commit f1dd4d6cbc6059c5606195a29c7117cfc92e9383
Author: Erez Zadok <[EMAIL PROTECTED]>
Date: Thu Jan 10 07:10:25 2008 -0500
Unionfs: implement lockdep classes
Lockdep fixes. Support locking order/classes (e.g., parent -> child ->
whiteout). Remove locking from create_parents: it's enough to just dget the
dentries in question. Move parent locking to from lookup_backend to caller,
unionfs_lookup.
Signed-off-by: Erez Zadok <[EMAIL PROTECTED]>
diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index 26573f3..55f016e 100644
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -378,7 +378,7 @@ int unionfs_file_revalidate(struct file *file, bool
willwrite)
int err = 0;
dentry = file->f_path.dentry;
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
sb = dentry->d_sb;
/*
@@ -601,7 +601,7 @@ int unionfs_open(struct inode *inode, struct file *file)
int bindex = 0, bstart = 0, bend = 0;
int size;
- unionfs_read_lock(inode->i_sb);
+ unionfs_read_lock(inode->i_sb, UNIONFS_SMUTEX_PARENT);
file->private_data =
kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL);
@@ -638,7 +638,7 @@ int unionfs_open(struct inode *inode, struct file *file)
err = -ESTALE;
goto out;
}
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
bstart = fbstart(file) = dbstart(dentry);
bend = fbend(file) = dbend(dentry);
@@ -701,7 +701,7 @@ int unionfs_file_release(struct inode *inode, struct file
*file)
int bindex, bstart, bend;
int fgen, err = 0;
- unionfs_read_lock(sb);
+ unionfs_read_lock(sb, UNIONFS_SMUTEX_PARENT);
/*
* 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
@@ -719,7 +719,7 @@ int unionfs_file_release(struct inode *inode, struct file
*file)
bstart = fbstart(file);
bend = fbend(file);
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
for (bindex = bstart; bindex <= bend; bindex++) {
lower_file = unionfs_lower_file_idx(file, bindex);
@@ -788,7 +788,7 @@ static int unionfs_ioctl_queryfile(struct file *file,
unsigned int cmd,
struct vfsmount *mnt;
dentry = file->f_path.dentry;
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
orig_bstart = dbstart(dentry);
orig_bend = dbend(dentry);
err = unionfs_partial_lookup(dentry);
@@ -838,7 +838,7 @@ long unionfs_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
long err;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, true);
if (unlikely(err))
@@ -877,7 +877,7 @@ int unionfs_flush(struct file *file, fl_owner_t id)
struct dentry *dentry = file->f_path.dentry;
int bindex, bstart, bend;
- unionfs_read_lock(dentry->d_sb);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, true);
if (unlikely(err))
diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index 33c2d33..3d21157 100644
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -723,7 +723,7 @@ struct dentry *create_parents(struct inode *dir, struct
dentry *dentry,
/* find the parent directory dentry in unionfs */
parent_dentry = child_dentry->d_parent;
- unionfs_lock_dentry(parent_dentry);
+ dget(parent_dentry);
/* find out the lower_parent_dentry in the given branch */
lower_parent_dentry =
@@ -758,7 +758,7 @@ struct dentry *create_parents(struct inode *dir, struct
dentry *dentry,
begin:
/* get lower parent dir in the current branch */
lower_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex);
- unionfs_unlock_dentry(parent_dentry);
+ dput(parent_dentry);
/* init the values to lookup */
childname = child_dentry->d_name.name;
@@ -849,7 +849,7 @@ out:
/* cleanup any leftover locks from the do/while loop above */
if (IS_ERR(lower_dentry))
while (count)
- unionfs_unlock_dentry(path[count--]);
+ dput(path[count--]);
kfree(path);
return lower_dentry;
}
diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c
index 03f2cb8..b312063 100644
--- a/fs/unionfs/dentry.c
+++ b/fs/unionfs/dentry.c
@@ -369,7 +369,7 @@ bool __unionfs_d_revalidate_chain(struct dentry *dentry,
struct nameidata *nd,
* to child order.
*/
for (i = 0; i < chain_len; i++) {
- unionfs_lock_dentry(chain[i]);
+ unionfs_lock_dentry(chain[i], UNIONFS_DMUTEX_REVAL+i);
saved_bstart = dbstart(chain[i]);
saved_bend = dbend(chain[i]);
sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation);
@@ -443,9 +443,9 @@ static int unionfs_d_revalidate(struct dentry *dentry,
struct nameidata *nd)
{
int err;
- unionfs_read_lock(dentry->d_sb);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
err = __unionfs_d_revalidate_chain(dentry, nd, false);
if (likely(err > 0)) { /* true==1: dentry is valid */
unionfs_check_dentry(dentry);
@@ -466,7 +466,7 @@ static void unionfs_d_release(struct dentry *dentry)
{
int bindex, bstart, bend;
- unionfs_read_lock(dentry->d_sb);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
unionfs_check_dentry(dentry);
/* this could be a negative dentry, so check first */
diff --git a/fs/unionfs/dirfops.c b/fs/unionfs/dirfops.c
index 2ac01d3..7f6ff5f 100644
--- a/fs/unionfs/dirfops.c
+++ b/fs/unionfs/dirfops.c
@@ -32,7 +32,7 @@ static int unionfs_readdir(struct file *file, void *dirent,
filldir_t filldir)
int namelen;
unsigned int d_type;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, false);
if (unlikely(err))
@@ -56,7 +56,7 @@ static int unionfs_readdir(struct file *file, void *dirent,
filldir_t filldir)
* odf cache dir calls partial lookup which expects a locked
* dentry
*/
- unionfs_lock_dentry(file->f_path.dentry);
+ unionfs_lock_dentry(file->f_path.dentry, UNIONFS_DMUTEX_CHILD);
err = odf_cache_dir(file->f_path.dentry, odf_cache,
&file->f_path.dentry->d_inode->i_mtime);
unionfs_unlock_dentry(file->f_path.dentry);
@@ -136,7 +136,7 @@ static loff_t unionfs_dir_llseek(struct file *file, loff_t
offset, int origin)
{
loff_t err;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, false);
if (unlikely(err))
diff --git a/fs/unionfs/export.c b/fs/unionfs/export.c
index c904753..fd82a33 100644
--- a/fs/unionfs/export.c
+++ b/fs/unionfs/export.c
@@ -253,7 +253,7 @@ static struct dentry *unionfs_export_iget(struct
super_block *sb,
}
if (!UNIONFS_D(result))
- err = new_dentry_private_data(result);
+ err = new_dentry_private_data(result, UNIONFS_DMUTEX_CHILD);
if (err) {
printk(KERN_INFO "unionfs_export_iget: Not enough memory to "
"allocate dentry's private data\n");
diff --git a/fs/unionfs/fanout.h b/fs/unionfs/fanout.h
index 2327238..590cd9e 100644
--- a/fs/unionfs/fanout.h
+++ b/fs/unionfs/fanout.h
@@ -277,10 +277,20 @@ static inline struct vfsmount *unionfs_lower_mnt(const
struct dentry *dent)
}
/* Macros for locking a dentry. */
-static inline void unionfs_lock_dentry(struct dentry *d)
+enum unionfs_dentry_lock_class {
+ UNIONFS_DMUTEX_NORMAL,
+ UNIONFS_DMUTEX_ROOT,
+ UNIONFS_DMUTEX_PARENT,
+ UNIONFS_DMUTEX_CHILD,
+ UNIONFS_DMUTEX_WHITEOUT,
+ UNIONFS_DMUTEX_REVAL, /* for file/dentry revalidate */
+};
+
+static inline void unionfs_lock_dentry(struct dentry *d,
+ unsigned int subclass)
{
BUG_ON(!d);
- mutex_lock(&UNIONFS_D(d)->lock);
+ mutex_lock_nested(&UNIONFS_D(d)->lock, subclass);
}
static inline void unionfs_unlock_dentry(struct dentry *d)
diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c
index 94784c3..b632042 100644
--- a/fs/unionfs/file.c
+++ b/fs/unionfs/file.c
@@ -30,7 +30,7 @@ static int unionfs_mmap(struct file *file, struct
vm_area_struct *vma)
bool willwrite;
struct file *lower_file;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
/* This might be deferred to mmap's writepage */
willwrite = ((vma->vm_flags | VM_SHARED | VM_WRITE) == vma->vm_flags);
@@ -80,7 +80,7 @@ int unionfs_fsync(struct file *file, struct dentry *dentry,
int datasync)
struct inode *lower_inode, *inode;
int err = -EINVAL;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, true);
if (unlikely(err))
goto out;
@@ -128,7 +128,7 @@ int unionfs_fasync(int fd, struct file *file, int flag)
struct inode *lower_inode, *inode;
int err = 0;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, true);
if (unlikely(err))
goto out;
diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index ac90756..12754a1 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -28,8 +28,8 @@ static int unionfs_create(struct inode *parent, struct dentry
*dentry,
int valid = 0;
struct nameidata lower_nd;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
valid = __unionfs_d_revalidate_chain(dentry, nd, false);
/*
@@ -144,7 +144,9 @@ static struct dentry *unionfs_lookup(struct inode *parent,
struct path path_save;
struct dentry *ret;
- unionfs_read_lock(dentry->d_sb);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ if (dentry != dentry->d_parent)
+ unionfs_lock_dentry(dentry->d_parent, UNIONFS_DMUTEX_PARENT);
/* save the dentry & vfsmnt from namei */
if (nd) {
@@ -176,6 +178,9 @@ static struct dentry *unionfs_lookup(struct inode *parent,
unionfs_check_nd(nd);
if (!IS_ERR(ret))
unionfs_unlock_dentry(dentry);
+
+ if (dentry != dentry->d_parent)
+ unionfs_unlock_dentry(dentry->d_parent);
unionfs_read_unlock(dentry->d_sb);
return ret;
@@ -189,7 +194,7 @@ static int unionfs_link(struct dentry *old_dentry, struct
inode *dir,
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_dir_dentry = NULL;
- unionfs_read_lock(old_dentry->d_sb);
+ unionfs_read_lock(old_dentry->d_sb, UNIONFS_SMUTEX_CHILD);
unionfs_double_lock_dentry(new_dentry, old_dentry);
if (unlikely(!__unionfs_d_revalidate_chain(old_dentry, NULL, false))) {
@@ -342,8 +347,8 @@ static int unionfs_symlink(struct inode *dir, struct dentry
*dentry,
umode_t mode;
int bstart;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(dentry->d_inode &&
!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
@@ -440,8 +445,8 @@ static int unionfs_mkdir(struct inode *parent, struct
dentry *dentry, int mode)
char *name = NULL;
int i, bend, bindex;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(dentry->d_inode &&
!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
@@ -550,8 +555,8 @@ static int unionfs_mknod(struct inode *dir, struct dentry
*dentry, int mode,
struct dentry *lower_parent_dentry = NULL;
int bstart;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(dentry->d_inode &&
!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
@@ -640,8 +645,8 @@ static int unionfs_readlink(struct dentry *dentry, char
__user *buf,
int err;
struct dentry *lower_dentry;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -718,9 +723,9 @@ out:
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
- unionfs_read_lock(dentry->d_sb);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
- unionfs_lock_dentry(dentry);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, nd, false)))
printk(KERN_ERR
"unionfs: put_link failed to revalidate dentry\n");
@@ -828,8 +833,8 @@ static int unionfs_setattr(struct dentry *dentry, struct
iattr *ia)
int bstart, bend, bindex;
loff_t size;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index 117adc7..b5a390f 100644
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -47,7 +47,6 @@ struct dentry *unionfs_lookup_backend(struct dentry *dentry,
struct dentry *first_dentry = NULL;
struct dentry *first_lower_dentry = NULL;
struct vfsmount *first_lower_mnt = NULL;
- int locked_parent = 0;
const char *name;
int namelen;
struct nameidata new_nd;
@@ -67,7 +66,7 @@ struct dentry *unionfs_lookup_backend(struct dentry *dentry,
case INTERPOSE_PARTIAL:
break;
case INTERPOSE_LOOKUP:
- err = new_dentry_private_data(dentry);
+ err = new_dentry_private_data(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(err))
goto out;
break;
@@ -84,10 +83,7 @@ struct dentry *unionfs_lookup_backend(struct dentry *dentry,
parent_dentry = dget_parent(dentry);
/* We never partial lookup the root directory. */
- if (parent_dentry != dentry) {
- unionfs_lock_dentry(parent_dentry);
- locked_parent = 1;
- } else {
+ if (parent_dentry == dentry) {
dput(parent_dentry);
parent_dentry = NULL;
goto out;
@@ -369,8 +365,6 @@ out:
UNIONFS_I(dentry->d_inode)->stale = 1;
}
}
- if (locked_parent)
- unionfs_unlock_dentry(parent_dentry);
dput(parent_dentry);
if (err && (lookupmode == INTERPOSE_LOOKUP))
unionfs_unlock_dentry(dentry);
@@ -384,6 +378,7 @@ out:
/*
* This is a utility function that fills in a unionfs dentry.
+ * Caller must lock this dentry with unionfs_lock_dentry.
*
* Returns: 0 (ok), or -ERRNO if an error occurred.
*/
@@ -485,7 +480,7 @@ static int realloc_dentry_private_data(struct dentry
*dentry)
}
/* allocate new dentry private data */
-int new_dentry_private_data(struct dentry *dentry)
+int new_dentry_private_data(struct dentry *dentry, int subclass)
{
struct unionfs_dentry_info *info = UNIONFS_D(dentry);
@@ -496,7 +491,7 @@ int new_dentry_private_data(struct dentry *dentry)
return -ENOMEM;
mutex_init(&info->lock);
- mutex_lock(&info->lock);
+ mutex_lock_nested(&info->lock, subclass);
info->lower_paths = NULL;
diff --git a/fs/unionfs/main.c b/fs/unionfs/main.c
index e0ebca8..beda8af 100644
--- a/fs/unionfs/main.c
+++ b/fs/unionfs/main.c
@@ -751,7 +751,7 @@ static int unionfs_read_super(struct super_block *sb, void
*raw_data,
/* link the upper and lower dentries */
sb->s_root->d_fsdata = NULL;
- err = new_dentry_private_data(sb->s_root);
+ err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT);
if (unlikely(err))
goto out_freedpd;
diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c
index aad2137..a0e654b 100644
--- a/fs/unionfs/mmap.c
+++ b/fs/unionfs/mmap.c
@@ -152,7 +152,7 @@ static int unionfs_readpage(struct file *file, struct page
*page)
char *page_data = NULL;
mode_t orig_mode;
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, false);
if (unlikely(err))
goto out;
@@ -245,7 +245,7 @@ static int unionfs_commit_write(struct file *file, struct
page *page,
BUG_ON(file == NULL);
- unionfs_read_lock(file->f_path.dentry->d_sb);
+ unionfs_read_lock(file->f_path.dentry->d_sb, UNIONFS_SMUTEX_PARENT);
err = unionfs_file_revalidate(file, true);
if (unlikely(err))
goto out;
diff --git a/fs/unionfs/odf.c b/fs/unionfs/odf.c
index 7873df7..c161ec8 100644
--- a/fs/unionfs/odf.c
+++ b/fs/unionfs/odf.c
@@ -898,7 +898,7 @@ skip:
lower_dentry = create_parents(dentry->d_parent->d_inode,
dentry, dentry->d_name.name,
branch_dst);
- unionfs_lock_dentry(dentry->d_parent);
+ unionfs_lock_dentry(dentry->d_parent, UNIONFS_DMUTEX_PARENT);
if (!lower_dentry || IS_ERR(lower_dentry)) {
if (IS_ERR(lower_dentry))
diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c
index e0eacf1..0b3d94d 100644
--- a/fs/unionfs/rename.c
+++ b/fs/unionfs/rename.c
@@ -348,7 +348,7 @@ int unionfs_rename(struct inode *old_dir, struct dentry
*old_dentry,
int err = 0;
struct dentry *lower;
- unionfs_read_lock(old_dentry->d_sb);
+ unionfs_read_lock(old_dentry->d_sb, UNIONFS_SMUTEX_CHILD);
unionfs_double_lock_dentry(old_dentry, new_dentry);
if (unlikely(!__unionfs_d_revalidate_chain(old_dentry, NULL, false))) {
diff --git a/fs/unionfs/subr.c b/fs/unionfs/subr.c
index f48c5ec..c864f66 100644
--- a/fs/unionfs/subr.c
+++ b/fs/unionfs/subr.c
@@ -30,7 +30,7 @@ int unionfs_refresh_lower_dentry(struct dentry *dentry, int
bindex)
verify_locked(dentry);
- unionfs_lock_dentry(dentry->d_parent);
+ unionfs_lock_dentry(dentry->d_parent, UNIONFS_DMUTEX_CHILD);
lower_parent = unionfs_lower_dentry_idx(dentry->d_parent, bindex);
unionfs_unlock_dentry(dentry->d_parent);
diff --git a/fs/unionfs/super.c b/fs/unionfs/super.c
index baa2e81..cb2618f 100644
--- a/fs/unionfs/super.c
+++ b/fs/unionfs/super.c
@@ -134,8 +134,8 @@ static int unionfs_statfs(struct dentry *dentry, struct
kstatfs *buf)
sb = dentry->d_sb;
- unionfs_read_lock(sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -948,7 +948,7 @@ static void unionfs_umount_begin(struct vfsmount *mnt, int
flags)
sb = mnt->mnt_sb;
- unionfs_read_lock(sb);
+ unionfs_read_lock(sb, UNIONFS_SMUTEX_CHILD);
bstart = sbstart(sb);
bend = sbend(sb);
@@ -973,9 +973,9 @@ static int unionfs_show_options(struct seq_file *m, struct
vfsmount *mnt)
int bindex, bstart, bend;
int perms;
- unionfs_read_lock(sb);
+ unionfs_read_lock(sb, UNIONFS_SMUTEX_CHILD);
- unionfs_lock_dentry(sb->s_root);
+ unionfs_lock_dentry(sb->s_root, UNIONFS_DMUTEX_CHILD);
tmp_page = (char *) __get_free_page(GFP_KERNEL);
if (unlikely(!tmp_page)) {
diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index e862a29..cfdb36c 100644
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -267,12 +267,18 @@ extern struct filldir_node *find_filldir_node(
#define MAXRDCOOKIE (0xfff)
#define DIREOF (0xffffff)
-static inline void unionfs_read_lock(struct super_block *sb)
+/* Macros for locking a super_block. */
+enum unionfs_super_lock_class {
+ UNIONFS_SMUTEX_NORMAL,
+ UNIONFS_SMUTEX_PARENT, /* when locking on behalf of file */
+ UNIONFS_SMUTEX_CHILD, /* when locking on behalf of dentry */
+};
+static inline void unionfs_read_lock(struct super_block *sb, int subclass)
{
if (UNIONFS_SB(sb)->write_lock_owner &&
UNIONFS_SB(sb)->write_lock_owner == current->pid)
return;
- down_read(&UNIONFS_SB(sb)->rwsem);
+ down_read_nested(&UNIONFS_SB(sb)->rwsem, subclass);
}
static inline void unionfs_read_unlock(struct super_block *sb)
{
@@ -295,16 +301,17 @@ static inline void unionfs_write_unlock(struct
super_block *sb)
static inline void unionfs_double_lock_dentry(struct dentry *d1,
struct dentry *d2)
{
- if (d2 < d1) {
- struct dentry *tmp = d1;
- d1 = d2;
- d2 = tmp;
+ BUG_ON(d1 == d2);
+ if (d1 < d2) {
+ unionfs_lock_dentry(d1, UNIONFS_DMUTEX_PARENT);
+ unionfs_lock_dentry(d2, UNIONFS_DMUTEX_CHILD);
+ } else {
+ unionfs_lock_dentry(d2, UNIONFS_DMUTEX_PARENT);
+ unionfs_lock_dentry(d1, UNIONFS_DMUTEX_CHILD);
}
- unionfs_lock_dentry(d1);
- unionfs_lock_dentry(d2);
}
-extern int new_dentry_private_data(struct dentry *dentry);
+extern int new_dentry_private_data(struct dentry *dentry, int subclass);
extern void free_dentry_private_data(struct dentry *dentry);
extern void update_bstart(struct dentry *dentry);
extern int init_lower_nd(struct nameidata *nd, unsigned int flags);
@@ -477,15 +484,18 @@ static inline int is_robranch(const struct dentry *dentry)
extern int check_branch(struct nameidata *nd);
extern int parse_branch_mode(const char *name, int *perms);
-/*
- * These two functions are here because it is kind of daft to copy and paste
- * the contents of the two functions to 32+ places in unionfs
- */
+/* locking helpers */
static inline struct dentry *lock_parent(struct dentry *dentry)
{
struct dentry *dir = dget(dentry->d_parent);
+ mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
+ return dir;
+}
+static inline struct dentry *lock_parent_wh(struct dentry *dentry)
+{
+ struct dentry *dir = dget(dentry->d_parent);
- mutex_lock(&dir->d_inode->i_mutex);
+ mutex_lock_nested(&dir->d_inode->i_mutex, UNIONFS_DMUTEX_WHITEOUT);
return dir;
}
diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c
index b009711..f16d32c 100644
--- a/fs/unionfs/unlink.c
+++ b/fs/unionfs/unlink.c
@@ -102,8 +102,8 @@ int unionfs_unlink(struct inode *dir, struct dentry *dentry)
{
int err = 0;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -223,8 +223,8 @@ int unionfs_rmdir(struct inode *dir, struct dentry *dentry)
struct unionfs_dir_state *namelist = NULL;
int dstart, dend;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
dstart = dbstart(dentry);
dend = dbend(dentry);
diff --git a/fs/unionfs/xattr.c b/fs/unionfs/xattr.c
index 00c6d0d..8001c65 100644
--- a/fs/unionfs/xattr.c
+++ b/fs/unionfs/xattr.c
@@ -45,8 +45,8 @@ ssize_t unionfs_getxattr(struct dentry *dentry, const char
*name, void *value,
struct dentry *lower_dentry = NULL;
int err = -EOPNOTSUPP;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -74,8 +74,8 @@ int unionfs_setxattr(struct dentry *dentry, const char *name,
struct dentry *lower_dentry = NULL;
int err = -EOPNOTSUPP;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -103,8 +103,8 @@ int unionfs_removexattr(struct dentry *dentry, const char
*name)
struct dentry *lower_dentry = NULL;
int err = -EOPNOTSUPP;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
@@ -132,8 +132,8 @@ ssize_t unionfs_listxattr(struct dentry *dentry, char
*list, size_t size)
int err = -EOPNOTSUPP;
char *encoded_list = NULL;
- unionfs_read_lock(dentry->d_sb);
- unionfs_lock_dentry(dentry);
+ unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
+ unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) {
err = -ESTALE;
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