/* common functions to regular file and dir */
struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
struct file *file, int force_wr)
{
struct file *h_file;
struct dentry *h_dentry;
struct inode *h_inode;
struct super_block *sb;
struct au_branch *br;
struct path h_path;
int err, exec_flag;
/* a race condition can happen between open and unlink/rmdir */
h_file = ERR_PTR(-ENOENT);
h_dentry = au_h_dptr(dentry, bindex);
if (au_test_nfsd() && !h_dentry)
goto out;
h_inode = h_dentry->d_inode;
if (au_test_nfsd() && !h_inode)
goto out;
spin_lock(&h_dentry->d_lock);
err = (!d_unhashed(dentry) && d_unlinked(h_dentry))
|| !h_inode
/* || !dentry->d_inode->i_nlink */
;
spin_unlock(&h_dentry->d_lock);
if (unlikely(err))
goto out;
sb = dentry->d_sb;
br = au_sbr(sb, bindex);
h_file = ERR_PTR(-EACCES);
exec_flag = flags & __FMODE_EXEC;
if (exec_flag && (au_br_mnt(br)->mnt_flags & MNT_NOEXEC))
goto out;
/* drop flags for writing */
if (au_test_ro(sb, bindex, dentry->d_inode)) {
if (force_wr && !(flags & O_WRONLY))
force_wr = 0;
flags = au_file_roflags(flags);
if (force_wr) {
h_file = ERR_PTR(-EROFS);
flags = au_file_roflags(flags);
if (unlikely(vfsub_native_ro(h_inode)
|| IS_APPEND(h_inode)))
goto out;
flags &= ~O_ACCMODE;
flags |= O_WRONLY;
}
}
flags &= ~O_CREAT;
atomic_inc(&br->br_count);
h_path.dentry = h_dentry;
h_path.mnt = au_br_mnt(br);
if (!au_special_file(h_inode->i_mode))
h_file = vfsub_dentry_open(&h_path, flags);
else {
/* this block depends upon the configuration */
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
si_read_unlock(sb);
h_file = vfsub_dentry_open(&h_path, flags);
si_noflush_read_lock(sb);
fi_write_lock(file);
di_read_lock_child(dentry, AuLock_IR);
}
if (IS_ERR(h_file))
goto out_br;
if (exec_flag) {
err = deny_write_access(h_file);
if (unlikely(err)) {
fput(h_file);
h_file = ERR_PTR(err);
goto out_br;
}
}
fsnotify_open(h_file);
goto out; /* success */
out_br:
atomic_dec(&br->br_count);
out:
return h_file;
}
static int au_mvd_args(const unsigned char dmsg, struct au_mvd_args *a)
{
int err;
struct au_branch *br;
err = -EISDIR;
if (unlikely(S_ISDIR(a->inode->i_mode)))
goto out;
err = -EINVAL;
if (!(a->mvdown.flags & AUFS_MVDOWN_BRID_UPPER))
a->mvd_bsrc = au_ibstart(a->inode);
else {
a->mvd_bsrc = au_br_index(a->sb, a->mvd_src_brid);
if (unlikely(a->mvd_bsrc < 0
|| (a->mvd_bsrc < au_dbstart(a->dentry)
|| au_dbend(a->dentry) < a->mvd_bsrc
|| !au_h_dptr(a->dentry, a->mvd_bsrc))
|| (a->mvd_bsrc < au_ibstart(a->inode)
|| au_ibend(a->inode) < a->mvd_bsrc
|| !au_h_iptr(a->inode, a->mvd_bsrc)))) {
a->mvd_errno = EAU_MVDOWN_NOUPPER;
AU_MVD_PR(dmsg, "no upper\n");
goto out;
}
}
if (unlikely(a->mvd_bsrc == au_sbend(a->sb))) {
a->mvd_errno = EAU_MVDOWN_BOTTOM;
AU_MVD_PR(dmsg, "on the bottom\n");
goto out;
}
a->mvd_h_src_inode = au_h_iptr(a->inode, a->mvd_bsrc);
br = au_sbr(a->sb, a->mvd_bsrc);
err = au_br_rdonly(br);
if (!(a->mvdown.flags & AUFS_MVDOWN_ROUPPER)) {
if (unlikely(err))
goto out;
} else if (!(vfsub_native_ro(a->mvd_h_src_inode)
|| IS_APPEND(a->mvd_h_src_inode))) {
if (err)
a->mvdown.flags |= AUFS_MVDOWN_ROUPPER_R;
/* go on */
} else
goto out;
err = -EINVAL;
if (!(a->mvdown.flags & AUFS_MVDOWN_BRID_LOWER)) {
a->mvd_bdst = find_lower_writable(a);
if (unlikely(a->mvd_bdst < 0)) {
a->mvd_errno = EAU_MVDOWN_BOTTOM;
AU_MVD_PR(dmsg, "no writable lower branch\n");
goto out;
}
} else {
a->mvd_bdst = au_br_index(a->sb, a->mvd_dst_brid);
if (unlikely(a->mvd_bdst < 0
|| au_sbend(a->sb) < a->mvd_bdst)) {
a->mvd_errno = EAU_MVDOWN_NOLOWERBR;
AU_MVD_PR(dmsg, "no lower brid\n");
goto out;
}
}
err = au_mvd_args_busy(dmsg, a);
if (!err)
err = au_mvd_args_parent(dmsg, a);
if (!err)
err = au_mvd_args_intermediate(dmsg, a);
if (!err)
err = au_mvd_args_exist(dmsg, a);
if (!err)
AuDbg("b%d, b%d\n", a->mvd_bsrc, a->mvd_bdst);
out:
AuTraceErr(err);
return err;
}
/* common functions to regular file and dir */
struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
struct file *file, int force_wr)
{
struct file *h_file;
struct dentry *h_dentry;
struct inode *h_inode;
struct super_block *sb;
struct au_branch *br;
struct path h_path;
int err;
/* a race condition can happen between open and unlink/rmdir */
h_file = ERR_PTR(-ENOENT);
h_dentry = au_h_dptr(dentry, bindex);
if (au_test_nfsd() && !h_dentry)
goto out;
h_inode = h_dentry->d_inode;
if (au_test_nfsd() && !h_inode)
goto out;
spin_lock(&h_dentry->d_lock);
err = (!d_unhashed(dentry) && d_unlinked(h_dentry))
|| !h_inode
/* || !dentry->d_inode->i_nlink */
;
spin_unlock(&h_dentry->d_lock);
if (unlikely(err))
goto out;
sb = dentry->d_sb;
br = au_sbr(sb, bindex);
err = au_br_test_oflag(flags, br);
h_file = ERR_PTR(err);
if (unlikely(err))
goto out;
/* drop flags for writing */
if (au_test_ro(sb, bindex, dentry->d_inode)) {
if (force_wr && !(flags & O_WRONLY))
force_wr = 0;
flags = au_file_roflags(flags);
if (force_wr) {
h_file = ERR_PTR(-EROFS);
flags = au_file_roflags(flags);
if (unlikely(vfsub_native_ro(h_inode)
|| IS_APPEND(h_inode)))
goto out;
flags &= ~O_ACCMODE;
flags |= O_WRONLY;
}
}
flags &= ~O_CREAT;
atomic_inc(&br->br_count);
h_path.dentry = h_dentry;
h_path.mnt = au_br_mnt(br);
h_file = vfsub_dentry_open(&h_path, flags);
if (IS_ERR(h_file))
goto out_br;
if (flags & __FMODE_EXEC) {
err = deny_write_access(h_file);
if (unlikely(err)) {
fput(h_file);
h_file = ERR_PTR(err);
goto out_br;
}
}
fsnotify_open(h_file);
goto out; /* success */
out_br:
atomic_dec(&br->br_count);
out:
return h_file;
}
