[PATCH 42/67] aufs directory operations, source

[hooanon05@yahoo.co.jp]

From: Junjiro Okajima <hooanon05@yahoo.co.jp>

	initial commit
	aufs directory operations, source

Signed-off-by: Junjiro Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/dir.c |  573 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 573 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/dir.c b/fs/aufs/dir.c
new file mode 100644
index 0000000..e9dac57
--- /dev/null
+++ b/fs/aufs/dir.c
@@ -0,0 +1,573 @@
+/*
+ * 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
+ */
+
+/*
+ * directory operations
+ *
+ * $Id: dir.c,v 1.4 2008/05/12 00:27:58 sfjro Exp $
+ */
+
+#include <linux/fs_stack.h>
+#include "aufs.h"
+
+static int reopen_dir(struct file *file)
+{
+	int err;
+	struct dentry *dentry, *h_dentry;
+	aufs_bindex_t bindex, btail, bstart;
+	struct file *h_file;
+
+	dentry = file->f_dentry;
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
+
+	/* open all hidden dirs */
+	bstart = au_dbstart(dentry);
+#if 1
+	for (bindex = au_fbstart(file); bindex < bstart; bindex++)
+		au_set_h_fptr(file, bindex, NULL);
+#endif
+	au_set_fbstart(file, bstart);
+	btail = au_dbtaildir(dentry);
+#if 1
+	for (bindex = au_fbend(file); btail < bindex; bindex--)
+		au_set_h_fptr(file, bindex, NULL);
+#endif
+	au_set_fbend(file, btail);
+	for (bindex = bstart; bindex <= btail; bindex++) {
+		h_dentry = au_h_dptr(dentry, bindex);
+		if (!h_dentry)
+			continue;
+		h_file = au_h_fptr(file, bindex);
+		if (h_file) {
+			AuDebugOn(h_file->f_dentry != h_dentry);
+			continue;
+		}
+
+		h_file = au_h_open(dentry, bindex, file->f_flags, file);
+		// unavailable
+		//if (LktrCond) {fput(h_file);
+		//au_br_put(au_sbr(dentry->d_sb, bindex));h_file=ERR_PTR(-1);}
+		err = PTR_ERR(h_file);
+		if (IS_ERR(h_file))
+			goto out; // close all?
+		//cpup_file_flags(h_file, file);
+		au_set_h_fptr(file, bindex, h_file);
+	}
+	au_update_figen(file);
+	//file->f_ra = h_file->f_ra; //??
+	err = 0;
+
+ out:
+	AuTraceErr(err);
+	return err;
+}
+
+static int do_open_dir(struct file *file, int flags)
+{
+	int err;
+	aufs_bindex_t bindex, btail;
+	struct dentry *dentry, *h_dentry;
+	struct file *h_file;
+
+	dentry = file->f_dentry;
+	LKTRTrace("%.*s, 0x%x\n", AuDLNPair(dentry), flags);
+	AuDebugOn(!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode));
+
+	err = 0;
+	au_set_fvdir_cache(file, NULL);
+	file->f_version = dentry->d_inode->i_version;
+	bindex = au_dbstart(dentry);
+	au_set_fbstart(file, bindex);
+	btail = au_dbtaildir(dentry);
+	au_set_fbend(file, btail);
+	for (; !err && bindex <= btail; bindex++) {
+		h_dentry = au_h_dptr(dentry, bindex);
+		if (!h_dentry)
+			continue;
+
+		h_file = au_h_open(dentry, bindex, flags, file);
+		//if (LktrCond) {fput(h_file);
+		//au_br_put(au_sbr(dentry->d_sb, bindex));h_file=ERR_PTR(-1);}
+		if (!IS_ERR(h_file)) {
+			au_set_h_fptr(file, bindex, h_file);
+			continue;
+		}
+		err = PTR_ERR(h_file);
+	}
+	au_update_figen(file);
+	//file->f_ra = h_file->f_ra; //??
+	if (!err)
+		return 0; /* success */
+
+	/* close all */
+	for (bindex = au_fbstart(file); !err && bindex <= btail; bindex++)
+		au_set_h_fptr(file, bindex, NULL);
+	au_set_fbstart(file, -1);
+	au_set_fbend(file, -1);
+	return err;
+}
+
+static int aufs_open_dir(struct inode *inode, struct file *file)
+{
+	return au_do_open(inode, file, do_open_dir);
+}
+
+static int aufs_release_dir(struct inode *inode, struct file *file)
+{
+	struct au_vdir *vdir_cache;
+	struct super_block *sb;
+
+	LKTRTrace("i%lu, %.*s\n", inode->i_ino, AuDLNPair(file->f_dentry));
+
+	sb = file->f_dentry->d_sb;
+	si_noflush_read_lock(sb);
+	fi_write_lock(file);
+	vdir_cache = au_fvdir_cache(file);
+	if (vdir_cache)
+		au_vdir_free(vdir_cache);
+	fi_write_unlock(file);
+	au_finfo_fin(file);
+	si_read_unlock(sb);
+	return 0;
+}
+
+static int fsync_dir(struct dentry *dentry, int datasync)
+{
+	int err;
+	struct inode *inode;
+	struct super_block *sb;
+	aufs_bindex_t bend, bindex;
+
+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), datasync);
+	DiMustAnyLock(dentry);
+	sb = dentry->d_sb;
+	SiMustAnyLock(sb);
+	inode = dentry->d_inode;
+	IMustLock(inode);
+	IiMustAnyLock(inode);
+
+	err = 0;
+	bend = au_dbend(dentry);
+	for (bindex = au_dbstart(dentry); !err && bindex <= bend; bindex++) {
+		struct dentry *h_dentry;
+		struct inode *h_inode;
+		struct file_operations *fop;
+
+		if (au_test_ro(sb, bindex, inode))
+			continue;
+		h_dentry = au_h_dptr(dentry, bindex);
+		if (!h_dentry)
+			continue;
+		h_inode = h_dentry->d_inode;
+		if (!h_inode)
+			continue;
+
+		/* cf. fs/nsfd/vfs.c and fs/nfsd/nfs4recover.c */
+		//au_hdir_lock(h_inode, inode, bindex);
+		mutex_lock(&h_inode->i_mutex);
+		fop = (void *)h_inode->i_fop;
+		err = filemap_fdatawrite(h_inode->i_mapping);
+		if (!err && fop && fop->fsync)
+			err = fop->fsync(NULL, h_dentry, datasync);
+		if (!err)
+			err = filemap_fdatawrite(h_inode->i_mapping);
+		if (!err)
+			au_update_fuse_h_inode(NULL, h_dentry); /*ignore*/
+		//au_hdir_unlock(h_inode, inode, bindex);
+		mutex_unlock(&h_inode->i_mutex);
+	}
+
+	AuTraceErr(err);
+	return err;
+}
+
+/*
+ * @file may be NULL
+ */
+static int aufs_fsync_dir(struct file *file, struct dentry *dentry,
+			  int datasync)
+{
+	int err;
+	struct inode *inode;
+	struct file *h_file;
+	struct super_block *sb;
+	aufs_bindex_t bend, bindex;
+
+	LKTRTrace("%.*s, %d\n", AuDLNPair(dentry), datasync);
+	inode = dentry->d_inode;
+	IMustLock(inode);
+
+	err = 0;
+	sb = dentry->d_sb;
+	si_noflush_read_lock(sb);
+	if (file) {
+		err = au_reval_and_lock_finfo(file, reopen_dir, /*wlock*/1,
+					      /*locked*/1);
+		//err = -1;
+		if (unlikely(err))
+			goto out;
+	} else
+		di_read_lock_child(dentry, !AuLock_IW);
+
+	ii_write_lock_child(inode);
+	if (file) {
+		bend = au_fbend(file);
+		for (bindex = au_fbstart(file); !err && bindex <= bend;
+		     bindex++) {
+			h_file = au_h_fptr(file, bindex);
+			if (!h_file || au_test_ro(sb, bindex, inode))
+				continue;
+
+			err = -EINVAL;
+			if (h_file->f_op && h_file->f_op->fsync) {
+				// todo: try do_fsync() in fs/sync.c
+#if 0 // debug
+				AuDebugOn(h_file->f_dentry->d_inode
+					  != au_h_iptr(inode, bindex));
+				au_hdir_lock(h_file->f_dentry->d_inode, inode,
+					     bindex);
+#else
+				mutex_lock(&h_file->f_mapping->host->i_mutex);
+#endif
+				err = h_file->f_op->fsync
+					(h_file, h_file->f_dentry, datasync);
+				//err = -1;
+				if (!err)
+					au_update_fuse_h_inode
+						(h_file->f_vfsmnt,
+						 h_file->f_dentry);
+				/*ignore*/
+#if 0 // debug
+				au_hdir_unlock(h_file->f_dentry->d_inode, inode,
+					       bindex);
+#else
+				mutex_unlock(&h_file->f_mapping->host->i_mutex);
+#endif
+			}
+		}
+	} else
+		err = fsync_dir(dentry, datasync);
+	au_cpup_attr_timesizes(inode);
+	ii_write_unlock(inode);
+	if (file)
+		fi_write_unlock(file);
+	else
+		di_read_unlock(dentry, !AuLock_IW);
+
+ out:
+	si_read_unlock(sb);
+	AuTraceErr(err);
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int aufs_readdir(struct file *file, void *dirent, filldir_t filldir)
+{
+	int err;
+	struct dentry *dentry;
+	struct inode *inode;
+	struct super_block *sb;
+
+	dentry = file->f_dentry;
+	LKTRTrace("%.*s, pos %Ld\n", AuDLNPair(dentry), file->f_pos);
+	inode = dentry->d_inode;
+	IMustLock(inode);
+
+	au_nfsd_lockdep_off();
+	sb = dentry->d_sb;
+	si_read_lock(sb, AuLock_FLUSH);
+	err = au_reval_and_lock_finfo(file, reopen_dir, /*wlock*/1,
+				      /*locked*/1);
+	if (unlikely(err))
+		goto out;
+
+	ii_write_lock_child(inode);
+	err = au_vdir_init(file);
+	if (unlikely(err)) {
+		ii_write_unlock(inode);
+		goto out_unlock;
+	}
+	//DbgVdir(au_fvdir_cache(file));// goto out_unlock;
+
+	/* nfsd filldir calls lookup_one_len(). */
+	ii_downgrade_lock(inode);
+	err = au_vdir_fill_de(file, dirent, filldir);
+	//DbgVdir(au_fvdir_cache(file));// goto out_unlock;
+
+	fsstack_copy_attr_atime(inode, au_h_iptr(inode, au_ibstart(inode)));
+	ii_read_unlock(inode);
+
+ out_unlock:
+	fi_write_unlock(file);
+ out:
+	si_read_unlock(sb);
+	au_nfsd_lockdep_on();
+#if 0 // debug
+	if (LktrCond)
+		igrab(inode);
+#endif
+	AuTraceErr(err);
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#define AuTestEmpty_WHONLY	1
+#define AuTestEmpty_DLGT	(1 << 1)
+#define AuTestEmpty_DIRPERM1	(1 << 2)
+#define AuTestEmpty_CALLED	(1 << 3)
+#define AuTestEmpty_SHWH	(1 << 4)
+#define au_ftest_testempty(flags, name)	((flags) & AuTestEmpty_##name)
+#define au_fset_testempty(flags, name)	{ (flags) |= AuTestEmpty_##name; }
+#define au_fclr_testempty(flags, name)	{ (flags) &= ~AuTestEmpty_##name; }
+#ifndef CONFIG_AUFS_DLGT
+#undef AuTestEmpty_DLGT
+#define AuTestEmpty_DLGT	0
+#undef AuTestEmpty_DIRPERM1
+#define AuTestEmpty_DIRPERM1	0
+#endif
+#ifndef CONFIG_AUFS_SHWH
+#undef AuTestEmpty_SHWH
+#define AuTestEmpty_SHWH	0
+#endif
+
+struct test_empty_arg {
+	struct au_nhash *whlist;
+	unsigned int flags;
+	int err;
+	aufs_bindex_t bindex;
+};
+
+static int test_empty_cb(void *__arg, const char *__name, int namelen,
+			 loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct test_empty_arg *arg = __arg;
+	char *name = (void *)__name;
+
+	LKTRTrace("%.*s\n", namelen, name);
+
+	arg->err = 0;
+	au_fset_testempty(arg->flags, CALLED);
+	//smp_mb();
+	if (name[0] == '.'
+	    && (namelen == 1 || (name[1] == '.' && namelen == 2)))
+		return 0; /* success */
+
+	if (namelen <= AUFS_WH_PFX_LEN
+	    || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
+		if (au_ftest_testempty(arg->flags, WHONLY)
+		    && !au_nhash_test_known_wh(arg->whlist, name, namelen))
+			arg->err = -ENOTEMPTY;
+		goto out;
+	}
+
+	name += AUFS_WH_PFX_LEN;
+	namelen -= AUFS_WH_PFX_LEN;
+	if (!au_nhash_test_known_wh(arg->whlist, name, namelen))
+		arg->err = au_nhash_append_wh
+			(arg->whlist, name, namelen, ino, d_type, arg->bindex,
+			 au_ftest_testempty(arg->flags, SHWH));
+
+ out:
+	//smp_mb();
+	AuTraceErr(arg->err);
+	return arg->err;
+}
+
+static int do_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
+{
+	int err, dlgt;
+	struct file *h_file;
+
+	LKTRTrace("%.*s, {%p, 0x%x, %d}\n",
+		  AuDLNPair(dentry), arg->whlist, arg->flags, arg->bindex);
+
+	h_file = au_h_open(dentry, arg->bindex,
+			   O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_LARGEFILE,
+			   /*file*/NULL);
+	err = PTR_ERR(h_file);
+	if (IS_ERR(h_file))
+		goto out;
+	err = 0;
+	if (unlikely(au_opt_test(au_mntflags(dentry->d_sb), UDBA_INOTIFY)
+		     && !h_file->f_dentry->d_inode->i_nlink))
+		goto out_put;
+
+	dlgt = au_ftest_testempty(arg->flags, DLGT);
+	//h_file->f_pos = 0;
+	do {
+		arg->err = 0;
+		au_fclr_testempty(arg->flags, CALLED);
+		//smp_mb();
+		err = vfsub_readdir(h_file, test_empty_cb, arg, dlgt);
+		if (err >= 0)
+			err = arg->err;
+	} while (!err && au_ftest_testempty(arg->flags, CALLED));
+
+ out_put:
+	fput(h_file);
+	au_sbr_put(dentry->d_sb, arg->bindex);
+ out:
+	AuTraceErr(err);
+	return err;
+}
+
+struct do_test_empty_args {
+	int *errp;
+	struct dentry *dentry;
+	struct test_empty_arg *arg;
+};
+
+static void call_do_test_empty(void *args)
+{
+	struct do_test_empty_args *a = args;
+	*a->errp = do_test_empty(a->dentry, a->arg);
+}
+
+static int sio_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
+{
+	int err, wkq_err;
+	struct dentry *h_dentry;
+	struct inode *h_inode;
+
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	h_dentry = au_h_dptr(dentry, arg->bindex);
+	AuDebugOn(!h_dentry);
+	h_inode = h_dentry->d_inode;
+	AuDebugOn(!h_inode || !S_ISDIR(h_inode->i_mode));
+
+	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
+	err = au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_READ,
+				 au_opt_test_dlgt(au_mntflags(dentry->d_sb)));
+	mutex_unlock(&h_inode->i_mutex);
+	if (!err)
+		err = do_test_empty(dentry, arg);
+	else {
+		struct do_test_empty_args args = {
+			.errp	= &err,
+			.dentry	= dentry,
+			.arg	= arg
+		};
+		unsigned int flags = arg->flags;
+		au_fclr_testempty(arg->flags, DLGT);
+		au_fclr_testempty(arg->flags, DIRPERM1);
+		wkq_err = au_wkq_wait(call_do_test_empty, &args, /*dlgt*/0);
+		if (unlikely(wkq_err))
+			err = wkq_err;
+		arg->flags = flags;
+	}
+
+	AuTraceErr(err);
+	return err;
+}
+
+int au_test_empty_lower(struct dentry *dentry)
+{
+	int err;
+	struct inode *inode;
+	struct test_empty_arg arg;
+	struct au_nhash *whlist;
+	aufs_bindex_t bindex, bstart, btail;
+	unsigned int mnt_flags;
+
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	inode = dentry->d_inode;
+	AuDebugOn(!inode || !S_ISDIR(inode->i_mode));
+
+	whlist = au_nhash_new(GFP_TEMPORARY);
+	err = PTR_ERR(whlist);
+	if (IS_ERR(whlist))
+		goto out;
+
+	bstart = au_dbstart(dentry);
+	mnt_flags = au_mntflags(dentry->d_sb);
+	arg.whlist = whlist;
+	arg.flags = 0;
+	if (unlikely(au_opt_test_dlgt(mnt_flags)))
+		au_fset_testempty(arg.flags, DLGT);
+	if (unlikely(au_opt_test(mnt_flags, SHWH)))
+		au_fset_testempty(arg.flags, SHWH);
+	arg.bindex = bstart;
+	err = do_test_empty(dentry, &arg);
+	if (unlikely(err))
+		goto out_whlist;
+
+	au_fset_testempty(arg.flags, WHONLY);
+	if (unlikely(au_opt_test_dirperm1(mnt_flags)))
+		au_fset_testempty(arg.flags, DIRPERM1);
+	btail = au_dbtaildir(dentry);
+	for (bindex = bstart + 1; !err && bindex <= btail; bindex++) {
+		struct dentry *h_dentry;
+		h_dentry = au_h_dptr(dentry, bindex);
+		if (h_dentry && h_dentry->d_inode) {
+			AuDebugOn(!S_ISDIR(h_dentry->d_inode->i_mode));
+			arg.bindex = bindex;
+			err = do_test_empty(dentry, &arg);
+		}
+	}
+
+ out_whlist:
+	au_nhash_del(whlist);
+ out:
+	AuTraceErr(err);
+	return err;
+}
+
+int au_test_empty(struct dentry *dentry, struct au_nhash *whlist)
+{
+	int err;
+	struct inode *inode;
+	struct test_empty_arg arg;
+	aufs_bindex_t bindex, btail;
+
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	inode = dentry->d_inode;
+	AuDebugOn(!inode || !S_ISDIR(inode->i_mode));
+
+	err = 0;
+	arg.whlist = whlist;
+	arg.flags = AuTestEmpty_WHONLY;
+	if (unlikely(au_opt_test(au_mntflags(dentry->d_sb), SHWH)))
+		au_fset_testempty(arg.flags, SHWH);
+	btail = au_dbtaildir(dentry);
+	for (bindex = au_dbstart(dentry); !err && bindex <= btail; bindex++) {
+		struct dentry *h_dentry;
+		h_dentry = au_h_dptr(dentry, bindex);
+		if (h_dentry && h_dentry->d_inode) {
+			AuDebugOn(!S_ISDIR(h_dentry->d_inode->i_mode));
+			arg.bindex = bindex;
+			err = sio_test_empty(dentry, &arg);
+		}
+	}
+
+	AuTraceErr(err);
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct file_operations aufs_dir_fop = {
+	.read		= generic_read_dir,
+	.readdir	= aufs_readdir,
+	.open		= aufs_open_dir,
+	.release	= aufs_release_dir,
+	.flush		= aufs_flush,
+	.fsync		= aufs_fsync_dir,
+};
-- 
1.4.4.4