GIT: unionfs2-2.6.27.y: Unionfs: pass nameidata intent information to lower level file systems
Erez Zadok
ezk at fsl.cs.sunysb.edu
Thu Aug 12 23:16:50 EDT 2010
commit 6486f1063c052b39513fb98e60a18953aacf18db
Author: Erez_Zadok <ezk at cs.sunysb.edu>
Date: Mon Jul 23 03:13:01 2007 -0400
Unionfs: pass nameidata intent information to lower level file systems
As of 2.6.23-rc1, nfs2 and nfs3, like nfs4 before them, begin relying on the
struct nameidata and especially the intent information, which is passed to
vfs_create() and others. So, as of now, unionfs properly creates and passes
that intent data to the lower level file system. Currently supported are
LOOKUP_CREATE open intents. Others can be supported in the future
incrementally.
Signed-off-by: Erez Zadok <ezk at cs.sunysb.edu>
diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index eb5d5a0..868923a 100644
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -177,19 +177,26 @@ static int __copyup_ndentry(struct dentry *old_lower_dentry,
run_sioq(__unionfs_mknod, &args);
err = args.err;
} else if (S_ISREG(old_mode)) {
+ struct nameidata *nd = alloc_lower_nd(LOOKUP_CREATE);
+ if (!nd) {
+ err = -ENOMEM;
+ goto out;
+ }
+ args.create.nd = nd;
args.create.parent = new_lower_parent_dentry->d_inode;
args.create.dentry = new_lower_dentry;
args.create.mode = old_mode;
- args.create.nd = NULL;
run_sioq(__unionfs_create, &args);
err = args.err;
+ free_lower_nd(nd, err);
} else {
printk(KERN_ERR "unionfs: unknown inode type %d\n",
old_mode);
BUG();
}
+out:
return err;
}
diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index 2045a43..f21a9f3 100644
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -573,3 +573,65 @@ void update_bstart(struct dentry *dentry)
unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
}
}
+
+
+/*
+ * Allocate and fill in a nameidata structure (the intent part) we can pass
+ * to a lower file system. Returns NULL on error (only -ENOMEM possible),
+ * or a valid allocated nameidata structure. Inside that structure, this
+ * function may also return an allocated struct file (for open intents).
+ * The caller, when done with this nd, must kfree both the intent file and
+ * the entire nd.
+ */
+struct nameidata *alloc_lower_nd(unsigned int flags)
+{
+ struct nameidata *nd;
+#ifdef ALLOC_LOWER_ND_FILE
+ /*
+ * XXX: one day we may need to have the lower return an open file
+ * for us. It is not needed in 2.6.23-rc1 for nfs2/nfs3, but may
+ * very well be needed for nfs4.
+ */
+ struct file *file;
+#endif /* ALLOC_LOWER_ND_FILE */
+
+ nd = kzalloc(sizeof(struct nameidata), GFP_KERNEL);
+ if (!nd)
+ goto out;
+
+ switch (flags) {
+ case LOOKUP_CREATE:
+ nd->flags = LOOKUP_CREATE;
+ nd->intent.open.flags = FMODE_READ | FMODE_WRITE | O_CREAT;
+#ifdef ALLOC_LOWER_ND_FILE
+ file = kzalloc(sizeof(struct file), GFP_KERNEL);
+ if (!file) {
+ kfree(nd);
+ nd = NULL;
+ goto out;
+ }
+ nd->intent.open.file = file;
+#endif /* ALLOC_LOWER_ND_FILE */
+ break;
+ default:
+ /*
+ * We should never get here, for now.
+ * We can add new cases here later on.
+ */
+ BUG();
+ break;
+ }
+out:
+ return nd;
+}
+
+void free_lower_nd(struct nameidata *nd, int err)
+{
+ if (nd->intent.open.file) {
+ if (!err)
+ fput(nd->intent.open.file); /* XXX: open file not needed? */
+ kfree(nd->intent.open.file);
+ }
+ kfree(nd);
+}
+
diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index 1761f8b..d6b0215 100644
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -256,6 +256,7 @@ static int do_unionfs_rename(struct inode *old_dir,
*/
if ((old_bstart != old_bend) || (do_copyup != -1)) {
struct dentry *lower_parent;
+ struct nameidata *nd;
if (!wh_old || wh_old->d_inode || bwh_old < 0) {
printk(KERN_ERR "unionfs: rename error "
"(wh_old=%p/%p bwh_old=%d)\n", wh_old,
@@ -263,9 +264,14 @@ static int do_unionfs_rename(struct inode *old_dir,
err = -EIO;
goto out;
}
+ nd = alloc_lower_nd(LOOKUP_CREATE);
+ if (!nd) {
+ err = -ENOMEM;
+ goto out;
+ }
lower_parent = lock_parent(wh_old);
local_err = vfs_create(lower_parent->d_inode, wh_old, S_IRUGO,
- NULL);
+ nd);
unlock_dir(lower_parent);
if (!local_err)
set_dbopaque(old_dentry, bwh_old);
@@ -278,6 +284,7 @@ static int do_unionfs_rename(struct inode *old_dir,
"the source in rename!\n");
err = -EIO;
}
+ free_lower_nd(nd, local_err);
}
out:
diff --git a/fs/unionfs/subr.c b/fs/unionfs/subr.c
index 5db9e62..3b76737 100644
--- a/fs/unionfs/subr.c
+++ b/fs/unionfs/subr.c
@@ -29,6 +29,7 @@ int create_whiteout(struct dentry *dentry, int start)
struct dentry *lower_dir_dentry;
struct dentry *lower_dentry;
struct dentry *lower_wh_dentry;
+ struct nameidata *nd;
char *name = NULL;
int err = -EINVAL;
@@ -82,14 +83,20 @@ int create_whiteout(struct dentry *dentry, int start)
goto out;
}
+ nd = alloc_lower_nd(LOOKUP_CREATE);
+ if (!nd) {
+ err = -ENOMEM;
+ goto out;
+ }
lower_dir_dentry = lock_parent(lower_wh_dentry);
if (!(err = is_robranch_super(dentry->d_sb, bindex)))
err = vfs_create(lower_dir_dentry->d_inode,
lower_wh_dentry,
~current->fs->umask & S_IRWXUGO,
- NULL);
+ nd);
unlock_dir(lower_dir_dentry);
dput(lower_wh_dentry);
+ free_lower_nd(nd, err);
if (!err || !IS_COPYUP_ERR(err))
break;
@@ -151,6 +158,7 @@ int make_dir_opaque(struct dentry *dentry, int bindex)
int err = 0;
struct dentry *lower_dentry, *diropq;
struct inode *lower_dir;
+ struct nameidata *nd;
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
lower_dir = lower_dentry->d_inode;
@@ -165,10 +173,16 @@ int make_dir_opaque(struct dentry *dentry, int bindex)
goto out;
}
+ nd = alloc_lower_nd(LOOKUP_CREATE);
+ if (!nd) {
+ err = -ENOMEM;
+ goto out;
+ }
if (!diropq->d_inode)
- err = vfs_create(lower_dir, diropq, S_IRUGO, NULL);
+ err = vfs_create(lower_dir, diropq, S_IRUGO, nd);
if (!err)
set_dbopaque(dentry, bindex);
+ free_lower_nd(nd, err);
dput(diropq);
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index cd1f37c..00f2b36 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -252,6 +252,8 @@ extern int realloc_dentry_private_data(struct dentry *dentry);
extern int new_dentry_private_data(struct dentry *dentry);
extern void free_dentry_private_data(struct dentry *dentry);
extern void update_bstart(struct dentry *dentry);
+extern struct nameidata *alloc_lower_nd(unsigned int flags);
+extern void free_lower_nd(struct nameidata *nd, int err);
/*
* EXTERNALS:
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