fs: change d_hash for rcu-walk

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 <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin 2011-01-07 17:49:28 +11:00
parent 621e155a35
commit b1e6a015a5
25 changed files with 94 additions and 51 deletions

View File

@ -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 inode *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@ -22,7 +23,7 @@ prototypes:
locking rules:
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

View File

@ -333,3 +333,10 @@ unreferenced dentries, and is now only called when the dentry refcount goes to
.d_compare() 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.
---
[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.

View File

@ -847,7 +847,8 @@ defined:
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 inode *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@ -864,7 +865,10 @@ 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

View File

@ -134,7 +134,7 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
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, inode, qname) != 0)
goto end_advance;
newdent = d_lookup(dentry, qname);

View File

@ -274,7 +274,8 @@ smb_dir_open(struct inode *dir, struct file *file)
* Dentry operations routines
*/
static int smb_lookup_validate(struct dentry *, struct nameidata *);
static int smb_hash_dentry(struct dentry *, struct qstr *);
static int smb_hash_dentry(const struct dentry *, const struct inode *,
struct qstr *);
static int smb_compare_dentry(const struct dentry *,
const struct inode *,
const struct dentry *, const struct inode *,
@ -336,7 +337,8 @@ smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
}
static int
smb_hash_dentry(struct dentry *dir, struct qstr *this)
smb_hash_dentry(const struct dentry *dir, const struct inode *inode,
struct qstr *this)
{
unsigned long hash;
int i;

View File

@ -201,7 +201,8 @@ const struct file_operations adfs_dir_operations = {
};
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;

View File

@ -13,13 +13,15 @@
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 inode *pinode,
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 inode *pinode,
const struct dentry *dentry, const struct inode *inode,
@ -64,13 +66,13 @@ 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;
@ -84,14 +86,16 @@ __affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
}
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,

View File

@ -700,9 +700,10 @@ const struct dentry_operations cifs_dentry_ops = {
/* 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;

View File

@ -79,7 +79,7 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
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);

View File

@ -1478,7 +1478,7 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
*/
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);

View File

@ -454,7 +454,7 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
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(struct inode *ecryptfs_dir_inode,
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;
}

View File

@ -148,7 +148,8 @@ static int msdos_find(struct inode *dir, const unsigned char *name, int len,
* 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];

View File

@ -103,7 +103,8 @@ static unsigned int vfat_striptail_len(const struct qstr *qstr)
* 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 *dentry, struct qstr *qstr)
* 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;

View File

@ -100,7 +100,8 @@ fail:
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;

View File

@ -213,7 +213,8 @@ extern int hfs_part_find(struct super_block *, sector_t *, sector_t *);
/* 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,

View File

@ -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;

View File

@ -379,7 +379,8 @@ int hfsplus_strcasecmp(const struct hfsplus_unistr *, const struct hfsplus_unist
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 inode *pinode,
const struct dentry *dentry, const struct inode *inode,

View File

@ -320,7 +320,8 @@ int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
* 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;

View File

@ -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;

View File

@ -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 inode *pinode,
const struct dentry *dentry, const struct inode *inode,
@ -38,8 +40,10 @@ static int isofs_dentry_cmp(const struct dentry *parent,
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 inode *pinode,
const struct dentry *dentry, const struct inode *inode,
@ -172,7 +176,7 @@ 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;
@ -193,7 +197,7 @@ isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
* 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;
@ -248,13 +252,15 @@ 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);
}
@ -277,13 +283,15 @@ isofs_dentry_cmpi(const struct dentry *parent, const struct inode *pinode,
#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);
}

View File

@ -1574,7 +1574,8 @@ const struct file_operations jfs_dir_operations = {
.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;

View File

@ -731,7 +731,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
* 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(struct qstr *name,
* 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;

View File

@ -74,7 +74,8 @@ const struct inode_operations ncp_dir_inode_operations =
* 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 inode *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);
@ -129,9 +130,10 @@ static inline int ncp_case_sensitive(const struct inode *i)
* 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)
{
if (!ncp_case_sensitive(dentry->d_inode)) {
if (!ncp_case_sensitive(inode)) {
struct super_block *sb = dentry->d_sb;
struct nls_table *t;
unsigned long hash;
@ -597,7 +599,7 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
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);

View File

@ -27,7 +27,8 @@ static int add_nondir(struct dentry *dentry, struct inode *inode)
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. */

View File

@ -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 inode *,
const struct dentry *, const struct inode *,
unsigned int, const char *, const struct qstr *);