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-rw-r--r--fs/aufs/i_op.c1447
1 files changed, 1447 insertions, 0 deletions
diff --git a/fs/aufs/i_op.c b/fs/aufs/i_op.c
new file mode 100644
index 000000000..17364e4f1
--- /dev/null
+++ b/fs/aufs/i_op.c
@@ -0,0 +1,1447 @@
+/*
+ * 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 operations (except add/del/rename)
+ */
+
+#include <linux/device_cgroup.h>
+#include <linux/fs_stack.h>
+#include <linux/mm.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+#include "aufs.h"
+
+static int h_permission(struct inode *h_inode, int mask,
+ struct vfsmount *h_mnt, int brperm)
+{
+ int err;
+ const unsigned char write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
+
+ err = -EACCES;
+ if ((write_mask && IS_IMMUTABLE(h_inode))
+ || ((mask & MAY_EXEC)
+ && S_ISREG(h_inode->i_mode)
+ && ((h_mnt->mnt_flags & MNT_NOEXEC)
+ || !(h_inode->i_mode & S_IXUGO))))
+ goto out;
+
+ /*
+ * - skip the lower fs test in the case of write to ro branch.
+ * - nfs dir permission write check is optimized, but a policy for
+ * link/rename requires a real check.
+ * - nfs always sets MS_POSIXACL regardless its mount option 'noacl.'
+ * in this case, generic_permission() returns -EOPNOTSUPP.
+ */
+ if ((write_mask && !au_br_writable(brperm))
+ || (au_test_nfs(h_inode->i_sb) && S_ISDIR(h_inode->i_mode)
+ && write_mask && !(mask & MAY_READ))
+ || !h_inode->i_op->permission) {
+ /* AuLabel(generic_permission); */
+ /* AuDbg("get_acl %pf\n", h_inode->i_op->get_acl); */
+ err = generic_permission(h_inode, mask);
+ if (err == -EOPNOTSUPP && au_test_nfs_noacl(h_inode))
+ err = h_inode->i_op->permission(h_inode, mask);
+ AuTraceErr(err);
+ } else {
+ /* AuLabel(h_inode->permission); */
+ err = h_inode->i_op->permission(h_inode, mask);
+ AuTraceErr(err);
+ }
+
+ if (!err)
+ err = devcgroup_inode_permission(h_inode, mask);
+ if (!err)
+ err = security_inode_permission(h_inode, mask);
+
+#if 0
+ if (!err) {
+ /* todo: do we need to call ima_path_check()? */
+ struct path h_path = {
+ .dentry =
+ .mnt = h_mnt
+ };
+ err = ima_path_check(&h_path,
+ mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
+ IMA_COUNT_LEAVE);
+ }
+#endif
+
+out:
+ return err;
+}
+
+static int aufs_permission(struct inode *inode, int mask)
+{
+ int err;
+ aufs_bindex_t bindex, bend;
+ const unsigned char isdir = !!S_ISDIR(inode->i_mode),
+ write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
+ struct inode *h_inode;
+ struct super_block *sb;
+ struct au_branch *br;
+
+ /* todo: support rcu-walk? */
+ if (mask & MAY_NOT_BLOCK)
+ return -ECHILD;
+
+ sb = inode->i_sb;
+ si_read_lock(sb, AuLock_FLUSH);
+ ii_read_lock_child(inode);
+#if 0
+ err = au_iigen_test(inode, au_sigen(sb));
+ if (unlikely(err))
+ goto out;
+#endif
+
+ if (!isdir
+ || write_mask
+ || au_opt_test(au_mntflags(sb), DIRPERM1)) {
+ err = au_busy_or_stale();
+ h_inode = au_h_iptr(inode, au_ibstart(inode));
+ if (unlikely(!h_inode
+ || (h_inode->i_mode & S_IFMT)
+ != (inode->i_mode & S_IFMT)))
+ goto out;
+
+ err = 0;
+ bindex = au_ibstart(inode);
+ br = au_sbr(sb, bindex);
+ err = h_permission(h_inode, mask, au_br_mnt(br), br->br_perm);
+ if (write_mask
+ && !err
+ && !special_file(h_inode->i_mode)) {
+ /* test whether the upper writable branch exists */
+ err = -EROFS;
+ for (; bindex >= 0; bindex--)
+ if (!au_br_rdonly(au_sbr(sb, bindex))) {
+ err = 0;
+ break;
+ }
+ }
+ goto out;
+ }
+
+ /* non-write to dir */
+ err = 0;
+ bend = au_ibend(inode);
+ for (bindex = au_ibstart(inode); !err && bindex <= bend; bindex++) {
+ h_inode = au_h_iptr(inode, bindex);
+ if (h_inode) {
+ err = au_busy_or_stale();
+ if (unlikely(!S_ISDIR(h_inode->i_mode)))
+ break;
+
+ br = au_sbr(sb, bindex);
+ err = h_permission(h_inode, mask, au_br_mnt(br),
+ br->br_perm);
+ }
+ }
+
+out:
+ ii_read_unlock(inode);
+ si_read_unlock(sb);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct dentry *ret, *parent;
+ struct inode *inode;
+ struct super_block *sb;
+ int err, npositive;
+
+ IMustLock(dir);
+
+ /* todo: support rcu-walk? */
+ ret = ERR_PTR(-ECHILD);
+ if (flags & LOOKUP_RCU)
+ goto out;
+
+ ret = ERR_PTR(-ENAMETOOLONG);
+ if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
+ goto out;
+
+ sb = dir->i_sb;
+ err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
+ ret = ERR_PTR(err);
+ if (unlikely(err))
+ goto out;
+
+ err = au_di_init(dentry);
+ ret = ERR_PTR(err);
+ if (unlikely(err))
+ goto out_si;
+
+ inode = NULL;
+ npositive = 0; /* suppress a warning */
+ parent = dentry->d_parent; /* dir inode is locked */
+ di_read_lock_parent(parent, AuLock_IR);
+ err = au_alive_dir(parent);
+ if (!err)
+ err = au_digen_test(parent, au_sigen(sb));
+ if (!err) {
+ npositive = au_lkup_dentry(dentry, au_dbstart(parent),
+ /*type*/0);
+ err = npositive;
+ }
+ di_read_unlock(parent, AuLock_IR);
+ ret = ERR_PTR(err);
+ if (unlikely(err < 0))
+ goto out_unlock;
+
+ if (npositive) {
+ inode = au_new_inode(dentry, /*must_new*/0);
+ if (IS_ERR(inode)) {
+ ret = (void *)inode;
+ inode = NULL;
+ goto out_unlock;
+ }
+ }
+
+ if (inode)
+ atomic_inc(&inode->i_count);
+ ret = d_splice_alias(inode, dentry);
+#if 0
+ if (unlikely(d_need_lookup(dentry))) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
+ spin_unlock(&dentry->d_lock);
+ } else
+#endif
+ if (inode) {
+ if (!IS_ERR(ret)) {
+ iput(inode);
+ if (ret && ret != dentry)
+ ii_write_unlock(inode);
+ } else {
+ ii_write_unlock(inode);
+ iput(inode);
+ inode = NULL;
+ }
+ }
+
+out_unlock:
+ di_write_unlock(dentry);
+ if (inode) {
+ /* verbose coding for lock class name */
+ if (unlikely(S_ISLNK(inode->i_mode)))
+ au_rw_class(&au_di(dentry)->di_rwsem,
+ au_lc_key + AuLcSymlink_DIINFO);
+ else if (unlikely(S_ISDIR(inode->i_mode)))
+ au_rw_class(&au_di(dentry)->di_rwsem,
+ au_lc_key + AuLcDir_DIINFO);
+ else /* likely */
+ au_rw_class(&au_di(dentry)->di_rwsem,
+ au_lc_key + AuLcNonDir_DIINFO);
+ }
+out_si:
+ si_read_unlock(sb);
+out:
+ return ret;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct aopen_node {
+ struct hlist_node hlist;
+ struct file *file, *h_file;
+};
+
+static int au_do_aopen(struct inode *inode, struct file *file)
+{
+ struct au_sphlhead *aopen;
+ struct aopen_node *node;
+ struct au_do_open_args args = {
+ .no_lock = 1,
+ .open = au_do_open_nondir
+ };
+
+ aopen = &au_sbi(inode->i_sb)->si_aopen;
+ spin_lock(&aopen->spin);
+ hlist_for_each_entry(node, &aopen->head, hlist)
+ if (node->file == file) {
+ args.h_file = node->h_file;
+ break;
+ }
+ spin_unlock(&aopen->spin);
+ /* AuDebugOn(!args.h_file); */
+
+ return au_do_open(file, &args);
+}
+
+static int aufs_atomic_open(struct inode *dir, struct dentry *dentry,
+ struct file *file, unsigned int open_flag,
+ umode_t create_mode, int *opened)
+{
+ int err, h_opened = *opened;
+ struct dentry *parent;
+ struct dentry *d;
+ struct au_sphlhead *aopen;
+ struct vfsub_aopen_args args = {
+ .open_flag = open_flag,
+ .create_mode = create_mode,
+ .opened = &h_opened
+ };
+ struct aopen_node aopen_node = {
+ .file = file
+ };
+
+ IMustLock(dir);
+ AuDbg("open_flag 0x%x\n", open_flag);
+ AuDbgDentry(dentry);
+
+ err = 0;
+ if (!au_di(dentry)) {
+ d = aufs_lookup(dir, dentry, /*flags*/0);
+ if (IS_ERR(d)) {
+ err = PTR_ERR(d);
+ goto out;
+ } else if (d) {
+ /*
+ * obsoleted dentry found.
+ * another error will be returned later.
+ */
+ d_drop(d);
+ dput(d);
+ AuDbgDentry(d);
+ }
+ AuDbgDentry(dentry);
+ }
+
+ if (d_is_positive(dentry)
+ || d_unhashed(dentry)
+ || d_unlinked(dentry)
+ || !(open_flag & O_CREAT))
+ goto out_no_open;
+
+ err = aufs_read_lock(dentry, AuLock_DW | AuLock_FLUSH | AuLock_GEN);
+ if (unlikely(err))
+ goto out;
+
+ parent = dentry->d_parent; /* dir is locked */
+ di_write_lock_parent(parent);
+ err = au_lkup_dentry(dentry, /*bstart*/0, /*type*/0);
+ if (unlikely(err))
+ goto out_unlock;
+
+ AuDbgDentry(dentry);
+ if (d_is_positive(dentry))
+ goto out_unlock;
+
+ args.file = get_empty_filp();
+ err = PTR_ERR(args.file);
+ if (IS_ERR(args.file))
+ goto out_unlock;
+
+ args.file->f_flags = file->f_flags;
+ err = au_aopen_or_create(dir, dentry, &args);
+ AuTraceErr(err);
+ AuDbgFile(args.file);
+ if (unlikely(err < 0)) {
+ if (h_opened & FILE_OPENED)
+ fput(args.file);
+ else
+ put_filp(args.file);
+ goto out_unlock;
+ }
+
+ /* some filesystems don't set FILE_CREATED while succeeded? */
+ *opened |= FILE_CREATED;
+ if (h_opened & FILE_OPENED)
+ aopen_node.h_file = args.file;
+ else {
+ put_filp(args.file);
+ args.file = NULL;
+ }
+ aopen = &au_sbi(dir->i_sb)->si_aopen;
+ au_sphl_add(&aopen_node.hlist, aopen);
+ err = finish_open(file, dentry, au_do_aopen, opened);
+ au_sphl_del(&aopen_node.hlist, aopen);
+ AuTraceErr(err);
+ AuDbgFile(file);
+ if (aopen_node.h_file)
+ fput(aopen_node.h_file);
+
+out_unlock:
+ di_write_unlock(parent);
+ aufs_read_unlock(dentry, AuLock_DW);
+ AuDbgDentry(dentry);
+ if (unlikely(err))
+ goto out;
+out_no_open:
+ if (!err && !(*opened & FILE_CREATED)) {
+ AuLabel(out_no_open);
+ dget(dentry);
+ err = finish_no_open(file, dentry);
+ }
+out:
+ AuDbg("%pd%s%s\n", dentry,
+ (*opened & FILE_CREATED) ? " created" : "",
+ (*opened & FILE_OPENED) ? " opened" : "");
+ AuTraceErr(err);
+ return err;
+}
+
+
+/* ---------------------------------------------------------------------- */
+
+static int au_wr_dir_cpup(struct dentry *dentry, struct dentry *parent,
+ const unsigned char add_entry, aufs_bindex_t bcpup,
+ aufs_bindex_t bstart)
+{
+ int err;
+ struct dentry *h_parent;
+ struct inode *h_dir;
+
+ if (add_entry)
+ IMustLock(d_inode(parent));
+ else
+ di_write_lock_parent(parent);
+
+ err = 0;
+ if (!au_h_dptr(parent, bcpup)) {
+ if (bstart > bcpup)
+ err = au_cpup_dirs(dentry, bcpup);
+ else if (bstart < bcpup)
+ err = au_cpdown_dirs(dentry, bcpup);
+ else
+ BUG();
+ }
+ if (!err && add_entry && !au_ftest_wrdir(add_entry, TMPFILE)) {
+ h_parent = au_h_dptr(parent, bcpup);
+ h_dir = d_inode(h_parent);
+ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
+ err = au_lkup_neg(dentry, bcpup, /*wh*/0);
+ /* todo: no unlock here */
+ mutex_unlock(&h_dir->i_mutex);
+
+ AuDbg("bcpup %d\n", bcpup);
+ if (!err) {
+ if (d_really_is_negative(dentry))
+ au_set_h_dptr(dentry, bstart, NULL);
+ au_update_dbrange(dentry, /*do_put_zero*/0);
+ }
+ }
+
+ if (!add_entry)
+ di_write_unlock(parent);
+ if (!err)
+ err = bcpup; /* success */
+
+ AuTraceErr(err);
+ return err;
+}
+
+/*
+ * decide the branch and the parent dir where we will create a new entry.
+ * returns new bindex or an error.
+ * copyup the parent dir if needed.
+ */
+int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
+ struct au_wr_dir_args *args)
+{
+ int err;
+ unsigned int flags;
+ aufs_bindex_t bcpup, bstart, src_bstart;
+ const unsigned char add_entry
+ = au_ftest_wrdir(args->flags, ADD_ENTRY)
+ | au_ftest_wrdir(args->flags, TMPFILE);
+ struct super_block *sb;
+ struct dentry *parent;
+ struct au_sbinfo *sbinfo;
+
+ sb = dentry->d_sb;
+ sbinfo = au_sbi(sb);
+ parent = dget_parent(dentry);
+ bstart = au_dbstart(dentry);
+ bcpup = bstart;
+ if (args->force_btgt < 0) {
+ if (src_dentry) {
+ src_bstart = au_dbstart(src_dentry);
+ if (src_bstart < bstart)
+ bcpup = src_bstart;
+ } else if (add_entry) {
+ flags = 0;
+ if (au_ftest_wrdir(args->flags, ISDIR))
+ au_fset_wbr(flags, DIR);
+ err = AuWbrCreate(sbinfo, dentry, flags);
+ bcpup = err;
+ }
+
+ if (bcpup < 0 || au_test_ro(sb, bcpup, d_inode(dentry))) {
+ if (add_entry)
+ err = AuWbrCopyup(sbinfo, dentry);
+ else {
+ if (!IS_ROOT(dentry)) {
+ di_read_lock_parent(parent, !AuLock_IR);
+ err = AuWbrCopyup(sbinfo, dentry);
+ di_read_unlock(parent, !AuLock_IR);
+ } else
+ err = AuWbrCopyup(sbinfo, dentry);
+ }
+ bcpup = err;
+ if (unlikely(err < 0))
+ goto out;
+ }
+ } else {
+ bcpup = args->force_btgt;
+ AuDebugOn(au_test_ro(sb, bcpup, d_inode(dentry)));
+ }
+
+ AuDbg("bstart %d, bcpup %d\n", bstart, bcpup);
+ err = bcpup;
+ if (bcpup == bstart)
+ goto out; /* success */
+
+ /* copyup the new parent into the branch we process */
+ err = au_wr_dir_cpup(dentry, parent, add_entry, bcpup, bstart);
+ if (err >= 0) {
+ if (d_really_is_negative(dentry)) {
+ au_set_h_dptr(dentry, bstart, NULL);
+ au_set_dbstart(dentry, bcpup);
+ au_set_dbend(dentry, bcpup);
+ }
+ AuDebugOn(add_entry
+ && !au_ftest_wrdir(args->flags, TMPFILE)
+ && !au_h_dptr(dentry, bcpup));
+ }
+
+out:
+ dput(parent);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void au_pin_hdir_unlock(struct au_pin *p)
+{
+ if (p->hdir)
+ au_hn_imtx_unlock(p->hdir);
+}
+
+int au_pin_hdir_lock(struct au_pin *p)
+{
+ int err;
+
+ err = 0;
+ if (!p->hdir)
+ goto out;
+
+ /* even if an error happens later, keep this lock */
+ au_hn_imtx_lock_nested(p->hdir, p->lsc_hi);
+
+ err = -EBUSY;
+ if (unlikely(p->hdir->hi_inode != d_inode(p->h_parent)))
+ goto out;
+
+ err = 0;
+ if (p->h_dentry)
+ err = au_h_verify(p->h_dentry, p->udba, p->hdir->hi_inode,
+ p->h_parent, p->br);
+
+out:
+ return err;
+}
+
+int au_pin_hdir_relock(struct au_pin *p)
+{
+ int err, i;
+ struct inode *h_i;
+ struct dentry *h_d[] = {
+ p->h_dentry,
+ p->h_parent
+ };
+
+ err = au_pin_hdir_lock(p);
+ if (unlikely(err))
+ goto out;
+
+ for (i = 0; !err && i < sizeof(h_d)/sizeof(*h_d); i++) {
+ if (!h_d[i])
+ continue;
+ if (d_is_positive(h_d[i])) {
+ h_i = d_inode(h_d[i]);
+ err = !h_i->i_nlink;
+ }
+ }
+
+out:
+ return err;
+}
+
+void au_pin_hdir_set_owner(struct au_pin *p, struct task_struct *task)
+{
+#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP)
+ p->hdir->hi_inode->i_mutex.owner = task;
+#endif
+}
+
+void au_pin_hdir_acquire_nest(struct au_pin *p)
+{
+ if (p->hdir) {
+ mutex_acquire_nest(&p->hdir->hi_inode->i_mutex.dep_map,
+ p->lsc_hi, 0, NULL, _RET_IP_);
+ au_pin_hdir_set_owner(p, current);
+ }
+}
+
+void au_pin_hdir_release(struct au_pin *p)
+{
+ if (p->hdir) {
+ au_pin_hdir_set_owner(p, p->task);
+ mutex_release(&p->hdir->hi_inode->i_mutex.dep_map, 1, _RET_IP_);
+ }
+}
+
+struct dentry *au_pinned_h_parent(struct au_pin *pin)
+{
+ if (pin && pin->parent)
+ return au_h_dptr(pin->parent, pin->bindex);
+ return NULL;
+}
+
+void au_unpin(struct au_pin *p)
+{
+ if (p->hdir)
+ au_pin_hdir_unlock(p);
+ if (p->h_mnt && au_ftest_pin(p->flags, MNT_WRITE))
+ vfsub_mnt_drop_write(p->h_mnt);
+ if (!p->hdir)
+ return;
+
+ if (!au_ftest_pin(p->flags, DI_LOCKED))
+ di_read_unlock(p->parent, AuLock_IR);
+ iput(p->hdir->hi_inode);
+ dput(p->parent);
+ p->parent = NULL;
+ p->hdir = NULL;
+ p->h_mnt = NULL;
+ /* do not clear p->task */
+}
+
+int au_do_pin(struct au_pin *p)
+{
+ int err;
+ struct super_block *sb;
+ struct inode *h_dir;
+
+ err = 0;
+ sb = p->dentry->d_sb;
+ p->br = au_sbr(sb, p->bindex);
+ if (IS_ROOT(p->dentry)) {
+ if (au_ftest_pin(p->flags, MNT_WRITE)) {
+ p->h_mnt = au_br_mnt(p->br);
+ err = vfsub_mnt_want_write(p->h_mnt);
+ if (unlikely(err)) {
+ au_fclr_pin(p->flags, MNT_WRITE);
+ goto out_err;
+ }
+ }
+ goto out;
+ }
+
+ p->h_dentry = NULL;
+ if (p->bindex <= au_dbend(p->dentry))
+ p->h_dentry = au_h_dptr(p->dentry, p->bindex);
+
+ p->parent = dget_parent(p->dentry);
+ if (!au_ftest_pin(p->flags, DI_LOCKED))
+ di_read_lock(p->parent, AuLock_IR, p->lsc_di);
+
+ h_dir = NULL;
+ p->h_parent = au_h_dptr(p->parent, p->bindex);
+ p->hdir = au_hi(d_inode(p->parent), p->bindex);
+ if (p->hdir)
+ h_dir = p->hdir->hi_inode;
+
+ /*
+ * udba case, or
+ * if DI_LOCKED is not set, then p->parent may be different
+ * and h_parent can be NULL.
+ */
+ if (unlikely(!p->hdir || !h_dir || !p->h_parent)) {
+ err = -EBUSY;
+ if (!au_ftest_pin(p->flags, DI_LOCKED))
+ di_read_unlock(p->parent, AuLock_IR);
+ dput(p->parent);
+ p->parent = NULL;
+ goto out_err;
+ }
+
+ if (au_ftest_pin(p->flags, MNT_WRITE)) {
+ p->h_mnt = au_br_mnt(p->br);
+ err = vfsub_mnt_want_write(p->h_mnt);
+ if (unlikely(err)) {
+ au_fclr_pin(p->flags, MNT_WRITE);
+ if (!au_ftest_pin(p->flags, DI_LOCKED))
+ di_read_unlock(p->parent, AuLock_IR);
+ dput(p->parent);
+ p->parent = NULL;
+ goto out_err;
+ }
+ }
+
+ au_igrab(h_dir);
+ err = au_pin_hdir_lock(p);
+ if (!err)
+ goto out; /* success */
+
+ au_unpin(p);
+
+out_err:
+ pr_err("err %d\n", err);
+ err = au_busy_or_stale();
+out:
+ return err;
+}
+
+void au_pin_init(struct au_pin *p, struct dentry *dentry,
+ aufs_bindex_t bindex, int lsc_di, int lsc_hi,
+ unsigned int udba, unsigned char flags)
+{
+ p->dentry = dentry;
+ p->udba = udba;
+ p->lsc_di = lsc_di;
+ p->lsc_hi = lsc_hi;
+ p->flags = flags;
+ p->bindex = bindex;
+
+ p->parent = NULL;
+ p->hdir = NULL;
+ p->h_mnt = NULL;
+
+ p->h_dentry = NULL;
+ p->h_parent = NULL;
+ p->br = NULL;
+ p->task = current;
+}
+
+int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
+ unsigned int udba, unsigned char flags)
+{
+ au_pin_init(pin, dentry, bindex, AuLsc_DI_PARENT, AuLsc_I_PARENT2,
+ udba, flags);
+ return au_do_pin(pin);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * ->setattr() and ->getattr() are called in various cases.
+ * chmod, stat: dentry is revalidated.
+ * fchmod, fstat: file and dentry are not revalidated, additionally they may be
+ * unhashed.
+ * for ->setattr(), ia->ia_file is passed from ftruncate only.
+ */
+/* todo: consolidate with do_refresh() and simple_reval_dpath() */
+int au_reval_for_attr(struct dentry *dentry, unsigned int sigen)
+{
+ int err;
+ struct dentry *parent;
+
+ err = 0;
+ if (au_digen_test(dentry, sigen)) {
+ parent = dget_parent(dentry);
+ di_read_lock_parent(parent, AuLock_IR);
+ err = au_refresh_dentry(dentry, parent);
+ di_read_unlock(parent, AuLock_IR);
+ dput(parent);
+ }
+
+ AuTraceErr(err);
+ return err;
+}
+
+int au_pin_and_icpup(struct dentry *dentry, struct iattr *ia,
+ struct au_icpup_args *a)
+{
+ int err;
+ loff_t sz;
+ aufs_bindex_t bstart, ibstart;
+ struct dentry *hi_wh, *parent;
+ struct inode *inode;
+ struct au_wr_dir_args wr_dir_args = {
+ .force_btgt = -1,
+ .flags = 0
+ };
+
+ if (d_is_dir(dentry))
+ au_fset_wrdir(wr_dir_args.flags, ISDIR);
+ /* plink or hi_wh() case */
+ bstart = au_dbstart(dentry);
+ inode = d_inode(dentry);
+ ibstart = au_ibstart(inode);
+ if (bstart != ibstart && !au_test_ro(inode->i_sb, ibstart, inode))
+ wr_dir_args.force_btgt = ibstart;
+ err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args);
+ if (unlikely(err < 0))
+ goto out;
+ a->btgt = err;
+ if (err != bstart)
+ au_fset_icpup(a->flags, DID_CPUP);
+
+ err = 0;
+ a->pin_flags = AuPin_MNT_WRITE;
+ parent = NULL;
+ if (!IS_ROOT(dentry)) {
+ au_fset_pin(a->pin_flags, DI_LOCKED);
+ parent = dget_parent(dentry);
+ di_write_lock_parent(parent);
+ }
+
+ err = au_pin(&a->pin, dentry, a->btgt, a->udba, a->pin_flags);
+ if (unlikely(err))
+ goto out_parent;
+
+ a->h_path.dentry = au_h_dptr(dentry, bstart);
+ sz = -1;
+ a->h_inode = d_inode(a->h_path.dentry);
+ if (ia && (ia->ia_valid & ATTR_SIZE)) {
+ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
+ if (ia->ia_size < i_size_read(a->h_inode))
+ sz = ia->ia_size;
+ mutex_unlock(&a->h_inode->i_mutex);
+ }
+
+ hi_wh = NULL;
+ if (au_ftest_icpup(a->flags, DID_CPUP) && d_unlinked(dentry)) {
+ hi_wh = au_hi_wh(inode, a->btgt);
+ if (!hi_wh) {
+ struct au_cp_generic cpg = {
+ .dentry = dentry,
+ .bdst = a->btgt,
+ .bsrc = -1,
+ .len = sz,
+ .pin = &a->pin
+ };
+ err = au_sio_cpup_wh(&cpg, /*file*/NULL);
+ if (unlikely(err))
+ goto out_unlock;
+ hi_wh = au_hi_wh(inode, a->btgt);
+ /* todo: revalidate hi_wh? */
+ }
+ }
+
+ if (parent) {
+ au_pin_set_parent_lflag(&a->pin, /*lflag*/0);
+ di_downgrade_lock(parent, AuLock_IR);
+ dput(parent);
+ parent = NULL;
+ }
+ if (!au_ftest_icpup(a->flags, DID_CPUP))
+ goto out; /* success */
+
+ if (!d_unhashed(dentry)) {
+ struct au_cp_generic cpg = {
+ .dentry = dentry,
+ .bdst = a->btgt,
+ .bsrc = bstart,
+ .len = sz,
+ .pin = &a->pin,
+ .flags = AuCpup_DTIME | AuCpup_HOPEN
+ };
+ err = au_sio_cpup_simple(&cpg);
+ if (!err)
+ a->h_path.dentry = au_h_dptr(dentry, a->btgt);
+ } else if (!hi_wh)
+ a->h_path.dentry = au_h_dptr(dentry, a->btgt);
+ else
+ a->h_path.dentry = hi_wh; /* do not dget here */
+
+out_unlock:
+ a->h_inode = d_inode(a->h_path.dentry);
+ if (!err)
+ goto out; /* success */
+ au_unpin(&a->pin);
+out_parent:
+ if (parent) {
+ di_write_unlock(parent);
+ dput(parent);
+ }
+out:
+ if (!err)
+ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
+ return err;
+}
+
+static int aufs_setattr(struct dentry *dentry, struct iattr *ia)
+{
+ int err;
+ struct inode *inode, *delegated;
+ struct super_block *sb;
+ struct file *file;
+ struct au_icpup_args *a;
+
+ inode = d_inode(dentry);
+ IMustLock(inode);
+
+ err = -ENOMEM;
+ a = kzalloc(sizeof(*a), GFP_NOFS);
+ if (unlikely(!a))
+ goto out;
+
+ if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ ia->ia_valid &= ~ATTR_MODE;
+
+ file = NULL;
+ sb = dentry->d_sb;
+ err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
+ if (unlikely(err))
+ goto out_kfree;
+
+ if (ia->ia_valid & ATTR_FILE) {
+ /* currently ftruncate(2) only */
+ AuDebugOn(!d_is_reg(dentry));
+ file = ia->ia_file;
+ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
+ if (unlikely(err))
+ goto out_si;
+ ia->ia_file = au_hf_top(file);
+ a->udba = AuOpt_UDBA_NONE;
+ } else {
+ /* fchmod() doesn't pass ia_file */
+ a->udba = au_opt_udba(sb);
+ di_write_lock_child(dentry);
+ /* no d_unlinked(), to set UDBA_NONE for root */
+ if (d_unhashed(dentry))
+ a->udba = AuOpt_UDBA_NONE;
+ if (a->udba != AuOpt_UDBA_NONE) {
+ AuDebugOn(IS_ROOT(dentry));
+ err = au_reval_for_attr(dentry, au_sigen(sb));
+ if (unlikely(err))
+ goto out_dentry;
+ }
+ }
+
+ err = au_pin_and_icpup(dentry, ia, a);
+ if (unlikely(err < 0))
+ goto out_dentry;
+ if (au_ftest_icpup(a->flags, DID_CPUP)) {
+ ia->ia_file = NULL;
+ ia->ia_valid &= ~ATTR_FILE;
+ }
+
+ a->h_path.mnt = au_sbr_mnt(sb, a->btgt);
+ if ((ia->ia_valid & (ATTR_MODE | ATTR_CTIME))
+ == (ATTR_MODE | ATTR_CTIME)) {
+ err = security_path_chmod(&a->h_path, ia->ia_mode);
+ if (unlikely(err))
+ goto out_unlock;
+ } else if ((ia->ia_valid & (ATTR_UID | ATTR_GID))
+ && (ia->ia_valid & ATTR_CTIME)) {
+ err = security_path_chown(&a->h_path, ia->ia_uid, ia->ia_gid);
+ if (unlikely(err))
+ goto out_unlock;
+ }
+
+ if (ia->ia_valid & ATTR_SIZE) {
+ struct file *f;
+
+ if (ia->ia_size < i_size_read(inode))
+ /* unmap only */
+ truncate_setsize(inode, ia->ia_size);
+
+ f = NULL;
+ if (ia->ia_valid & ATTR_FILE)
+ f = ia->ia_file;
+ mutex_unlock(&a->h_inode->i_mutex);
+ err = vfsub_trunc(&a->h_path, ia->ia_size, ia->ia_valid, f);
+ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
+ } else {
+ delegated = NULL;
+ while (1) {
+ err = vfsub_notify_change(&a->h_path, ia, &delegated);
+ if (delegated) {
+ err = break_deleg_wait(&delegated);
+ if (!err)
+ continue;
+ }
+ break;
+ }
+ }
+ if (!err)
+ au_cpup_attr_changeable(inode);
+
+out_unlock:
+ mutex_unlock(&a->h_inode->i_mutex);
+ au_unpin(&a->pin);
+ if (unlikely(err))
+ au_update_dbstart(dentry);
+out_dentry:
+ di_write_unlock(dentry);
+ if (file) {
+ fi_write_unlock(file);
+ ia->ia_file = file;
+ ia->ia_valid |= ATTR_FILE;
+ }
+out_si:
+ si_read_unlock(sb);
+out_kfree:
+ kfree(a);
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+#if IS_ENABLED(CONFIG_AUFS_XATTR) || IS_ENABLED(CONFIG_FS_POSIX_ACL)
+static int au_h_path_to_set_attr(struct dentry *dentry,
+ struct au_icpup_args *a, struct path *h_path)
+{
+ int err;
+ struct super_block *sb;
+
+ sb = dentry->d_sb;
+ a->udba = au_opt_udba(sb);
+ /* no d_unlinked(), to set UDBA_NONE for root */
+ if (d_unhashed(dentry))
+ a->udba = AuOpt_UDBA_NONE;
+ if (a->udba != AuOpt_UDBA_NONE) {
+ AuDebugOn(IS_ROOT(dentry));
+ err = au_reval_for_attr(dentry, au_sigen(sb));
+ if (unlikely(err))
+ goto out;
+ }
+ err = au_pin_and_icpup(dentry, /*ia*/NULL, a);
+ if (unlikely(err < 0))
+ goto out;
+
+ h_path->dentry = a->h_path.dentry;
+ h_path->mnt = au_sbr_mnt(sb, a->btgt);
+
+out:
+ return err;
+}
+
+ssize_t au_srxattr(struct dentry *dentry, struct au_srxattr *arg)
+{
+ int err;
+ struct path h_path;
+ struct super_block *sb;
+ struct au_icpup_args *a;
+ struct inode *inode, *h_inode;
+
+ inode = d_inode(dentry);
+ IMustLock(inode);
+
+ err = -ENOMEM;
+ a = kzalloc(sizeof(*a), GFP_NOFS);
+ if (unlikely(!a))
+ goto out;
+
+ sb = dentry->d_sb;
+ err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
+ if (unlikely(err))
+ goto out_kfree;
+
+ h_path.dentry = NULL; /* silence gcc */
+ di_write_lock_child(dentry);
+ err = au_h_path_to_set_attr(dentry, a, &h_path);
+ if (unlikely(err))
+ goto out_di;
+
+ mutex_unlock(&a->h_inode->i_mutex);
+ switch (arg->type) {
+ case AU_XATTR_SET:
+ err = vfsub_setxattr(h_path.dentry,
+ arg->u.set.name, arg->u.set.value,
+ arg->u.set.size, arg->u.set.flags);
+ break;
+ case AU_XATTR_REMOVE:
+ err = vfsub_removexattr(h_path.dentry, arg->u.remove.name);
+ break;
+ case AU_ACL_SET:
+ err = -EOPNOTSUPP;
+ h_inode = d_inode(h_path.dentry);
+ if (h_inode->i_op->set_acl)
+ err = h_inode->i_op->set_acl(h_inode,
+ arg->u.acl_set.acl,
+ arg->u.acl_set.type);
+ break;
+ }
+ if (!err)
+ au_cpup_attr_timesizes(inode);
+
+ au_unpin(&a->pin);
+ if (unlikely(err))
+ au_update_dbstart(dentry);
+
+out_di:
+ di_write_unlock(dentry);
+ si_read_unlock(sb);
+out_kfree:
+ kfree(a);
+out:
+ AuTraceErr(err);
+ return err;
+}
+#endif
+
+static void au_refresh_iattr(struct inode *inode, struct kstat *st,
+ unsigned int nlink)
+{
+ unsigned int n;
+
+ inode->i_mode = st->mode;
+ /* don't i_[ug]id_write() here */
+ inode->i_uid = st->uid;
+ inode->i_gid = st->gid;
+ inode->i_atime = st->atime;
+ inode->i_mtime = st->mtime;
+ inode->i_ctime = st->ctime;
+
+ au_cpup_attr_nlink(inode, /*force*/0);
+ if (S_ISDIR(inode->i_mode)) {
+ n = inode->i_nlink;
+ n -= nlink;
+ n += st->nlink;
+ smp_mb(); /* for i_nlink */
+ /* 0 can happen */
+ set_nlink(inode, n);
+ }
+
+ spin_lock(&inode->i_lock);
+ inode->i_blocks = st->blocks;
+ i_size_write(inode, st->size);
+ spin_unlock(&inode->i_lock);
+}
+
+/*
+ * common routine for aufs_getattr() and aufs_getxattr().
+ * returns zero or negative (an error).
+ * @dentry will be read-locked in success.
+ */
+int au_h_path_getattr(struct dentry *dentry, int force, struct path *h_path)
+{
+ int err;
+ unsigned int mnt_flags, sigen;
+ unsigned char udba_none;
+ aufs_bindex_t bindex;
+ struct super_block *sb, *h_sb;
+ struct inode *inode;
+
+ h_path->mnt = NULL;
+ h_path->dentry = NULL;
+
+ err = 0;
+ sb = dentry->d_sb;
+ mnt_flags = au_mntflags(sb);
+ udba_none = !!au_opt_test(mnt_flags, UDBA_NONE);
+
+ /* support fstat(2) */
+ if (!d_unlinked(dentry) && !udba_none) {
+ sigen = au_sigen(sb);
+ err = au_digen_test(dentry, sigen);
+ if (!err) {
+ di_read_lock_child(dentry, AuLock_IR);
+ err = au_dbrange_test(dentry);
+ if (unlikely(err)) {
+ di_read_unlock(dentry, AuLock_IR);
+ goto out;
+ }
+ } else {
+ AuDebugOn(IS_ROOT(dentry));
+ di_write_lock_child(dentry);
+ err = au_dbrange_test(dentry);
+ if (!err)
+ err = au_reval_for_attr(dentry, sigen);
+ if (!err)
+ di_downgrade_lock(dentry, AuLock_IR);
+ else {
+ di_write_unlock(dentry);
+ goto out;
+ }
+ }
+ } else
+ di_read_lock_child(dentry, AuLock_IR);
+
+ inode = d_inode(dentry);
+ bindex = au_ibstart(inode);
+ h_path->mnt = au_sbr_mnt(sb, bindex);
+ h_sb = h_path->mnt->mnt_sb;
+ if (!force
+ && !au_test_fs_bad_iattr(h_sb)
+ && udba_none)
+ goto out; /* success */
+
+ if (au_dbstart(dentry) == bindex)
+ h_path->dentry = au_h_dptr(dentry, bindex);
+ else if (au_opt_test(mnt_flags, PLINK) && au_plink_test(inode)) {
+ h_path->dentry = au_plink_lkup(inode, bindex);
+ if (IS_ERR(h_path->dentry))
+ /* pretending success */
+ h_path->dentry = NULL;
+ else
+ dput(h_path->dentry);
+ }
+
+out:
+ return err;
+}
+
+static int aufs_getattr(struct vfsmount *mnt __maybe_unused,
+ struct dentry *dentry, struct kstat *st)
+{
+ int err;
+ unsigned char positive;
+ struct path h_path;
+ struct inode *inode;
+ struct super_block *sb;
+
+ inode = d_inode(dentry);
+ sb = dentry->d_sb;
+ err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
+ if (unlikely(err))
+ goto out;
+ err = au_h_path_getattr(dentry, /*force*/0, &h_path);
+ if (unlikely(err))
+ goto out_si;
+ if (unlikely(!h_path.dentry))
+ /* illegally overlapped or something */
+ goto out_fill; /* pretending success */
+
+ positive = d_is_positive(h_path.dentry);
+ if (positive)
+ err = vfs_getattr(&h_path, st);
+ if (!err) {
+ if (positive)
+ au_refresh_iattr(inode, st,
+ d_inode(h_path.dentry)->i_nlink);
+ goto out_fill; /* success */
+ }
+ AuTraceErr(err);
+ goto out_di;
+
+out_fill:
+ generic_fillattr(inode, st);
+out_di:
+ di_read_unlock(dentry, AuLock_IR);
+out_si:
+ si_read_unlock(sb);
+out:
+ AuTraceErr(err);
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int h_readlink(struct dentry *dentry, int bindex, char __user *buf,
+ int bufsiz)
+{
+ int err;
+ struct super_block *sb;
+ struct dentry *h_dentry;
+ struct inode *inode, *h_inode;
+
+ err = -EINVAL;
+ h_dentry = au_h_dptr(dentry, bindex);
+ h_inode = d_inode(h_dentry);
+ if (unlikely(!h_inode->i_op->readlink))
+ goto out;
+
+ err = security_inode_readlink(h_dentry);
+ if (unlikely(err))
+ goto out;
+
+ sb = dentry->d_sb;
+ inode = d_inode(dentry);
+ if (!au_test_ro(sb, bindex, inode)) {
+ vfsub_touch_atime(au_sbr_mnt(sb, bindex), h_dentry);
+ fsstack_copy_attr_atime(inode, h_inode);
+ }
+ err = h_inode->i_op->readlink(h_dentry, buf, bufsiz);
+
+out:
+ return err;
+}
+
+static int aufs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+ int err;
+
+ err = aufs_read_lock(dentry, AuLock_IR | AuLock_GEN);
+ if (unlikely(err))
+ goto out;
+ err = au_d_hashed_positive(dentry);
+ if (!err)
+ err = h_readlink(dentry, au_dbstart(dentry), buf, bufsiz);
+ aufs_read_unlock(dentry, AuLock_IR);
+
+out:
+ return err;
+}
+
+static void *aufs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ int err;
+ mm_segment_t old_fs;
+ union {
+ char *k;
+ char __user *u;
+ } buf;
+
+ err = -ENOMEM;
+ buf.k = (void *)__get_free_page(GFP_NOFS);
+ if (unlikely(!buf.k))
+ goto out;
+
+ err = aufs_read_lock(dentry, AuLock_IR | AuLock_GEN);
+ if (unlikely(err))
+ goto out_name;
+
+ err = au_d_hashed_positive(dentry);
+ if (!err) {
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ err = h_readlink(dentry, au_dbstart(dentry), buf.u, PATH_MAX);
+ set_fs(old_fs);
+ }
+ aufs_read_unlock(dentry, AuLock_IR);
+
+ if (err >= 0) {
+ buf.k[err] = 0;
+ /* will be freed by put_link */
+ nd_set_link(nd, buf.k);
+ return NULL; /* success */
+ }
+
+out_name:
+ free_page((unsigned long)buf.k);
+out:
+ AuTraceErr(err);
+ return ERR_PTR(err);
+}
+
+static void aufs_put_link(struct dentry *dentry __maybe_unused,
+ struct nameidata *nd, void *cookie __maybe_unused)
+{
+ char *p;
+
+ p = nd_get_link(nd);
+ if (!IS_ERR_OR_NULL(p))
+ free_page((unsigned long)p);
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int aufs_update_time(struct inode *inode, struct timespec *ts, int flags)
+{
+ int err;
+ struct super_block *sb;
+ struct inode *h_inode;
+
+ sb = inode->i_sb;
+ /* mmap_sem might be acquired already, cf. aufs_mmap() */
+ lockdep_off();
+ si_read_lock(sb, AuLock_FLUSH);
+ ii_write_lock_child(inode);
+ lockdep_on();
+ h_inode = au_h_iptr(inode, au_ibstart(inode));
+ err = vfsub_update_time(h_inode, ts, flags);
+ lockdep_off();
+ if (!err)
+ au_cpup_attr_timesizes(inode);
+ ii_write_unlock(inode);
+ si_read_unlock(sb);
+ lockdep_on();
+
+ if (!err && (flags & S_VERSION))
+ inode_inc_iversion(inode);
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct inode_operations aufs_symlink_iop = {
+ .permission = aufs_permission,
+#ifdef CONFIG_FS_POSIX_ACL
+ .get_acl = aufs_get_acl,
+ .set_acl = aufs_set_acl, /* unsupport for symlink? */
+#endif
+
+ .setattr = aufs_setattr,
+ .getattr = aufs_getattr,
+
+#ifdef CONFIG_AUFS_XATTR
+ .setxattr = aufs_setxattr,
+ .getxattr = aufs_getxattr,
+ .listxattr = aufs_listxattr,
+ .removexattr = aufs_removexattr,
+#endif
+
+ .readlink = aufs_readlink,
+ .follow_link = aufs_follow_link,
+ .put_link = aufs_put_link,
+
+ /* .update_time = aufs_update_time */
+};
+
+struct inode_operations aufs_dir_iop = {
+ .create = aufs_create,
+ .lookup = aufs_lookup,
+ .link = aufs_link,
+ .unlink = aufs_unlink,
+ .symlink = aufs_symlink,
+ .mkdir = aufs_mkdir,
+ .rmdir = aufs_rmdir,
+ .mknod = aufs_mknod,
+ .rename = aufs_rename,
+
+ .permission = aufs_permission,
+#ifdef CONFIG_FS_POSIX_ACL
+ .get_acl = aufs_get_acl,
+ .set_acl = aufs_set_acl,
+#endif
+
+ .setattr = aufs_setattr,
+ .getattr = aufs_getattr,
+
+#ifdef CONFIG_AUFS_XATTR
+ .setxattr = aufs_setxattr,
+ .getxattr = aufs_getxattr,
+ .listxattr = aufs_listxattr,
+ .removexattr = aufs_removexattr,
+#endif
+
+ .update_time = aufs_update_time,
+ .atomic_open = aufs_atomic_open,
+ .tmpfile = aufs_tmpfile
+};
+
+struct inode_operations aufs_iop = {
+ .permission = aufs_permission,
+#ifdef CONFIG_FS_POSIX_ACL
+ .get_acl = aufs_get_acl,
+ .set_acl = aufs_set_acl,
+#endif
+
+ .setattr = aufs_setattr,
+ .getattr = aufs_getattr,
+
+#ifdef CONFIG_AUFS_XATTR
+ .setxattr = aufs_setxattr,
+ .getxattr = aufs_getxattr,
+ .listxattr = aufs_listxattr,
+ .removexattr = aufs_removexattr,
+#endif
+
+ .update_time = aufs_update_time
+};