Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <[email protected]>
---
Documentation/filesystems/Locking | 5 +++--
Documentation/filesystems/porting | 7 +++++++
Documentation/filesystems/vfs.txt | 8 ++++++--
fs/adfs/dir.c | 3 ++-
fs/affs/namei.c | 20 ++++++++++++--------
fs/cifs/dir.c | 5 +++--
fs/cifs/readdir.c | 2 +-
fs/dcache.c | 2 +-
fs/ecryptfs/inode.c | 4 ++--
fs/fat/namei_msdos.c | 3 ++-
fs/fat/namei_vfat.c | 8 +++++---
fs/gfs2/dentry.c | 3 ++-
fs/hfs/hfs_fs.h | 3 ++-
fs/hfs/string.c | 3 ++-
fs/hfsplus/hfsplus_fs.h | 3 ++-
fs/hfsplus/unicode.c | 3 ++-
fs/hpfs/dentry.c | 3 ++-
fs/isofs/inode.c | 28 ++++++++++++++++++----------
fs/jfs/namei.c | 3 ++-
fs/namei.c | 5 +++--
fs/ncpfs/dir.c | 10 +++++-----
fs/sysv/namei.c | 3 ++-
include/linux/dcache.h | 3 ++-
23 files changed, 88 insertions(+), 49 deletions(-)
Index: linux-2.6/fs/adfs/dir.c
===================================================================
--- linux-2.6.orig/fs/adfs/dir.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/adfs/dir.c 2010-11-17 00:52:37.000000000 +1100
@@ -201,7 +201,8 @@ const struct file_operations adfs_dir_op
};
static int
-adfs_hash(struct dentry *parent, struct qstr *qstr)
+adfs_hash(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr)
{
const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
const unsigned char *name;
Index: linux-2.6/fs/affs/namei.c
===================================================================
--- linux-2.6.orig/fs/affs/namei.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/affs/namei.c 2010-11-17 00:52:37.000000000 +1100
@@ -13,12 +13,14 @@
typedef int (*toupper_t)(int);
static int affs_toupper(int ch);
-static int affs_hash_dentry(struct dentry *, struct qstr *);
+static int affs_hash_dentry(const struct dentry *,
+ const struct inode *, struct qstr *);
static int affs_compare_dentry(const struct dentry *parent,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name);
static int affs_intl_toupper(int ch);
-static int affs_intl_hash_dentry(struct dentry *, struct qstr *);
+static int affs_intl_hash_dentry(const struct dentry *,
+ const struct inode *, struct qstr *);
static int affs_intl_compare_dentry(const struct dentry *parent,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name);
@@ -62,13 +64,13 @@ affs_get_toupper(struct super_block *sb)
* Note: the dentry argument is the parent dentry.
*/
static inline int
-__affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
+__affs_hash_dentry(struct qstr *qstr, toupper_t toupper)
{
const u8 *name = qstr->name;
unsigned long hash;
int i;
- i = affs_check_name(qstr->name,qstr->len);
+ i = affs_check_name(qstr->name, qstr->len);
if (i)
return i;
@@ -82,14 +84,16 @@ __affs_hash_dentry(struct dentry *dentry
}
static int
-affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- return __affs_hash_dentry(dentry, qstr, affs_toupper);
+ return __affs_hash_dentry(qstr, affs_toupper);
}
static int
-affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+affs_intl_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
+ return __affs_hash_dentry(qstr, affs_intl_toupper);
}
static inline int __affs_compare_dentry(unsigned int len,
Index: linux-2.6/fs/cifs/dir.c
===================================================================
--- linux-2.6.orig/fs/cifs/dir.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/cifs/dir.c 2010-11-17 00:52:37.000000000 +1100
@@ -700,9 +700,10 @@ const struct dentry_operations cifs_dent
/* d_delete: cifs_d_delete, */ /* not needed except for debugging */
};
-static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
+static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *q)
{
- struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
+ struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
unsigned long hash;
int i;
Index: linux-2.6/fs/fat/namei_msdos.c
===================================================================
--- linux-2.6.orig/fs/fat/namei_msdos.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/fat/namei_msdos.c 2010-11-17 00:52:37.000000000 +1100
@@ -148,7 +148,8 @@ static int msdos_find(struct inode *dir,
* that the existing dentry can be used. The msdos fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
+static int msdos_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
unsigned char msdos_name[MSDOS_NAME];
Index: linux-2.6/fs/fat/namei_vfat.c
===================================================================
--- linux-2.6.orig/fs/fat/namei_vfat.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/fat/namei_vfat.c 2010-11-17 00:52:37.000000000 +1100
@@ -103,7 +103,8 @@ static unsigned int vfat_striptail_len(c
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
return 0;
@@ -115,9 +116,10 @@ static int vfat_hash(struct dentry *dent
* that the existing dentry can be used. The vfat fs routines will
* return ENOENT or EINVAL as appropriate.
*/
-static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
+static int vfat_hashi(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
- struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+ struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io;
const unsigned char *name;
unsigned int len;
unsigned long hash;
Index: linux-2.6/fs/gfs2/dentry.c
===================================================================
--- linux-2.6.orig/fs/gfs2/dentry.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/gfs2/dentry.c 2010-11-17 00:52:37.000000000 +1100
@@ -100,7 +100,8 @@ static int gfs2_drevalidate(struct dentr
return 0;
}
-static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
+static int gfs2_dhash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str)
{
str->hash = gfs2_disk_hash(str->name, str->len);
return 0;
Index: linux-2.6/fs/hfs/hfs_fs.h
===================================================================
--- linux-2.6.orig/fs/hfs/hfs_fs.h 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/hfs/hfs_fs.h 2010-11-17 00:52:37.000000000 +1100
@@ -213,7 +213,8 @@ extern int hfs_part_find(struct super_bl
/* string.c */
extern const struct dentry_operations hfs_dentry_operations;
-extern int hfs_hash_dentry(struct dentry *, struct qstr *);
+extern int hfs_hash_dentry(const struct dentry *, const struct inode *,
+ struct qstr *);
extern int hfs_strcmp(const unsigned char *, unsigned int,
const unsigned char *, unsigned int);
extern int hfs_compare_dentry(const struct dentry *parent,
Index: linux-2.6/fs/hfs/string.c
===================================================================
--- linux-2.6.orig/fs/hfs/string.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/hfs/string.c 2010-11-17 00:52:37.000000000 +1100
@@ -51,7 +51,8 @@ static unsigned char caseorder[256] = {
/*
* Hash a string to an integer in a case-independent way
*/
-int hfs_hash_dentry(struct dentry *dentry, struct qstr *this)
+int hfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *this)
{
const unsigned char *name = this->name;
unsigned int hash, len = this->len;
Index: linux-2.6/fs/hfsplus/hfsplus_fs.h
===================================================================
--- linux-2.6.orig/fs/hfsplus/hfsplus_fs.h 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/hfsplus/hfsplus_fs.h 2010-11-17 00:52:37.000000000 +1100
@@ -379,7 +379,8 @@ int hfsplus_strcasecmp(const struct hfsp
int hfsplus_strcmp(const struct hfsplus_unistr *, const struct hfsplus_unistr *);
int hfsplus_uni2asc(struct super_block *, const struct hfsplus_unistr *, char *, int *);
int hfsplus_asc2uni(struct super_block *, struct hfsplus_unistr *, const char *, int);
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str);
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str);
int hfsplus_compare_dentry(const struct dentry *parent,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name);
Index: linux-2.6/fs/hfsplus/unicode.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/unicode.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/hfsplus/unicode.c 2010-11-17 00:52:37.000000000 +1100
@@ -320,7 +320,8 @@ int hfsplus_asc2uni(struct super_block *
* Composed unicode characters are decomposed and case-folding is performed
* if the appropriate bits are (un)set on the superblock.
*/
-int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str)
+int hfsplus_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *str)
{
struct super_block *sb = dentry->d_sb;
const char *astr;
Index: linux-2.6/fs/hpfs/dentry.c
===================================================================
--- linux-2.6.orig/fs/hpfs/dentry.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/hpfs/dentry.c 2010-11-17 00:52:37.000000000 +1100
@@ -12,7 +12,8 @@
* Note: the dentry argument is the parent dentry.
*/
-static int hpfs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
+static int hpfs_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
unsigned long hash;
int i;
Index: linux-2.6/fs/isofs/inode.c
===================================================================
--- linux-2.6.orig/fs/isofs/inode.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/isofs/inode.c 2010-11-17 00:52:37.000000000 +1100
@@ -26,8 +26,10 @@
#define BEQUIET
-static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash(struct dentry *parent, struct qstr *qstr);
+static int isofs_hashi(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_hash(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
static int isofs_dentry_cmpi(const struct dentry *parent,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name);
@@ -36,8 +38,10 @@ static int isofs_dentry_cmp(const struct
unsigned int len, const char *str, const struct qstr *name);
#ifdef CONFIG_JOLIET
-static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
-static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
+static int isofs_hashi_ms(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
+static int isofs_hash_ms(const struct dentry *parent, const struct inode *inode,
+ struct qstr *qstr);
static int isofs_dentry_cmpi_ms(const struct dentry *parent,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name);
@@ -168,7 +172,7 @@ struct iso9660_options{
* Compute the hash for the isofs name corresponding to the dentry.
*/
static int
-isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hash_common(const struct dentry *dentry, struct qstr *qstr, int ms)
{
const char *name;
int len;
@@ -189,7 +193,7 @@ isofs_hash_common(struct dentry *dentry,
* Compute the hash for the isofs name corresponding to the dentry.
*/
static int
-isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
+isofs_hashi_common(const struct dentry *dentry, struct qstr *qstr, int ms)
{
const char *name;
int len;
@@ -244,13 +248,15 @@ static int isofs_dentry_cmp_common(
}
static int
-isofs_hash(struct dentry *dentry, struct qstr *qstr)
+isofs_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hash_common(dentry, qstr, 0);
}
static int
-isofs_hashi(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hashi_common(dentry, qstr, 0);
}
@@ -273,13 +279,15 @@ isofs_dentry_cmpi(const struct dentry *p
#ifdef CONFIG_JOLIET
static int
-isofs_hash_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hash_ms(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hash_common(dentry, qstr, 1);
}
static int
-isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr)
+isofs_hashi_ms(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
return isofs_hashi_common(dentry, qstr, 1);
}
Index: linux-2.6/fs/jfs/namei.c
===================================================================
--- linux-2.6.orig/fs/jfs/namei.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/jfs/namei.c 2010-11-17 00:52:37.000000000 +1100
@@ -1574,7 +1574,8 @@ const struct file_operations jfs_dir_ope
.llseek = generic_file_llseek,
};
-static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
+static int jfs_ci_hash(const struct dentry *dir, const struct inode *inode,
+ struct qstr *this)
{
unsigned long hash;
int i;
Index: linux-2.6/fs/ncpfs/dir.c
===================================================================
--- linux-2.6.orig/fs/ncpfs/dir.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/ncpfs/dir.c 2010-11-17 01:05:45.000000000 +1100
@@ -75,7 +75,8 @@ const struct inode_operations ncp_dir_in
* Dentry operations routines
*/
static int ncp_lookup_validate(struct dentry *, struct nameidata *);
-static int ncp_hash_dentry(struct dentry *, struct qstr *);
+static int ncp_hash_dentry(const struct dentry *, const struct inode *,
+ struct qstr *);
static int ncp_compare_dentry(const struct dentry *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@@ -130,10 +131,9 @@ static inline int ncp_case_sensitive(con
* is case-sensitive.
*/
static int
-ncp_hash_dentry(struct dentry *dentry, struct qstr *this)
+ncp_hash_dentry(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *this)
{
- struct inode *inode = dentry->d_inode;
-
if (!ncp_case_sensitive(inode)) {
struct super_block *sb = dentry->d_sb;
struct nls_table *t;
@@ -602,7 +602,7 @@ ncp_fill_cache(struct file *filp, void *
qname.hash = full_name_hash(qname.name, qname.len);
if (dentry->d_op && dentry->d_op->d_hash)
- if (dentry->d_op->d_hash(dentry, &qname) != 0)
+ if (dentry->d_op->d_hash(dentry, dentry->d_inode, &qname) != 0)
goto end_advance;
newdent = d_lookup(dentry, &qname);
Index: linux-2.6/fs/sysv/namei.c
===================================================================
--- linux-2.6.orig/fs/sysv/namei.c 2010-11-17 00:50:53.000000000 +1100
+++ linux-2.6/fs/sysv/namei.c 2010-11-17 00:52:37.000000000 +1100
@@ -27,7 +27,8 @@ static int add_nondir(struct dentry *den
return err;
}
-static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
+static int sysv_hash(const struct dentry *dentry, const struct inode *inode,
+ struct qstr *qstr)
{
/* Truncate the name in place, avoids having to define a compare
function. */
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/include/linux/dcache.h 2010-11-17 01:05:48.000000000 +1100
@@ -133,7 +133,8 @@ enum dentry_d_lock_class
struct dentry_operations {
int (*d_revalidate)(struct dentry *, struct nameidata *);
- int (*d_hash)(struct dentry *, struct qstr *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
int (*d_compare)(const struct dentry *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c 2010-11-17 00:50:52.000000000 +1100
+++ linux-2.6/fs/namei.c 2010-11-17 01:05:46.000000000 +1100
@@ -731,7 +731,8 @@ static int do_lookup(struct nameidata *n
* to use its own hash..
*/
if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) {
- int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name);
+ int err = nd->path.dentry->d_op->d_hash(nd->path.dentry,
+ nd->path.dentry->d_inode, name);
if (err < 0)
return err;
}
@@ -1134,7 +1135,7 @@ static struct dentry *__lookup_hash(stru
* to use its own hash..
*/
if (base->d_op && base->d_op->d_hash) {
- err = base->d_op->d_hash(base, name);
+ err = base->d_op->d_hash(base, inode, name);
dentry = ERR_PTR(err);
if (err < 0)
goto out;
Index: linux-2.6/fs/cifs/readdir.c
===================================================================
--- linux-2.6.orig/fs/cifs/readdir.c 2010-11-17 00:50:52.000000000 +1100
+++ linux-2.6/fs/cifs/readdir.c 2010-11-17 00:52:37.000000000 +1100
@@ -79,7 +79,7 @@ cifs_readdir_lookup(struct dentry *paren
cFYI(1, "For %s", name->name);
if (parent->d_op && parent->d_op->d_hash)
- parent->d_op->d_hash(parent, name);
+ parent->d_op->d_hash(parent, parent->d_inode, name);
else
name->hash = full_name_hash(name->name, name->len);
Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/dcache.c 2010-11-17 01:05:48.000000000 +1100
@@ -1474,7 +1474,7 @@ struct dentry *d_hash_and_lookup(struct
*/
name->hash = full_name_hash(name->name, name->len);
if (dir->d_op && dir->d_op->d_hash) {
- if (dir->d_op->d_hash(dir, name) < 0)
+ if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
goto out;
}
dentry = d_lookup(dir, name);
Index: linux-2.6/fs/ecryptfs/inode.c
===================================================================
--- linux-2.6.orig/fs/ecryptfs/inode.c 2010-11-17 00:50:52.000000000 +1100
+++ linux-2.6/fs/ecryptfs/inode.c 2010-11-17 01:05:47.000000000 +1100
@@ -454,7 +454,7 @@ static struct dentry *ecryptfs_lookup(st
lower_name.hash = ecryptfs_dentry->d_name.hash;
if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
- &lower_name);
+ lower_dir_dentry->d_inode, &lower_name);
if (rc < 0)
goto out_d_drop;
}
@@ -489,7 +489,7 @@ static struct dentry *ecryptfs_lookup(st
lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
- &lower_name);
+ lower_dir_dentry->d_inode, &lower_name);
if (rc < 0)
goto out_d_drop;
}
Index: linux-2.6/Documentation/filesystems/Locking
===================================================================
--- linux-2.6.orig/Documentation/filesystems/Locking 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/Documentation/filesystems/Locking 2010-11-17 01:05:42.000000000 +1100
@@ -10,7 +10,8 @@ be able to use diff(1).
--------------------------- dentry_operations --------------------------
prototypes:
int (*d_revalidate)(struct dentry *, int);
- int (*d_hash) (struct dentry *, struct qstr *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
int (*d_compare)(const struct dentry *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@@ -23,7 +24,7 @@ be able to use diff(1).
none have BKL
dcache_lock rename_lock ->d_lock may block
d_revalidate: no no no yes
-d_hash no no no yes
+d_hash no no no no
d_compare: no yes no no
d_delete: yes no yes no
d_release: no no no yes
Index: linux-2.6/Documentation/filesystems/vfs.txt
===================================================================
--- linux-2.6.orig/Documentation/filesystems/vfs.txt 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/Documentation/filesystems/vfs.txt 2010-11-17 00:52:37.000000000 +1100
@@ -841,7 +841,8 @@ the VFS uses a default. As of kernel 2.6
struct dentry_operations {
int (*d_revalidate)(struct dentry *, struct nameidata *);
- int (*d_hash)(struct dentry *, struct qstr *);
+ int (*d_hash)(const struct dentry *, const struct inode *,
+ struct qstr *);
int (*d_compare)(const struct dentry *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@@ -858,7 +859,10 @@ struct dentry_operations {
d_hash: called when the VFS adds a dentry to the hash table. The first
dentry passed to d_hash is the parent directory that the name is
- to be hashed into.
+ to be hashed into. The inode is the dentry's inode.
+
+ Same locking and synchronisation rules as d_compare regarding
+ what is safe to dereference etc.
d_compare: called to compare a dentry name with a given name. The first
dentry is the parent of the dentry to be compared, the second is
Index: linux-2.6/Documentation/filesystems/porting
===================================================================
--- linux-2.6.orig/Documentation/filesystems/porting 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/Documentation/filesystems/porting 2010-11-17 01:05:42.000000000 +1100
@@ -334,3 +334,10 @@ unreferenced dentries, and is now only c
changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
look at examples of other filesystems) for guidance.
+---
+[mandatory]
+
+ .d_hash() calling convention and locking rules are significantly
+changed. Read updated documentation in Documentation/filesystems/vfs.txt (and
+look at examples of other filesystems) for guidance.
+
On Wed 17 Nov at 01:09:08 +1100 [email protected] said:
> Change d_hash so it may be called from lock-free RCU lookups. See similar
> patch for d_compare for details.
>
> For in-tree filesystems, this is just a mechanical change.
>
> Signed-off-by: Nick Piggin <[email protected]>
>
> ---
> Documentation/filesystems/Locking | 5 +++--
> Documentation/filesystems/porting | 7 +++++++
> Documentation/filesystems/vfs.txt | 8 ++++++--
> fs/dcache.c | 2 +-
> include/linux/dcache.h | 3 ++-
And maybe I'm lazy or something, but it seems like it'd make the reviewing
easier if the above core hunks were formatted in the email before/above
the pages and pages of per fs changes.
--
Tim Pepper <[email protected]>
IBM Linux Technology Center