commit b736a6881f199d38364624cb1283dce5ce70144c
Author: Yiannis Pericleous <[EMAIL PROTECTED]>
Date: Sat May 19 16:41:10 2007 -0400
Verify and maintain fanout invariants.
This somewhat long patch calls various invariant-checking (debugging)
functions in all places where the fanout invariants should hold. The three
invariant-checking functions, __unionfs_check_{inode,dentry,file}, perform
exhaustive sanity checking on the fan-out of various Unionfs objects. We
check that no lower objects exist outside the start/end branch range; that
all objects within are non-NULL (with some allowed exceptions); that for
every lower file there's a lower dentry+inode; that the start/end ranges
match for all corresponding lower objects; that open files/symlinks have
only one lower objects, but directories can have several; and more.
The rest of this patch actually fixes many places where these invariants did
not hold, which could lead to bugs or corruptions under heavy loads,
multi-threaded workloads, dynamic branch-management, and mmap operations.
Most of the bugs related to actions involving copyups and whiteouts. With
these fixes, the entire Unionfs regression suite passes without a single
invariant violated.
Conflicts:
fs/unionfs/commonfops.c
fs/unionfs/file.c
fs/unionfs/inode.c
fs/unionfs/unlink.c
diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index
a306f1e0a157a4ea84336be2025e3a3d5f8221f5..919378ad9d3a56c3129f008995a629acc8fe3997
100644
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -78,11 +78,18 @@ static int copyup_deleted_file(struct fi
/* bring it to the same state as an unlinked file */
hidden_dentry = unionfs_lower_dentry_idx(dentry, dbstart(dentry));
+ if (!unionfs_lower_inode_idx(dentry->d_inode, bindex)) {
+ atomic_inc(&hidden_dentry->d_inode->i_count);
+ unionfs_set_lower_inode_idx(dentry->d_inode, bindex,
+ hidden_dentry->d_inode);
+ }
hidden_dir_dentry = lock_parent(hidden_dentry);
err = vfs_unlink(hidden_dir_dentry->d_inode, hidden_dentry);
unlock_dir(hidden_dir_dentry);
out:
+ if (!err)
+ unionfs_check_dentry(dentry);
return err;
}
@@ -322,6 +329,8 @@ static int do_delayed_copyup(struct file
BUG_ON(!S_ISREG(file->f_dentry->d_inode->i_mode));
+ unionfs_check_file(file);
+ unionfs_check_dentry(dentry);
for (bindex = bstart - 1; bindex >= 0; bindex--) {
if (!d_deleted(file->f_dentry))
err = copyup_file(parent_inode, file, bstart,
@@ -343,9 +352,25 @@ static int do_delayed_copyup(struct file
fput(unionfs_lower_file_idx(file, bindex));
unionfs_set_lower_file_idx(file, bindex, NULL);
}
+ if (unionfs_lower_mnt_idx(dentry, bindex)) {
+ unionfs_mntput(dentry, bindex);
+ unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
+ }
+ if (unionfs_lower_dentry_idx(dentry, bindex)) {
+ BUG_ON(!dentry->d_inode);
+ iput(unionfs_lower_inode_idx(dentry->d_inode,
bindex));
+ unionfs_set_lower_inode_idx(dentry->d_inode,
bindex, NULL);
+ dput(unionfs_lower_dentry_idx(dentry, bindex));
+ unionfs_set_lower_dentry_idx(dentry, bindex,
NULL);
+ }
}
- fbend(file) = bend;
+ /* for reg file, we only open it "once" */
+ fbend(file) = fbstart(file);
+ set_dbend(dentry, dbstart(dentry));
+ ibend(dentry->d_inode) = ibstart(dentry->d_inode);
}
+ unionfs_check_file(file);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -439,6 +464,8 @@ out:
kfree(UNIONFS_F(file)->saved_branch_ids);
}
out_nofree:
+ if (!err)
+ unionfs_check_file(file);
unionfs_unlock_dentry(dentry);
return err;
}
@@ -633,6 +660,8 @@ out:
}
out_nofree:
unionfs_read_unlock(inode->i_sb);
+ unionfs_check_inode(inode);
+ unionfs_check_file(file);
return err;
}
@@ -640,19 +669,21 @@ out_nofree:
int unionfs_file_release(struct inode *inode, struct file *file)
{
struct file *hidden_file = NULL;
- struct unionfs_file_info *fileinfo;
- struct unionfs_inode_info *inodeinfo;
+ struct unionfs_file_info *fileinfo = UNIONFS_F(file);
+ struct unionfs_inode_info *inodeinfo = UNIONFS_I(inode);
struct super_block *sb = inode->i_sb;
int bindex, bstart, bend;
int fgen, err = 0;
+ unionfs_check_file(file);
unionfs_read_lock(sb);
+ /*
+ * Yes, we have to revalidate this file even if it's being released.
+ * This is important for open-but-unlinked files, as well as mmap
+ * support.
+ */
if ((err = unionfs_file_revalidate(file, 1)))
goto out;
- fileinfo = UNIONFS_F(file);
- BUG_ON(file->f_dentry->d_inode != inode);
- inodeinfo = UNIONFS_I(inode);
-
/* fput all the hidden files */
fgen = atomic_read(&fileinfo->generation);
bstart = fbstart(file);
@@ -776,6 +807,7 @@ long unionfs_ioctl(struct file *file, un
}
out:
+ unionfs_check_file(file);
return err;
}
@@ -790,6 +822,7 @@ int unionfs_flush(struct file *file, fl_
if ((err = unionfs_file_revalidate(file, 1)))
goto out;
+ unionfs_check_file(file);
if (!atomic_dec_and_test(&UNIONFS_I(dentry->d_inode)->totalopens))
goto out;
@@ -821,5 +854,6 @@ out_lock:
unionfs_unlock_dentry(dentry);
out:
unionfs_read_unlock(file->f_dentry->d_sb);
+ unionfs_check_file(file);
return err;
}
diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index
02aa62aac7606ceb0ebb0be6c81b5327f874ed7e..e93a799aa32fee554743bcdde7c1593649886f99
100644
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -489,6 +489,25 @@ out_free:
dput(old_hidden_dentry);
kfree(symbuf);
+ if (err)
+ goto out;
+ if (!S_ISDIR(dentry->d_inode->i_mode)) {
+ unionfs_purge_extras(dentry);
+ if (!unionfs_lower_inode(dentry->d_inode)) {
+ /*
+ * If we got here, then we copied up to an
+ * unlinked-open file, whose name is .unionfsXXXXX.
+ */
+ struct inode *inode = new_hidden_dentry->d_inode;
+ atomic_inc(&inode->i_count);
+ unionfs_set_lower_inode_idx(dentry->d_inode,
+ ibstart(dentry->d_inode),
+ inode);
+ }
+ }
+ unionfs_inherit_mnt(dentry);
+ unionfs_check_inode(dir);
+ unionfs_check_dentry(dentry);
out:
return err;
}
diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c
index
d1ee7921112f9b0c741fab5bb35a3c6bf715e2c7..1653267c1d5a5fa94861e633237f1954bcfecae8
100644
--- a/fs/unionfs/dentry.c
+++ b/fs/unionfs/dentry.c
@@ -289,9 +289,11 @@ static int unionfs_d_revalidate(struct d
{
int err;
+ unionfs_check_dentry(dentry);
unionfs_lock_dentry(dentry);
err = __unionfs_d_revalidate_chain(dentry, nd);
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -304,6 +306,7 @@ static void unionfs_d_release(struct den
{
int bindex, bstart, bend;
+ unionfs_check_dentry(dentry);
/* this could be a negative dentry, so check first */
if (!UNIONFS_D(dentry)) {
printk(KERN_DEBUG "unionfs: dentry without private data: %.*s",
diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c
index
9f61ded8cc4dd4c69539e10d1c82c89b8894ac45..5e34f6e2024625d47dd0c7eb539f8fc99edd98dd
100644
--- a/fs/unionfs/file.c
+++ b/fs/unionfs/file.c
@@ -39,6 +39,7 @@ static ssize_t unionfs_read(struct file
out:
unionfs_read_unlock(file->f_dentry->d_sb);
+ unionfs_check_file(file);
return err;
}
@@ -56,6 +57,9 @@ static ssize_t unionfs_aio_read(struct k
touch_atime(unionfs_lower_mnt(iocb->ki_filp->f_path.dentry),
unionfs_lower_dentry(iocb->ki_filp->f_path.dentry));
+out:
+ unionfs_read_unlock(file->f_dentry->d_sb);
+ unionfs_check_file(file);
return err;
}
static ssize_t unionfs_write(struct file * file, const char __user * buf,
@@ -71,6 +75,7 @@ static ssize_t unionfs_write(struct file
out:
unionfs_read_unlock(file->f_dentry->d_sb);
+ unionfs_check_file(file);
return err;
}
@@ -97,6 +102,7 @@ static int unionfs_mmap(struct file *fil
out:
unionfs_read_unlock(file->f_dentry->d_sb);
+ unionfs_check_file(file);
return err;
}
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index
8f9d38bb6971b4715889a6097abb8678e1e5944a..4e33e74eabf8716a6b443168cf76410a086fb5ed
100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -111,8 +111,14 @@ static int unionfs_create(struct inode *
out:
+ if (!err)
+ unionfs_inherit_mnt(dentry);
unionfs_unlock_dentry(dentry);
unionfs_read_unlock(dentry->d_sb);
+
+ unionfs_check_inode(parent);
+ unionfs_check_dentry(dentry->d_parent);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -137,7 +143,11 @@ static struct dentry *unionfs_lookup(str
nd->dentry = path_save.dentry;
nd->mnt = path_save.mnt;
}
+ if (!IS_ERR(ret))
+ unionfs_inherit_mnt(dentry);
+ unionfs_check_inode(parent);
+ unionfs_check_dentry(dentry);
return ret;
}
@@ -253,9 +263,15 @@ out:
if (!new_dentry->d_inode)
d_drop(new_dentry);
+ if (!err)
+ unionfs_inherit_mnt(new_dentry);
+
unionfs_unlock_dentry(new_dentry);
unionfs_unlock_dentry(old_dentry);
+ unionfs_check_inode(dir);
+ unionfs_check_dentry(new_dentry);
+ unionfs_check_dentry(old_dentry);
return err;
}
@@ -334,7 +350,12 @@ static int unionfs_symlink(struct inode
d_drop(dentry);
out:
+ if (!err)
+ unionfs_inherit_mnt(dentry);
unionfs_unlock_dentry(dentry);
+
+ unionfs_check_inode(dir);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -428,6 +449,8 @@ out:
kfree(name);
unionfs_unlock_dentry(dentry);
+ unionfs_check_inode(parent);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -500,7 +523,12 @@ out:
if (!dentry->d_inode)
d_drop(dentry);
+ if (!err)
+ unionfs_inherit_mnt(dentry);
unionfs_unlock_dentry(dentry);
+
+ unionfs_check_inode(dir);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -529,6 +557,7 @@ static int unionfs_readlink(struct dentr
out:
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -563,12 +592,14 @@ static void *unionfs_follow_link(struct
err = 0;
out:
+ unionfs_check_dentry(dentry);
return ERR_PTR(err);
}
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
+ unionfs_check_dentry(dentry);
kfree(nd_get_link(nd));
}
@@ -692,6 +723,7 @@ static int unionfs_permission(struct ino
out:
unionfs_read_unlock(inode->i_sb);
+ unionfs_check_inode(inode);
return err;
}
@@ -766,9 +798,9 @@ static int unionfs_setattr(struct dentry
hidden_inode = unionfs_lower_inode(dentry->d_inode);
fsstack_copy_attr_all(inode, hidden_inode, unionfs_get_nlinks);
fsstack_copy_inode_size(inode, hidden_inode);
-
out:
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index
62731ca385cb5ca64d40623113ca57000836c277..4e106b65756e11107686a7e64b6dd5d2485e9d4c
100644
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -383,13 +383,42 @@ out:
if (err)
/* clear the new_dentry stuff created */
d_drop(new_dentry);
- else
+ else {
/*
* force re-lookup since the dir on ro branch is not renamed,
* and hidden dentries still indicate the un-renamed ones.
*/
if (S_ISDIR(old_dentry->d_inode->i_mode))
atomic_dec(&UNIONFS_D(old_dentry)->generation);
+ else
+ unionfs_purge_extras(old_dentry);
+ if (new_dentry->d_inode &&
+ !S_ISDIR(new_dentry->d_inode->i_mode)) {
+ unionfs_purge_extras(new_dentry);
+ unionfs_inherit_mnt(new_dentry);
+ if (!unionfs_lower_inode(new_dentry->d_inode)) {
+ /*
+ * If we get here, it means that no copyup
+ * was needed, and that a file by the old
+ * name already existing on the destination
+ * branch; that file got renamed earlier in
+ * this function, so all we need to do here
+ * is set the lower inode.
+ */
+ struct inode *inode;
+ inode =
unionfs_lower_inode(old_dentry->d_inode);
+ atomic_inc(&inode->i_count);
+ unionfs_set_lower_inode_idx(
+ new_dentry->d_inode,
+ dbstart(new_dentry), inode);
+ }
+
+ }
+ unionfs_check_inode(old_dir);
+ unionfs_check_inode(new_dir);
+ unionfs_check_dentry(old_dentry);
+ unionfs_check_dentry(new_dentry);
+ }
unionfs_unlock_dentry(new_dentry);
unionfs_unlock_dentry(old_dentry);
diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c
index
29987254ca49625185b42c53ab1af57c0257ebca..7a4ec0822f2a4ff2f4fa1fca25d9ea26f66bb2ee
100644
--- a/fs/unionfs/unlink.c
+++ b/fs/unionfs/unlink.c
@@ -98,6 +98,7 @@ int unionfs_unlink(struct inode *dir, st
BUG_ON(!is_valid_dentry(dentry));
+ unionfs_check_dentry(dentry);
unionfs_lock_dentry(dentry);
err = unionfs_do_unlink(dir, dentry);
@@ -110,8 +111,14 @@ int unionfs_unlink(struct inode *dir, st
*/
/* FIXME: what if this fails? */
err = odf_remove(dentry, ODF_RMV_NOTWH);
+ }
+ if (!err) {
+ if (!S_ISDIR(dentry->d_inode->i_mode))
+ unionfs_purge_extras(dentry);
+ unionfs_check_dentry(dentry);
d_drop(dentry);
}
+
unionfs_unlock_dentry(dentry);
return err;
}
@@ -192,6 +199,7 @@ int unionfs_rmdir(struct inode *dir, str
BUG_ON(!is_valid_dentry(dentry));
+ unionfs_check_dentry(dentry);
unionfs_lock_dentry(dentry);
/* check if this unionfs directory is empty or not */
diff --git a/fs/unionfs/xattr.c b/fs/unionfs/xattr.c
index
12d618bd8f498dc2e632a3891edad2f6cb833768..4cacead60c61a7d7053832068b231b5b386fdb9a
100644
--- a/fs/unionfs/xattr.c
+++ b/fs/unionfs/xattr.c
@@ -66,6 +66,7 @@ ssize_t unionfs_getxattr(struct dentry *
err = vfs_getxattr(hidden_dentry, (char*) name, value, size);
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -88,6 +89,7 @@ int unionfs_setxattr(struct dentry *dent
size, flags);
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -108,6 +110,7 @@ int unionfs_removexattr(struct dentry *d
err = vfs_removexattr(hidden_dentry, (char*) name);
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
@@ -131,5 +134,6 @@ ssize_t unionfs_listxattr(struct dentry
err = vfs_listxattr(hidden_dentry, encoded_list, size);
unionfs_unlock_dentry(dentry);
+ unionfs_check_dentry(dentry);
return err;
}
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