Allow filesystem to initialize dentry (->d_fsdata to be explicit) at
allocation time.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
Documentation/filesystems/Locking | 2 ++
Documentation/filesystems/vfs.txt | 3 +++
fs/dcache.c | 11 +++++++++++
include/linux/dcache.h | 1 +
4 files changed, 17 insertions(+)
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 75eea7ce3d7c..6da7d7363709 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -15,6 +15,7 @@ prototypes:
int (*d_compare)(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
int (*d_delete)(struct dentry *);
+ int (*d_allocate)(struct dentry *);
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
@@ -28,6 +29,7 @@ d_weak_revalidate:no no yes no
d_hash no no no maybe
d_compare: yes no no maybe
d_delete: no yes no no
+d_allocate: no no yes no
d_release: no no yes no
d_prune: no yes no no
d_iput: no no yes no
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index c61a223ef3ff..4d8f1a5d8936 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -933,6 +933,7 @@ struct dentry_operations {
int (*d_compare)(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
int (*d_delete)(const struct dentry *);
+ int (*d_allocate)(struct dentry *);
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
@@ -1003,6 +1004,8 @@ struct dentry_operations {
always cache a reachable dentry. d_delete must be constant and
idempotent.
+ d_allocate: called when a dentry is really allocated
+
d_release: called when a dentry is really deallocated
d_iput: called when a dentry loses its inode (just prior to its
diff --git a/fs/dcache.c b/fs/dcache.c
index 817c243c1ff1..dc573af50edc 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1559,6 +1559,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
{
struct dentry *dentry;
char *dname;
+ int err;
dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
if (!dentry)
@@ -1617,6 +1618,16 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
INIT_LIST_HEAD(&dentry->d_child);
d_set_d_op(dentry, dentry->d_sb->s_d_op);
+ if (dentry->d_op && dentry->d_op->d_allocate) {
+ err = dentry->d_op->d_allocate(dentry);
+ if (err) {
+ if (dname_external(dentry))
+ kfree(external_name(dentry));
+ kmem_cache_free(dentry_cache, dentry);
+ return NULL;
+ }
+ }
+
this_cpu_inc(nr_dentry);
return dentry;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index f28100f6b556..a2f01284b277 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -133,6 +133,7 @@ struct dentry_operations {
int (*d_compare)(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
int (*d_delete)(const struct dentry *);
+ int (*d_allocate)(struct dentry *);
void (*d_release)(struct dentry *);
void (*d_prune)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
--
2.5.5
--
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