--- /dev/null
+/*
+ * Copyright (C) 2005-2011 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * inode operations (add entry)
+ */
+
+#include "aufs.h"
+
+/*
+ * final procedure of adding a new entry, except link(2).
+ * remove whiteout, instantiate, copyup the parent dir's times and size
+ * and update version.
+ * if it failed, re-create the removed whiteout.
+ */
+static int epilog(struct inode *dir, aufs_bindex_t bindex,
+ struct dentry *wh_dentry, struct dentry *dentry)
+{
+ int err, rerr;
+ aufs_bindex_t bwh;
+ struct path h_path;
+ struct inode *inode, *h_dir;
+ struct dentry *wh;
+
+ bwh = -1;
+ if (wh_dentry) {
+ h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
+ IMustLock(h_dir);
+ AuDebugOn(au_h_iptr(dir, bindex) != h_dir);
+ bwh = au_dbwh(dentry);
+ h_path.dentry = wh_dentry;
+ h_path.mnt = au_sbr_mnt(dir->i_sb, bindex);
+ err = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path,
+ dentry);
+ if (unlikely(err))
+ goto out;
+ }
+
+ inode = au_new_inode(dentry, /*must_new*/1);
+ if (!IS_ERR(inode)) {
+ d_instantiate(dentry, inode);
+ dir = dentry->d_parent->d_inode; /* dir inode is locked */
+ IMustLock(dir);
+ if (au_ibstart(dir) == au_dbstart(dentry))
+ au_cpup_attr_timesizes(dir);
+ dir->i_version++;
+ return 0; /* success */
+ }
+
+ err = PTR_ERR(inode);
+ if (!wh_dentry)
+ goto out;
+
+ /* revert */
+ /* dir inode is locked */
+ wh = au_wh_create(dentry, bwh, wh_dentry->d_parent);
+ rerr = PTR_ERR(wh);
+ if (IS_ERR(wh)) {
+ AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
+ AuDLNPair(dentry), err, rerr);
+ err = -EIO;
+ } else
+ dput(wh);
+
+out:
+ return err;
+}
+
+static int au_d_may_add(struct dentry *dentry)
+{
+ int err;
+
+ err = 0;
+ if (unlikely(d_unhashed(dentry)))
+ err = -ENOENT;
+ if (unlikely(dentry->d_inode))
+ err = -EEXIST;
+ return err;
+}
+
+/*
+ * simple tests for the adding inode operations.
+ * following the checks in vfs, plus the parent-child relationship.
+ */
+int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
+ struct dentry *h_parent, int isdir)
+{
+ int err;
+ umode_t h_mode;
+ struct dentry *h_dentry;
+ struct inode *h_inode;
+
+ err = -ENAMETOOLONG;
+ if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
+ goto out;
+
+ h_dentry = au_h_dptr(dentry, bindex);
+ h_inode = h_dentry->d_inode;
+ if (!dentry->d_inode) {
+ err = -EEXIST;
+ if (unlikely(h_inode))
+ goto out;
+ } else {
+ /* rename(2) case */
+ err = -EIO;
+ if (unlikely(!h_inode || !h_inode->i_nlink))
+ goto out;
+
+ h_mode = h_inode->i_mode;
+ if (!isdir) {
+ err = -EISDIR;
+ if (unlikely(S_ISDIR(h_mode)))
+ goto out;
+ } else if (unlikely(!S_ISDIR(h_mode))) {
+ err = -ENOTDIR;
+ goto out;
+ }
+ }
+
+ err = 0;
+ /* expected parent dir is locked */
+ if (unlikely(h_parent != h_dentry->d_parent))
+ err = -EIO;
+
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+/*
+ * initial procedure of adding a new entry.
+ * prepare writable branch and the parent dir, lock it,
+ * and lookup whiteout for the new entry.
+ */
+static struct dentry*
+lock_hdir_lkup_wh(struct dentry *dentry, struct au_dtime *dt,
+ struct dentry *src_dentry, struct au_pin *pin,
+ struct au_wr_dir_args *wr_dir_args)
+{
+ struct dentry *wh_dentry, *h_parent;
+ struct super_block *sb;
+ struct au_branch *br;
+ int err;
+ unsigned int udba;
+ aufs_bindex_t bcpup;
+
+ AuDbg("%.*s\n", AuDLNPair(dentry));
+
+ err = au_wr_dir(dentry, src_dentry, wr_dir_args);
+ bcpup = err;
+ wh_dentry = ERR_PTR(err);
+ if (unlikely(err < 0))
+ goto out;
+
+ sb = dentry->d_sb;
+ udba = au_opt_udba(sb);
+ err = au_pin(pin, dentry, bcpup, udba,
+ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
+ wh_dentry = ERR_PTR(err);
+ if (unlikely(err))
+ goto out;
+
+ h_parent = au_pinned_h_parent(pin);
+ if (udba != AuOpt_UDBA_NONE
+ && au_dbstart(dentry) == bcpup)
+ err = au_may_add(dentry, bcpup, h_parent,
+ au_ftest_wrdir(wr_dir_args->flags, ISDIR));
+ else if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
+ err = -ENAMETOOLONG;
+ wh_dentry = ERR_PTR(err);
+ if (unlikely(err))
+ goto out_unpin;
+
+ br = au_sbr(sb, bcpup);
+ if (dt) {
+ struct path tmp = {
+ .dentry = h_parent,
+ .mnt = br->br_mnt
+ };
+ au_dtime_store(dt, au_pinned_parent(pin), &tmp);
+ }
+
+ wh_dentry = NULL;
+ if (bcpup != au_dbwh(dentry))
+ goto out; /* success */
+
+ wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
+
+out_unpin:
+ if (IS_ERR(wh_dentry))
+ au_unpin(pin);
+out:
+ return wh_dentry;
+}
+
+/* ---------------------------------------------------------------------- */
+
+enum { Mknod, Symlink, Creat };
+struct simple_arg {
+ int type;
+ union {
+ struct {
+ int mode;
+ struct nameidata *nd;
+ } c;
+ struct {
+ const char *symname;
+ } s;
+ struct {
+ int mode;
+ dev_t dev;
+ } m;
+ } u;
+};
+
+static int add_simple(struct inode *dir, struct dentry *dentry,
+ struct simple_arg *arg)
+{
+ int err;
+ aufs_bindex_t bstart;
+ unsigned char created;
+ struct au_dtime dt;
+ struct au_pin pin;
+ struct path h_path;
+ struct dentry *wh_dentry, *parent;
+ struct inode *h_dir;
+ struct au_wr_dir_args wr_dir_args = {
+ .force_btgt = -1,
+ .flags = AuWrDir_ADD_ENTRY
+ };
+
+ AuDbg("%.*s\n", AuDLNPair(dentry));
+ IMustLock(dir);
+
+ parent = dentry->d_parent; /* dir inode is locked */
+ err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
+ if (unlikely(err))
+ goto out;
+ err = au_d_may_add(dentry);
+ if (unlikely(err))
+ goto out_unlock;
+ di_write_lock_parent(parent);
+ wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL, &pin,
+ &wr_dir_args);
+ err = PTR_ERR(wh_dentry);
+ if (IS_ERR(wh_dentry))
+ goto out_parent;
+
+ bstart = au_dbstart(dentry);
+ h_path.dentry = au_h_dptr(dentry, bstart);
+ h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
+ h_dir = au_pinned_h_dir(&pin);
+ switch (arg->type) {
+ case Creat:
+ err = vfsub_create(h_dir, &h_path, arg->u.c.mode);
+ break;
+ case Symlink:
+ err = vfsub_symlink(h_dir, &h_path, arg->u.s.symname);
+ break;
+ case Mknod:
+ err = vfsub_mknod(h_dir, &h_path, arg->u.m.mode, arg->u.m.dev);
+ break;
+ default:
+ BUG();
+ }
+ created = !err;
+ if (!err)
+ err = epilog(dir, bstart, wh_dentry, dentry);
+
+ /* revert */
+ if (unlikely(created && err && h_path.dentry->d_inode)) {
+ int rerr;
+ rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
+ if (rerr) {
+ AuIOErr("%.*s revert failure(%d, %d)\n",
+ AuDLNPair(dentry), err, rerr);
+ err = -EIO;
+ }
+ au_dtime_revert(&dt);
+ }
+
+ au_unpin(&pin);
+ dput(wh_dentry);
+
+out_parent:
+ di_write_unlock(parent);
+out_unlock:
+ if (unlikely(err)) {
+ au_update_dbstart(dentry);
+ d_drop(dentry);
+ }
+ aufs_read_unlock(dentry, AuLock_DW);
+out:
+ return err;
+}
+
+int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
+{
+ struct simple_arg arg = {
+ .type = Mknod,
+ .u.m = {
+ .mode = mode,
+ .dev = dev
+ }
+ };
+ return add_simple(dir, dentry, &arg);
+}
+
+int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ struct simple_arg arg = {
+ .type = Symlink,
+ .u.s.symname = symname
+ };
+ return add_simple(dir, dentry, &arg);
+}
+
+int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ struct simple_arg arg = {
+ .type = Creat,
+ .u.c = {
+ .mode = mode,
+ .nd = nd
+ }
+ };
+ return add_simple(dir, dentry, &arg);
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct au_link_args {
+ aufs_bindex_t bdst, bsrc;
+ struct au_pin pin;
+ struct path h_path;
+ struct dentry *src_parent, *parent;
+};
+
+static int au_cpup_before_link(struct dentry *src_dentry,
+ struct au_link_args *a)
+{
+ int err;
+ struct dentry *h_src_dentry;
+ struct mutex *h_mtx;
+ struct file *h_file;
+
+ di_read_lock_parent(a->src_parent, AuLock_IR);
+ err = au_test_and_cpup_dirs(src_dentry, a->bdst);
+ if (unlikely(err))
+ goto out;
+
+ h_src_dentry = au_h_dptr(src_dentry, a->bsrc);
+ h_mtx = &h_src_dentry->d_inode->i_mutex;
+ err = au_pin(&a->pin, src_dentry, a->bdst,
+ au_opt_udba(src_dentry->d_sb),
+ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
+ if (unlikely(err))
+ goto out;
+ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
+ h_file = au_h_open_pre(src_dentry, a->bsrc);
+ if (IS_ERR(h_file)) {
+ err = PTR_ERR(h_file);
+ h_file = NULL;
+ } else
+ err = au_sio_cpup_simple(src_dentry, a->bdst, a->bsrc,
+ AuCpup_DTIME /* | AuCpup_KEEPLINO */);
+ mutex_unlock(h_mtx);
+ au_h_open_post(src_dentry, a->bsrc, h_file);
+ au_unpin(&a->pin);
+
+out:
+ di_read_unlock(a->src_parent, AuLock_IR);
+ return err;
+}
+
+static int au_cpup_or_link(struct dentry *src_dentry, struct au_link_args *a)
+{
+ int err;
+ unsigned char plink;
+ struct inode *h_inode, *inode;
+ struct dentry *h_src_dentry;
+ struct super_block *sb;
+ struct file *h_file;
+
+ plink = 0;
+ h_inode = NULL;
+ sb = src_dentry->d_sb;
+ inode = src_dentry->d_inode;
+ if (au_ibstart(inode) <= a->bdst)
+ h_inode = au_h_iptr(inode, a->bdst);
+ if (!h_inode || !h_inode->i_nlink) {
+ /* copyup src_dentry as the name of dentry. */
+ au_set_dbstart(src_dentry, a->bdst);
+ au_set_h_dptr(src_dentry, a->bdst, dget(a->h_path.dentry));
+ h_inode = au_h_dptr(src_dentry, a->bsrc)->d_inode;
+ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
+ h_file = au_h_open_pre(src_dentry, a->bsrc);
+ if (IS_ERR(h_file)) {
+ err = PTR_ERR(h_file);
+ h_file = NULL;
+ } else
+ err = au_sio_cpup_single(src_dentry, a->bdst, a->bsrc,
+ -1, AuCpup_KEEPLINO,
+ a->parent);
+ mutex_unlock(&h_inode->i_mutex);
+ au_h_open_post(src_dentry, a->bsrc, h_file);
+ au_set_h_dptr(src_dentry, a->bdst, NULL);
+ au_set_dbstart(src_dentry, a->bsrc);
+ } else {
+ /* the inode of src_dentry already exists on a.bdst branch */
+ h_src_dentry = d_find_alias(h_inode);
+ if (!h_src_dentry && au_plink_test(inode)) {
+ plink = 1;
+ h_src_dentry = au_plink_lkup(inode, a->bdst);
+ err = PTR_ERR(h_src_dentry);
+ if (IS_ERR(h_src_dentry))
+ goto out;
+
+ if (unlikely(!h_src_dentry->d_inode)) {
+ dput(h_src_dentry);
+ h_src_dentry = NULL;
+ }
+
+ }
+ if (h_src_dentry) {
+ err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
+ &a->h_path);
+ dput(h_src_dentry);
+ } else {
+ AuIOErr("no dentry found for hi%lu on b%d\n",
+ h_inode->i_ino, a->bdst);
+ err = -EIO;
+ }
+ }
+
+ if (!err && !plink)
+ au_plink_append(inode, a->bdst, a->h_path.dentry);
+
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+int aufs_link(struct dentry *src_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ int err, rerr;
+ struct au_dtime dt;
+ struct au_link_args *a;
+ struct dentry *wh_dentry, *h_src_dentry;
+ struct inode *inode;
+ struct super_block *sb;
+ struct au_wr_dir_args wr_dir_args = {
+ /* .force_btgt = -1, */
+ .flags = AuWrDir_ADD_ENTRY
+ };
+
+ IMustLock(dir);
+ inode = src_dentry->d_inode;
+ IMustLock(inode);
+
+ err = -ENOMEM;
+ a = kzalloc(sizeof(*a), GFP_NOFS);
+ if (unlikely(!a))
+ goto out;
+
+ a->parent = dentry->d_parent; /* dir inode is locked */
+ err = aufs_read_and_write_lock2(dentry, src_dentry,
+ AuLock_NOPLM | AuLock_GEN);
+ if (unlikely(err))
+ goto out_kfree;
+ err = au_d_hashed_positive(src_dentry);
+ if (unlikely(err))
+ goto out_unlock;
+ err = au_d_may_add(dentry);
+ if (unlikely(err))
+ goto out_unlock;
+
+ a->src_parent = dget_parent(src_dentry);
+ wr_dir_args.force_btgt = au_ibstart(inode);
+
+ di_write_lock_parent(a->parent);
+ wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
+ wh_dentry = lock_hdir_lkup_wh(dentry, &dt, src_dentry, &a->pin,
+ &wr_dir_args);
+ err = PTR_ERR(wh_dentry);
+ if (IS_ERR(wh_dentry))
+ goto out_parent;
+
+ err = 0;
+ sb = dentry->d_sb;
+ a->bdst = au_dbstart(dentry);
+ a->h_path.dentry = au_h_dptr(dentry, a->bdst);
+ a->h_path.mnt = au_sbr_mnt(sb, a->bdst);
+ a->bsrc = au_ibstart(inode);
+ h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
+ if (!h_src_dentry) {
+ a->bsrc = au_dbstart(src_dentry);
+ h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
+ AuDebugOn(!h_src_dentry);
+ } else if (IS_ERR(h_src_dentry))
+ goto out_parent;
+
+ if (au_opt_test(au_mntflags(sb), PLINK)) {
+ if (a->bdst < a->bsrc
+ /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */)
+ err = au_cpup_or_link(src_dentry, a);
+ else
+ err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
+ &a->h_path);
+ dput(h_src_dentry);
+ } else {
+ /*
+ * copyup src_dentry to the branch we process,
+ * and then link(2) to it.
+ */
+ dput(h_src_dentry);
+ if (a->bdst < a->bsrc
+ /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */) {
+ au_unpin(&a->pin);
+ di_write_unlock(a->parent);
+ err = au_cpup_before_link(src_dentry, a);
+ di_write_lock_parent(a->parent);
+ if (!err)
+ err = au_pin(&a->pin, dentry, a->bdst,
+ au_opt_udba(sb),
+ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
+ if (unlikely(err))
+ goto out_wh;
+ }
+ if (!err) {
+ h_src_dentry = au_h_dptr(src_dentry, a->bdst);
+ err = -ENOENT;
+ if (h_src_dentry && h_src_dentry->d_inode)
+ err = vfsub_link(h_src_dentry,
+ au_pinned_h_dir(&a->pin),
+ &a->h_path);
+ }
+ }
+ if (unlikely(err))
+ goto out_unpin;
+
+ if (wh_dentry) {
+ a->h_path.dentry = wh_dentry;
+ err = au_wh_unlink_dentry(au_pinned_h_dir(&a->pin), &a->h_path,
+ dentry);
+ if (unlikely(err))
+ goto out_revert;
+ }
+
+ dir->i_version++;
+ if (au_ibstart(dir) == au_dbstart(dentry))
+ au_cpup_attr_timesizes(dir);
+ inc_nlink(inode);
+ inode->i_ctime = dir->i_ctime;
+ d_instantiate(dentry, au_igrab(inode));
+ if (d_unhashed(a->h_path.dentry))
+ /* some filesystem calls d_drop() */
+ d_drop(dentry);
+ goto out_unpin; /* success */
+
+out_revert:
+ rerr = vfsub_unlink(au_pinned_h_dir(&a->pin), &a->h_path, /*force*/0);
+ if (unlikely(rerr)) {
+ AuIOErr("%.*s reverting failed(%d, %d)\n",
+ AuDLNPair(dentry), err, rerr);
+ err = -EIO;
+ }
+ au_dtime_revert(&dt);
+out_unpin:
+ au_unpin(&a->pin);
+out_wh:
+ dput(wh_dentry);
+out_parent:
+ di_write_unlock(a->parent);
+ dput(a->src_parent);
+out_unlock:
+ if (unlikely(err)) {
+ au_update_dbstart(dentry);
+ d_drop(dentry);
+ }
+ aufs_read_and_write_unlock2(dentry, src_dentry);
+out_kfree:
+ kfree(a);
+out:
+ return err;
+}
+
+int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ int err, rerr;
+ aufs_bindex_t bindex;
+ unsigned char diropq;
+ struct path h_path;
+ struct dentry *wh_dentry, *parent, *opq_dentry;
+ struct mutex *h_mtx;
+ struct super_block *sb;
+ struct {
+ struct au_pin pin;
+ struct au_dtime dt;
+ } *a; /* reduce the stack usage */
+ struct au_wr_dir_args wr_dir_args = {
+ .force_btgt = -1,
+ .flags = AuWrDir_ADD_ENTRY | AuWrDir_ISDIR
+ };
+
+ IMustLock(dir);
+
+ err = -ENOMEM;
+ a = kmalloc(sizeof(*a), GFP_NOFS);
+ if (unlikely(!a))
+ goto out;
+
+ err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
+ if (unlikely(err))
+ goto out_free;
+ err = au_d_may_add(dentry);
+ if (unlikely(err))
+ goto out_unlock;
+
+ parent = dentry->d_parent; /* dir inode is locked */
+ di_write_lock_parent(parent);
+ wh_dentry = lock_hdir_lkup_wh(dentry, &a->dt, /*src_dentry*/NULL,
+ &a->pin, &wr_dir_args);
+ err = PTR_ERR(wh_dentry);
+ if (IS_ERR(wh_dentry))
+ goto out_parent;
+
+ sb = dentry->d_sb;
+ bindex = au_dbstart(dentry);
+ h_path.dentry = au_h_dptr(dentry, bindex);
+ h_path.mnt = au_sbr_mnt(sb, bindex);
+ err = vfsub_mkdir(au_pinned_h_dir(&a->pin), &h_path, mode);
+ if (unlikely(err))
+ goto out_unpin;
+
+ /* make the dir opaque */
+ diropq = 0;
+ h_mtx = &h_path.dentry->d_inode->i_mutex;
+ if (wh_dentry
+ || au_opt_test(au_mntflags(sb), ALWAYS_DIROPQ)) {
+ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
+ opq_dentry = au_diropq_create(dentry, bindex);
+ mutex_unlock(h_mtx);
+ err = PTR_ERR(opq_dentry);
+ if (IS_ERR(opq_dentry))
+ goto out_dir;
+ dput(opq_dentry);
+ diropq = 1;
+ }
+
+ err = epilog(dir, bindex, wh_dentry, dentry);
+ if (!err) {
+ inc_nlink(dir);
+ goto out_unpin; /* success */
+ }
+
+ /* revert */
+ if (diropq) {
+ AuLabel(revert opq);
+ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
+ rerr = au_diropq_remove(dentry, bindex);
+ mutex_unlock(h_mtx);
+ if (rerr) {
+ AuIOErr("%.*s reverting diropq failed(%d, %d)\n",
+ AuDLNPair(dentry), err, rerr);
+ err = -EIO;
+ }
+ }
+
+out_dir:
+ AuLabel(revert dir);
+ rerr = vfsub_rmdir(au_pinned_h_dir(&a->pin), &h_path);
+ if (rerr) {
+ AuIOErr("%.*s reverting dir failed(%d, %d)\n",
+ AuDLNPair(dentry), err, rerr);
+ err = -EIO;
+ }
+ au_dtime_revert(&a->dt);
+out_unpin:
+ au_unpin(&a->pin);
+ dput(wh_dentry);
+out_parent:
+ di_write_unlock(parent);
+out_unlock:
+ if (unlikely(err)) {
+ au_update_dbstart(dentry);
+ d_drop(dentry);
+ }
+ aufs_read_unlock(dentry, AuLock_DW);
+out_free:
+ kfree(a);
+out:
+ return err;
+}
git.openpandora.org / pandora-kernel.git / blobdiff