+
+ /* doubly whiteout-ed */
+ memcpy(name, AUFS_WH_PFX AUFS_WH_PFX, AUFS_WH_PFX_LEN * 2);
+ p = name + AUFS_WH_PFX_LEN * 2;
+ memcpy(p, prefix->name, prefix->len);
+ p += prefix->len;
+ *p++ = '.';
+ AuDebugOn(name + len + 1 - p <= HEX_LEN);
+
+ for (i = 0; i < 3; i++) {
+ sprintf(p, "%.*d", HEX_LEN, cnt++);
+ dentry = au_sio_lkup_one(name, h_parent, len, ndx);
+ if (IS_ERR(dentry) || !dentry->d_inode)
+ goto out_name;
+ dput(dentry);
+ }
+ /* AuWarn("could not get random name\n"); */
+ dentry = ERR_PTR(-EEXIST);
+ AuDbg("%.*s\n", len, name);
+ BUG();
+
+ out_name:
+ if (unlikely(name != defname))
+ kfree(name);
+ out:
+ AuTraceErrPtr(dentry);
+ return dentry;
+#undef HEX_LEN
+}
+
+/*
+ * rename the @dentry of @bindex to the whiteouted temporary name.
+ */
+int au_whtmp_ren(struct inode *dir, struct dentry *dentry, aufs_bindex_t bindex,
+ int noself)
+{
+ int err, dlgt;
+ struct inode *h_dir;
+ struct dentry *h_dentry, *h_parent, *tmp_dentry;
+ struct super_block *sb;
+ unsigned int mnt_flags;
+ struct au_hin_ignore ign;
+ struct vfsub_args vargs;
+ struct au_ndx ndx = {
+ .flags = 0,
+ .nd = NULL,
+ /* .br = NULL */
+ };
+
+ LKTRTrace("%.*s, b%d\n", AuDLNPair(dentry), bindex);
+ h_dentry = au_h_dptr(dentry, bindex);
+ AuDebugOn(!h_dentry || !h_dentry->d_inode);
+ h_parent = h_dentry->d_parent; /* dir inode is locked */
+ h_dir = h_parent->d_inode;
+ IMustLock(h_dir);
+
+ sb = dentry->d_sb;
+ mnt_flags = au_mntflags(sb);
+ dlgt = !!au_opt_test_dlgt(mnt_flags);
+ if (unlikely(dlgt))
+ au_fset_ndx(ndx.flags, DLGT);
+ ndx.nfsmnt = au_nfsmnt(sb, bindex);
+ tmp_dentry = au_whtmp_lkup(h_parent, &h_dentry->d_name, &ndx);
+ err = PTR_ERR(tmp_dentry);
+ if (!IS_ERR(tmp_dentry)) {
+ /* under the same dir, no need to lock_rename() */
+ vfsub_args_init(&vargs, &ign, dlgt, 0);
+ AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
+ if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY) && !noself))
+ vfsub_ign_hinode(&vargs, IN_MOVE_SELF,
+ au_hi(dentry->d_inode, bindex));
+ err = vfsub_rename(h_dir, h_dentry, h_dir, tmp_dentry, &vargs);
+ AuTraceErr(err);
+ dput(tmp_dentry);
+ }
+
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int do_unlink_wh(struct inode *h_dir, struct dentry *wh_dentry,
+ struct inode *dir, int dlgt)
+{
+ struct vfsub_args vargs;
+
+ LKTRTrace("hi%lu, wh %.*s\n", h_dir->i_ino, AuDLNPair(wh_dentry));
+ AuDebugOn(!wh_dentry->d_inode || !S_ISREG(wh_dentry->d_inode->i_mode));
+
+ /*
+ * forces superio when the dir has a sticky bit.
+ * this may be a violation of unix fs semantics.
+ */
+ vfsub_args_init(&vargs, NULL, dlgt,
+ (h_dir->i_mode & S_ISVTX)
+ && wh_dentry->d_inode->i_uid != current->fsuid);
+ return vfsub_unlink(h_dir, wh_dentry, &vargs);
+}
+
+int au_wh_unlink_dentry(struct inode *h_dir, struct dentry *wh_dentry,
+ struct dentry *dentry, struct inode *dir, int dlgt)
+{
+ int err;
+
+ LKTRTrace("hi%lu, wh %.*s, d %p\n", h_dir->i_ino,
+ AuDLNPair(wh_dentry), dentry);
+ AuDebugOn((dentry && au_dbwh(dentry) < 0)
+ || !wh_dentry->d_inode
+ || !S_ISREG(wh_dentry->d_inode->i_mode));
+
+ err = do_unlink_wh(h_dir, wh_dentry, dir, dlgt);
+ if (!err && dentry)
+ au_set_dbwh(dentry, -1);
+
+ AuTraceErr(err);
+ return err;
+}
+
+static int unlink_wh_name(struct dentry *h_parent, struct qstr *wh,
+ struct inode *dir, struct au_ndx *ndx)
+{
+ int err;
+ struct inode *h_dir;
+ struct dentry *h_dentry;
+
+ LKTRTrace("%.*s/%.*s\n", AuDLNPair(h_parent), AuLNPair(wh));
+ h_dir = h_parent->d_inode;
+
+ /* au_test_h_perm() is already done */
+ h_dentry = au_lkup_one(wh->name, h_parent, wh->len, ndx);
+ if (!IS_ERR(h_dentry)) {
+ err = 0;
+ if (h_dentry->d_inode && S_ISREG(h_dentry->d_inode->i_mode))
+ err = do_unlink_wh(h_dir, h_dentry, dir,
+ au_ftest_ndx(ndx->flags, DLGT));
+ dput(h_dentry);
+ } else
+ err = PTR_ERR(h_dentry);
+
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void clean_wh(struct inode *h_dir, struct dentry *wh)
+{
+ int err;
+ struct vfsub_args vargs;
+
+ AuTraceEnter();
+
+ if (wh->d_inode) {
+ vfsub_args_init(&vargs, NULL, 0, 0);
+ err = vfsub_unlink(h_dir, wh, &vargs);
+ if (unlikely(err))
+ AuWarn("failed unlink %.*s (%d), ignored.\n",
+ AuDLNPair(wh), err);
+ }
+}
+
+static void clean_plink(struct inode *h_dir, struct dentry *plink)
+{
+ int err;
+ struct vfsub_args vargs;
+
+ AuTraceEnter();
+
+ if (plink->d_inode) {
+ vfsub_args_init(&vargs, NULL, 0, 0);
+ err = vfsub_rmdir(h_dir, plink, &vargs);
+ if (unlikely(err))
+ AuWarn("failed rmdir %.*s (%d), ignored.\n",
+ AuDLNPair(plink), err);
+ }
+}
+
+static int test_linkable(struct inode *h_dir)
+{
+ if (h_dir->i_op && h_dir->i_op->link)
+ return 0;
+ return -ENOSYS;
+}
+
+static int plink_dir(struct inode *h_dir, struct dentry *plink)
+{
+ int err;
+
+ err = -EEXIST;
+ if (!plink->d_inode) {
+ int mode = S_IRWXU;
+ if (unlikely(au_test_nfs(plink->d_sb)))
+ mode |= S_IXUGO;
+ err = vfsub_mkdir(h_dir, plink, mode, /*dlgt*/0);
+ } else if (S_ISDIR(plink->d_inode->i_mode))
+ err = 0;
+ else
+ AuErr("unknown %.*s exists\n", AuDLNPair(plink));
+
+ return err;
+}
+
+/*
+ * initialize the whiteout base file/dir for @br.
+ */
+int au_wh_init(struct dentry *h_root, struct au_branch *br,
+ struct vfsmount *nfsmnt, struct super_block *sb)
+{
+ int err;
+ struct dentry *wh, *plink;
+ struct inode *h_dir;
+ static struct qstr base_name[] = {
+ {
+ .name = AUFS_WH_BASENAME,
+ .len = sizeof(AUFS_WH_BASENAME) - 1
+ },
+ {
+ .name = AUFS_WH_PLINKDIR,
+ .len = sizeof(AUFS_WH_PLINKDIR) - 1
+ }
+ };
+ struct au_ndx ndx = {
+ .nfsmnt = nfsmnt,
+ .flags = 0, /* always no dlgt */
+ .nd = NULL,
+ /* .br = NULL */
+ };
+ const int do_plink = au_opt_test(au_mntflags(sb), PLINK);
+
+ LKTRTrace("nfsmnt %p\n", nfsmnt);
+ BrWhMustWriteLock(br);
+ SiMustWriteLock(sb);
+ h_dir = h_root->d_inode;
+
+ /* doubly whiteouted */
+ wh = au_wh_lkup(h_root, base_name + 0, &ndx);
+ err = PTR_ERR(wh);
+ if (IS_ERR(wh))
+ goto out;
+ AuDebugOn(br->br_wh && br->br_wh != wh);
+
+ plink = au_wh_lkup(h_root, base_name + 1, &ndx);
+ err = PTR_ERR(plink);
+ if (IS_ERR(plink))
+ goto out_dput_wh;
+ AuDebugOn(br->br_plink && br->br_plink != plink);
+
+ dput(br->br_wh);
+ dput(br->br_plink);
+ br->br_wh = NULL;
+ br->br_plink = NULL;
+
+ err = 0;
+ switch (br->br_perm) {
+ case AuBr_RR:
+ case AuBr_RO:
+ case AuBr_RRWH:
+ case AuBr_ROWH:
+ clean_wh(h_dir, wh);
+ clean_plink(h_dir, plink);
+ break;
+
+ case AuBr_RWNoLinkWH:
+ clean_wh(h_dir, wh);
+ if (do_plink) {
+ err = test_linkable(h_dir);
+ if (unlikely(err))
+ goto out_nolink;
+
+ err = plink_dir(h_dir, plink);
+ if (unlikely(err))
+ goto out_err;
+ br->br_plink = dget(plink);
+ } else
+ clean_plink(h_dir, plink);
+ break;
+
+ case AuBr_RW:
+ /*
+ * for the moment, aufs supports the branch filesystem
+ * which does not support link(2).
+ * testing on FAT which does not support i_op->setattr() fully
+ * either, copyup failed.
+ * finally, such filesystem will not be used as the writable
+ * branch.
+ */
+ err = test_linkable(h_dir);
+ if (unlikely(err))
+ goto out_nolink;
+
+ err = -EEXIST;
+ if (!wh->d_inode)
+ err = au_h_create(h_dir, wh, WH_MASK, /*dlgt*/0,
+ /*nd*/NULL, nfsmnt);
+ else if (S_ISREG(wh->d_inode->i_mode))
+ err = 0;
+ else
+ AuErr("unknown %.*s/%.*s exists\n",
+ AuDLNPair(h_root), AuDLNPair(wh));
+ if (unlikely(err))
+ goto out_err;
+
+ if (do_plink) {
+ err = plink_dir(h_dir, plink);
+ if (unlikely(err))
+ goto out_err;
+ br->br_plink = dget(plink);
+ } else
+ clean_plink(h_dir, plink);
+ br->br_wh = dget(wh);
+ break;
+
+ default:
+ BUG();
+ }
+
+ out_dput:
+ dput(plink);
+ out_dput_wh:
+ dput(wh);
+ out:
+ AuTraceErr(err);
+ return err;
+ out_nolink:
+ AuErr("%.*s doesn't support link(2), use noplink and rw+nolwh\n",
+ AuDLNPair(h_root));
+ goto out_dput;
+ out_err:
+ AuErr("an error(%d) on the writable branch %.*s(%s)\n",
+ err, AuDLNPair(h_root), au_sbtype(h_root->d_sb));
+ goto out_dput;
+}
+
+struct reinit_br_wh {
+ struct super_block *sb;
+ struct au_branch *br;
+};
+
+static void reinit_br_wh(void *arg)
+{
+ int err;
+ struct reinit_br_wh *a = arg;
+ struct inode *h_dir, *dir;
+ struct dentry *h_root;
+ aufs_bindex_t bindex;
+ struct vfsub_args vargs;
+
+ AuTraceEnter();
+ AuDebugOn(!a->br->br_wh || !a->br->br_wh->d_inode || current->fsuid);
+
+ err = 0;
+ /* big aufs lock */
+ si_write_lock(a->sb);
+ if (unlikely(!au_br_writable(a->br->br_perm)))
+ goto out;
+ bindex = au_br_index(a->sb, a->br->br_id);
+ if (unlikely(bindex < 0))
+ goto out;
+
+ dir = a->sb->s_root->d_inode;
+ h_root = dget_parent(a->br->br_wh);
+ h_dir = h_root->d_inode;
+ AuDebugOn(!h_dir->i_op || !h_dir->i_op->link);
+ vfsub_args_init(&vargs, NULL, /*dlgt*/0, 0);
+ au_hdir_lock(h_dir, dir, bindex);
+ /* todo: revalidate h_wh? */
+ br_wh_write_lock(a->br);
+ err = vfsub_unlink(h_dir, a->br->br_wh, &vargs);
+ dput(a->br->br_wh);
+ a->br->br_wh = NULL;
+ if (!err)
+ err = au_wh_init(h_root, a->br, au_do_nfsmnt(a->br->br_mnt),
+ a->sb);
+ br_wh_write_unlock(a->br);
+ au_hdir_unlock(h_dir, dir, bindex);
+ dput(h_root);
+
+ out:
+ atomic_dec_return(&a->br->br_wh_running);
+ au_br_put(a->br);
+ si_write_unlock(a->sb);
+ kfree(arg);
+ if (unlikely(err))
+ AuIOErr("err %d\n", err);
+}
+
+static void kick_reinit_br_wh(struct super_block *sb, struct au_branch *br)
+{
+ int do_dec, wkq_err;
+ struct reinit_br_wh *arg;
+
+ do_dec = 1;
+ if (atomic_inc_return(&br->br_wh_running) != 1)
+ goto out;
+
+ /* ignore ENOMEM */
+ arg = kmalloc(sizeof(*arg), GFP_TEMPORARY);
+ if (arg) {
+ /*
+ * dec(wh_running), kfree(arg) and au_br_put()
+ * in reinit function
+ */
+ arg->sb = sb;
+ arg->br = br;
+ au_br_get(br);
+ wkq_err = au_wkq_nowait(reinit_br_wh, arg, sb, /*dlgt*/0);
+ if (unlikely(wkq_err)) {
+ atomic_dec_return(&br->br_wh_running);
+ au_br_put(br);
+ kfree(arg);
+ }
+ do_dec = 0;
+ }
+
+ out:
+ if (do_dec)
+ atomic_dec_return(&br->br_wh_running);
+}
+
+/*
+ * create the whiteout @wh.
+ */
+static int link_or_create_wh(struct dentry *wh, struct super_block *sb,
+ aufs_bindex_t bindex, struct inode *dir)
+{
+ int err, dlgt;
+ struct au_branch *br;
+ struct dentry *h_parent;
+ struct inode *h_dir;
+
+ LKTRTrace("%.*s\n", AuDLNPair(wh));
+ SiMustReadLock(sb);
+ h_parent = wh->d_parent; /* dir inode is locked */
+ h_dir = h_parent->d_inode;
+ IMustLock(h_dir);
+
+ dlgt = !!au_opt_test_dlgt(au_mntflags(sb));
+ br = au_sbr(sb, bindex);
+ br_wh_read_lock(br);
+ if (br->br_wh) {
+ err = vfsub_link(br->br_wh, h_dir, wh, dlgt);
+ if (!err || err != -EMLINK)
+ goto out;
+
+ /* link count full. re-initialize br_wh. */
+ kick_reinit_br_wh(sb, br);
+ }
+
+ /* return this error in this context */
+ err = au_h_create(h_dir, wh, WH_MASK, dlgt, /*nd*/NULL,
+ au_do_nfsmnt(br->br_mnt));
+
+ out:
+ br_wh_read_unlock(br);
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * create or remove the diropq.
+ */
+static struct dentry *do_diropq(struct dentry *dentry, aufs_bindex_t bindex,
+ unsigned int flags)
+{
+ struct dentry *opq_dentry, *h_dentry;
+ struct inode *h_dir;
+ int err, dlgt;
+ struct super_block *sb;
+ struct au_ndx ndx = {
+ .flags = 0,
+ .nd = NULL,
+ /* .br = NULL */
+ };
+
+ LKTRTrace("%.*s, bindex %d, flags 0x%x\n",
+ AuDLNPair(dentry), bindex, flags);
+ h_dentry = au_h_dptr(dentry, bindex);
+ AuDebugOn(!h_dentry);
+ h_dir = h_dentry->d_inode;
+ AuDebugOn(!h_dir || !S_ISDIR(h_dir->i_mode));
+
+ /* already checked by au_test_h_perm(). */
+ sb = dentry->d_sb;
+ ndx.nfsmnt = au_nfsmnt(sb, bindex);
+ dlgt = 0;
+ if (unlikely(au_ftest_diropq(flags, DLGT))) {
+ dlgt = 1;
+ au_fset_ndx(ndx.flags, DLGT);
+ }
+ opq_dentry = au_lkup_one(diropq_name.name, h_dentry, diropq_name.len,
+ &ndx);
+ if (IS_ERR(opq_dentry))
+ goto out;
+
+ if (au_ftest_diropq(flags, CREATE)) {
+ AuDebugOn(opq_dentry->d_inode);
+ err = link_or_create_wh(opq_dentry, sb, bindex,
+ dentry->d_inode);
+ if (!err) {
+ au_set_dbdiropq(dentry, bindex);
+ goto out; /* success */
+ }
+ } else {
+ AuDebugOn(/* !S_ISDIR(dentry->d_inode->i_mode)
+ * || */!opq_dentry->d_inode);
+ err = do_unlink_wh(h_dir, opq_dentry, dentry->d_inode, dlgt);
+ if (!err)
+ au_set_dbdiropq(dentry, -1);
+ }
+ dput(opq_dentry);
+ opq_dentry = ERR_PTR(err);
+
+ out:
+ AuTraceErrPtr(opq_dentry);
+ return opq_dentry;
+}
+
+struct do_diropq_args {
+ struct dentry **errp;
+ struct dentry *dentry;
+ aufs_bindex_t bindex;
+ unsigned int flags;
+};
+
+static void call_do_diropq(void *args)
+{
+ struct do_diropq_args *a = args;
+ *a->errp = do_diropq(a->dentry, a->bindex, a->flags);
+}
+
+struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
+ unsigned int flags)
+{
+ struct dentry *diropq, *h_dentry;
+
+ LKTRTrace("%.*s, bindex %d, flags 0x%x\n",
+ AuDLNPair(dentry), bindex, flags);
+
+ h_dentry = au_h_dptr(dentry, bindex);
+ if (!au_test_h_perm_sio(h_dentry->d_inode, MAY_EXEC | MAY_WRITE,
+ au_ftest_diropq(flags, DLGT)))
+ diropq = do_diropq(dentry, bindex, flags);
+ else {
+ int wkq_err;
+ struct do_diropq_args args = {
+ .errp = &diropq,
+ .dentry = dentry,
+ .bindex = bindex,
+ .flags = flags
+ };
+ wkq_err = au_wkq_wait(call_do_diropq, &args, /*dlgt*/0);
+ if (unlikely(wkq_err))
+ diropq = ERR_PTR(wkq_err);
+ }
+
+ AuTraceErrPtr(diropq);
+ return diropq;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * lookup whiteout dentry.
+ * @h_parent: hidden parent dentry which must exist and be locked
+ * @base_name: name of dentry which will be whiteouted
+ * returns dentry for whiteout.
+ */
+struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
+ struct au_ndx *ndx)
+{
+ int err;
+ struct qstr wh_name;
+ struct dentry *wh_dentry;
+
+ LKTRTrace("%.*s/%.*s\n", AuDLNPair(h_parent), AuLNPair(base_name));
+
+ err = au_wh_name_alloc(base_name->name, base_name->len, &wh_name);
+ wh_dentry = ERR_PTR(err);
+ if (!err) {
+ /* do not superio. */
+ wh_dentry = au_lkup_one(wh_name.name, h_parent,
+ wh_name.len, ndx);
+ au_wh_name_free(&wh_name);
+ }
+ AuTraceErrPtr(wh_dentry);
+ return wh_dentry;
+}
+
+/*
+ * link/create a whiteout for @dentry on @bindex.
+ */
+struct dentry *au_wh_create(struct inode *dir, struct dentry *dentry,
+ aufs_bindex_t bindex, struct dentry *h_parent,
+ struct au_ndx *ndx)
+{
+ struct dentry *wh_dentry;
+ int err;
+ struct super_block *sb;
+
+ LKTRTrace("%.*s/%.*s on b%d\n", AuDLNPair(h_parent),
+ AuDLNPair(dentry), bindex);
+
+ sb = dentry->d_sb;
+ wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, ndx);
+ if (!IS_ERR(wh_dentry) && !wh_dentry->d_inode) {
+ err = link_or_create_wh(wh_dentry, sb, bindex, dir);
+ if (!err)
+ au_set_dbwh(dentry, bindex);
+ else {
+ dput(wh_dentry);
+ wh_dentry = ERR_PTR(err);
+ }
+ }
+
+ AuTraceErrPtr(wh_dentry);
+ return wh_dentry;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* Delete all whiteouts in this directory on branch bindex. */
+static int del_wh_children(struct au_nhash *whlist, struct dentry *h_parent,
+ aufs_bindex_t bindex, struct inode *inode,
+ struct au_ndx *ndx)
+{
+ int err, i;
+ struct qstr wh_name;
+ char *p;
+ struct inode *h_dir;
+ struct hlist_head *head;
+ struct au_vdir_wh *tpos;
+ struct hlist_node *pos;
+ struct au_vdir_destr *str;
+
+ LKTRTrace("%.*s\n", AuDLNPair(h_parent));
+ h_dir = h_parent->d_inode;
+ AuDebugOn(IS_RDONLY(h_dir));
+
+ err = -ENOMEM;
+ p = __getname();
+ wh_name.name = p;
+ if (unlikely(!wh_name.name))
+ goto out;
+ memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
+ p += AUFS_WH_PFX_LEN;
+
+ /* already checked by au_test_h_perm(). */
+ err = 0;
+ for (i = 0; !err && i < AuSize_NHASH; i++) {
+ head = whlist->heads + i;
+ hlist_for_each_entry(tpos, pos, head, wh_hash) {
+ if (tpos->wh_bindex != bindex)
+ continue;
+ str = &tpos->wh_str;
+ if (str->len + AUFS_WH_PFX_LEN <= PATH_MAX) {
+ memcpy(p, str->name, str->len);
+ wh_name.len = AUFS_WH_PFX_LEN + str->len;
+ err = unlink_wh_name(h_parent, &wh_name, inode,
+ ndx);
+ if (!err)
+ continue;
+ break;
+ }
+ AuIOErr("whiteout name too long %.*s\n",
+ str->len, str->name);
+ err = -EIO;
+ break;
+ }
+ }
+ __putname(wh_name.name);
+
+ out:
+ AuTraceErr(err);
+ return err;
+}
+
+struct del_wh_children_args {
+ int *errp;
+ struct au_nhash *whlist;
+ struct dentry *h_parent;
+ aufs_bindex_t bindex;
+ struct inode *inode;
+ struct au_ndx *ndx;
+};
+
+static void call_del_wh_children(void *args)
+{
+ struct del_wh_children_args *a = args;
+ *a->errp = del_wh_children(a->whlist, a->h_parent, a->bindex,
+ a->inode, a->ndx);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * rmdir the whiteouted temporary named dir @h_dentry.
+ * @whlist: whiteouted children.
+ */
+int au_whtmp_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
+ aufs_bindex_t bindex, struct inode *dir, struct inode *inode,
+ int noself)
+{
+ int err, dlgt;
+ struct inode *h_inode, *h_dir;
+ struct super_block *sb;
+ unsigned int mnt_flags;
+ struct au_hin_ignore ign;
+ struct vfsub_args vargs;
+ struct au_ndx ndx = {
+ .flags = 0,
+ .nd = NULL,
+ /* .br = NULL */
+ };
+
+ LKTRTrace("hd %.*s, b%d, i%lu\n",
+ AuDLNPair(h_dentry), bindex, dir->i_ino);
+ IMustLock(dir);
+ IiMustAnyLock(dir);
+ h_dir = h_dentry->d_parent->d_inode; /* dir inode is locked */
+ IMustLock(h_dir);
+
+ sb = inode->i_sb;
+ mnt_flags = au_mntflags(sb);
+ dlgt = !!au_opt_test_dlgt(mnt_flags);
+ if (unlikely(dlgt))
+ au_fset_ndx(ndx.flags, DLGT);
+ ndx.nfsmnt = au_nfsmnt(sb, bindex);
+ h_inode = h_dentry->d_inode;
+ AuDebugOn(h_inode != au_h_iptr(inode, bindex));
+ au_hdir2_lock(h_inode, inode, bindex);
+
+ /*
+ * someone else might change some whiteouts while we were sleeping.
+ * it means this whlist may have an obsoleted entry.
+ */
+ if (!au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_WRITE, dlgt))
+ err = del_wh_children(whlist, h_dentry, bindex, inode, &ndx);
+ else {
+ int wkq_err;
+ /* ugly */
+ unsigned int flags = ndx.flags;
+ struct del_wh_children_args args = {
+ .errp = &err,
+ .whlist = whlist,
+ .h_parent = h_dentry,
+ .bindex = bindex,
+ .inode = inode,
+ .ndx = &ndx
+ };
+
+ ndx.flags = 0;
+ wkq_err = au_wkq_wait(call_del_wh_children, &args, /*dlgt*/0);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+ ndx.flags = flags;
+ }
+ au_hdir_unlock(h_inode, inode, bindex);
+
+ if (!err) {
+ vfsub_args_init(&vargs, &ign, dlgt, 0);
+ if (unlikely(au_opt_test(mnt_flags, UDBA_INOTIFY) && !noself))
+ vfsub_ign_hinode(&vargs, IN_DELETE_SELF,
+ au_hi(inode, bindex));
+ err = vfsub_rmdir(h_dir, h_dentry, &vargs);
+ /* d_drop(h_dentry); */
+ }
+
+ if (!err) {
+ if (au_ibstart(dir) == bindex) {
+ au_cpup_attr_timesizes(dir);
+ /* au_cpup_attr_nlink(dir); */
+ drop_nlink(dir);
+ }
+ return 0; /* success */
+ }
+
+ AuWarn("failed removing %.*s(%d), ignored\n", AuDLNPair(h_dentry), err);
+ return err;
+}
+
+static void au_whtmp_rmdir_free_args(struct au_whtmp_rmdir_args *args)
+{
+ dput(args->h_dentry);
+ au_nhash_fin(&args->whlist);
+ iput(args->inode);
+ mutex_unlock(&args->dir->i_mutex);
+ iput(args->dir);
+ kfree(args);
+}
+
+static void do_rmdir_whtmp(void *args)
+{
+ int err;
+ struct au_whtmp_rmdir_args *a = args;
+ struct super_block *sb;
+
+ LKTRTrace("%.*s, b%d, dir i%lu\n",
+ AuDLNPair(a->h_dentry), a->bindex, a->dir->i_ino);
+
+ mutex_lock(&a->dir->i_mutex);
+ sb = a->dir->i_sb;
+ si_noflush_read_lock(sb);
+ err = au_test_ro(sb, a->bindex, NULL);
+ if (!err) {
+ struct dentry *h_parent = dget_parent(a->h_dentry);
+ struct inode *h_dir = h_parent->d_inode;
+
+ ii_write_lock_child(a->inode);
+ ii_write_lock_parent(a->dir);
+ au_hdir_lock(h_dir, a->dir, a->bindex);
+ /* todo: revalidate h_dentry? */
+ err = au_whtmp_rmdir(a->h_dentry, &a->whlist, a->bindex,
+ a->dir, a->inode, a->noself);
+ au_hdir_unlock(h_dir, a->dir, a->bindex);
+ ii_write_unlock(a->dir);
+ ii_write_unlock(a->inode);
+ dput(h_parent);
+ }
+ si_read_unlock(sb);
+ au_whtmp_rmdir_free_args(a);
+ if (unlikely(err))
+ AuIOErr("err %d\n", err);
+}
+
+void au_whtmp_kick_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
+ aufs_bindex_t bindex, struct inode *dir,
+ struct inode *inode, int noself,
+ struct au_whtmp_rmdir_args *args)
+{
+ int wkq_err;
+
+ LKTRTrace("%.*s\n", AuDLNPair(h_dentry));
+ IMustLock(dir);
+
+ /* all post-process will be done in do_rmdir_whtmp(). */
+ args->h_dentry = dget(h_dentry);
+ au_nhash_init(&args->whlist);
+ au_nhash_move(&args->whlist, whlist);
+ args->bindex = bindex;
+ args->dir = igrab(dir);
+ args->inode = igrab(inode);
+ args->noself = noself;
+ wkq_err = au_wkq_nowait(do_rmdir_whtmp, args, dir->i_sb, /*dlgt*/0);
+ if (unlikely(wkq_err)) {
+ AuWarn("rmdir error %.*s (%d), ignored\n",
+ AuDLNPair(h_dentry), wkq_err);
+ au_whtmp_rmdir_free_args(args);
+ }
+}
diff --git a/fs/aufs/whout.h b/fs/aufs/whout.h
new file mode 100644
index 0000000..45333cb
--- /dev/null
+++ b/fs/aufs/whout.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * whiteout for logical deletion and opaque directory
+ */
+
+#ifndef __AUFS_WHOUT_H__
+#define __AUFS_WHOUT_H__
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h>
+#include <linux/aufs_type.h>
+#include "dir.h"
+#include "opts.h"
+#include "super.h"
+
+int au_wh_name_alloc(const char *name, int len, struct qstr *wh);
+void au_wh_name_free(struct qstr *wh);
+
+struct au_ndx;
+int au_wh_test(struct dentry *h_parent, struct qstr *wh_name, int try_sio,
+ struct au_ndx *ndx);
+int au_diropq_test(struct dentry *h_dentry, struct au_ndx *ndx);
+
+struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct qstr *prefix,
+ struct au_ndx *ndx);
+int au_whtmp_ren(struct inode *dir, struct dentry *dentry, aufs_bindex_t bindex,
+ int noself);
+int au_wh_unlink_dentry(struct inode *h_dir, struct dentry *wh_dentry,
+ struct dentry *dentry, struct inode *dir, int dlgt);
+
+struct au_branch;
+int au_wh_init(struct dentry *h_parent, struct au_branch *br,
+ struct vfsmount *nfsmnt, struct super_block *sb);
+
+/* diropq flags */
+#define AuDiropq_CREATE 1
+#define AuDiropq_DLGT (1 << 1)
+#define au_ftest_diropq(flags, name) ((flags) & AuDiropq_##name)
+#define au_fset_diropq(flags, name) { (flags) |= AuDiropq_##name; }
+#define au_fclr_diropq(flags, name) { (flags) &= ~AuDiropq_##name; }
+#ifndef CONFIG_AUFS_DLGT
+#undef AuDiropq_DLGT
+#define AuDiropq_DLGT 0
+#endif
+
+struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
+ unsigned int flags);
+
+struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
+ struct au_ndx *ndx);
+struct dentry *au_wh_create(struct inode *dir, struct dentry *dentry,
+ aufs_bindex_t bindex, struct dentry *h_parent,
+ struct au_ndx *ndx);
+
+/* real rmdir the whiteout-ed dir */
+struct au_whtmp_rmdir_args {
+ struct dentry *h_dentry;
+ struct au_nhash whlist;
+ aufs_bindex_t bindex;
+ struct inode *dir, *inode;
+ int noself;
+};
+
+struct au_nhash;
+int au_whtmp_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
+ aufs_bindex_t bindex, struct inode *dir, struct inode *inode,
+ int noself);
+void au_whtmp_kick_rmdir(struct dentry *h_dentry, struct au_nhash *whlist,
+ aufs_bindex_t bindex, struct inode *dir,
+ struct inode *inode, int noself,
+ struct au_whtmp_rmdir_args *args);
+
+/* ---------------------------------------------------------------------- */
+
+static inline
+struct dentry *au_diropq_create(struct dentry *dentry, aufs_bindex_t bindex,
+ int dlgt)
+{
+ unsigned int flags = AuDiropq_CREATE;
+ if (unlikely(dlgt))
+ au_fset_diropq(flags, DLGT);
+ return au_diropq_sio(dentry, bindex, flags);
+}
+
+static inline
+int au_diropq_remove(struct dentry *dentry, aufs_bindex_t bindex, int dlgt)
+{
+ unsigned int flags = !AuDiropq_CREATE;
+ if (unlikely(dlgt))
+ au_fset_diropq(flags, DLGT);
+ return PTR_ERR(au_diropq_sio(dentry, bindex, flags));
+}
+
+/* ---------------------------------------------------------------------- */
+
+#ifdef CONFIG_AUFS_ROBR
+/* robr.c */
+int au_test_robr_wh(struct qstr *name, struct dentry *h_parent,
+ struct qstr *wh_name, int try_sio, struct au_ndx *ndx);
+int au_test_robr_shwh(struct super_block *sb, const struct qstr *name);
+#else
+static inline
+int au_test_robr_wh(struct qstr *name, struct dentry *h_parent,
+ struct qstr *wh_name, int try_sio, struct au_ndx *ndx)
+{
+ return au_wh_test(h_parent, wh_name, try_sio, ndx);
+}
+
+static inline
+int au_test_robr_shwh(struct super_block *sb, const struct qstr *name)
+{
+ if (unlikely(!au_opt_test(au_mntflags(sb), SHWH)
+ && !strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)))
+ return -EPERM;
+ return 0;
+}
+#endif /* CONFIG_AUFS_ROBR */
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_WHOUT_H__ */
--
1.5.5.1.308.g1fbb5.dirty
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists