2006-09-30 Miklos Szeredi <miklos@szeredi.hu>
+ * kernel changes:
+
* Drop support for kernels earlier than 2.6.9. Kernel module from
previous (2.5.x) release can be used with library from this
release
+ * In fuse_dentry_revalidate() use dget_parent() instead of
+ dereferencing d_parent, since there's no protection against parent
+ changing and going away
+
+ * Protect nlookup from concurrent updates
+
+ * In lookup if a directory alias exists but is unused,
+ then get rid of it, otherwise return -EBUSY.
+
+ * In mkdir if a directory alias exists, return success, but leave
+ dentry negative. In reality this could happen if a remote rename
+ immediately followed the mkdir.
+
+ * Don't BUG in fuse_iget() if multiple retries are needed to get a
+ good inode. This could happen if several lookups are racing for
+ the same inode.
+
2006-09-29 Miklos Szeredi <miklos@szeredi.hu>
* Fix compilation on 2.6.9. Report from Troy Ayers
DISTFILES = Makefile.in configure.ac configure config.h.in ../install-sh \
dev.c dir.c file.c inode.c fuse_i.h fuse_kernel.h control.c
-COMPATDISTFILES = compat/parser.c compat/parser.h
fusemoduledir = @kmoduledir@/kernel/fs/fuse
maintainer-clean: distclean
-distdir: $(DISTFILES) $(COMPATDISTFILES)
+distdir: $(DISTFILES)
cp -p $(DISTFILES) $(distdir)
- mkdir $(distdir)/compat
- cp -p $(COMPATDISTFILES) $(distdir)/compat
EXTRA_CFLAGS += -DFUSE_VERSION=\"$(VERSION)\"
+++ /dev/null
-/*
- * lib/parser.c - simple parser for mount, etc. options.
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2. See the file COPYING for more details.
- */
-
-#include <linux/config.h>
-#ifdef CONFIG_MODVERSIONS
-#define MODVERSIONS
-#include <linux/modversions.h>
-#endif
-
-#include "parser.h"
-
-#include <linux/ctype.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-
-/**
- * match_one: - Determines if a string matches a simple pattern
- * @s: the string to examine for presense of the pattern
- * @p: the string containing the pattern
- * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
- * locations.
- *
- * Description: Determines if the pattern @p is present in string @s. Can only
- * match extremely simple token=arg style patterns. If the pattern is found,
- * the location(s) of the arguments will be returned in the @args array.
- */
-static int match_one(char *s, char *p, substring_t args[])
-{
- char *meta;
- int argc = 0;
-
- if (!p)
- return 1;
-
- while(1) {
- int len = -1;
- meta = strchr(p, '%');
- if (!meta)
- return strcmp(p, s) == 0;
-
- if (strncmp(p, s, meta-p))
- return 0;
-
- s += meta - p;
- p = meta + 1;
-
- if (isdigit(*p))
- len = simple_strtoul(p, &p, 10);
- else if (*p == '%') {
- if (*s++ != '%')
- return 0;
- continue;
- }
-
- if (argc >= MAX_OPT_ARGS)
- return 0;
-
- args[argc].from = s;
- switch (*p++) {
- case 's':
- if (strlen(s) == 0)
- return 0;
- else if (len == -1 || len > strlen(s))
- len = strlen(s);
- args[argc].to = s + len;
- break;
- case 'd':
- simple_strtol(s, &args[argc].to, 0);
- goto num;
- case 'u':
- simple_strtoul(s, &args[argc].to, 0);
- goto num;
- case 'o':
- simple_strtoul(s, &args[argc].to, 8);
- goto num;
- case 'x':
- simple_strtoul(s, &args[argc].to, 16);
- num:
- if (args[argc].to == args[argc].from)
- return 0;
- break;
- default:
- return 0;
- }
- s = args[argc].to;
- argc++;
- }
-}
-
-/**
- * match_token: - Find a token (and optional args) in a string
- * @s: the string to examine for token/argument pairs
- * @table: match_table_t describing the set of allowed option tokens and the
- * arguments that may be associated with them. Must be terminated with a
- * &struct match_token whose pattern is set to the NULL pointer.
- * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
- * locations.
- *
- * Description: Detects which if any of a set of token strings has been passed
- * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style
- * format identifiers which will be taken into account when matching the
- * tokens, and whose locations will be returned in the @args array.
- */
-int match_token(char *s, match_table_t table, substring_t args[])
-{
- struct match_token *p;
-
- for (p = table; !match_one(s, p->pattern, args) ; p++)
- ;
-
- return p->token;
-}
-
-/**
- * match_number: scan a number in the given base from a substring_t
- * @s: substring to be scanned
- * @result: resulting integer on success
- * @base: base to use when converting string
- *
- * Description: Given a &substring_t and a base, attempts to parse the substring
- * as a number in that base. On success, sets @result to the integer represented
- * by the string and returns 0. Returns either -ENOMEM or -EINVAL on failure.
- */
-static int match_number(substring_t *s, int *result, int base)
-{
- char *endp;
- char *buf;
- int ret;
-
- buf = kmalloc(s->to - s->from + 1, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
- memcpy(buf, s->from, s->to - s->from);
- buf[s->to - s->from] = '\0';
- *result = simple_strtol(buf, &endp, base);
- ret = 0;
- if (endp == buf)
- ret = -EINVAL;
- kfree(buf);
- return ret;
-}
-
-/**
- * match_int: - scan a decimal representation of an integer from a substring_t
- * @s: substring_t to be scanned
- * @result: resulting integer on success
- *
- * Description: Attempts to parse the &substring_t @s as a decimal integer. On
- * success, sets @result to the integer represented by the string and returns 0.
- * Returns either -ENOMEM or -EINVAL on failure.
- */
-int match_int(substring_t *s, int *result)
-{
- return match_number(s, result, 0);
-}
-
-/**
- * match_octal: - scan an octal representation of an integer from a substring_t
- * @s: substring_t to be scanned
- * @result: resulting integer on success
- *
- * Description: Attempts to parse the &substring_t @s as an octal integer. On
- * success, sets @result to the integer represented by the string and returns
- * 0. Returns either -ENOMEM or -EINVAL on failure.
- */
-int match_octal(substring_t *s, int *result)
-{
- return match_number(s, result, 8);
-}
-
-/**
- * match_hex: - scan a hex representation of an integer from a substring_t
- * @s: substring_t to be scanned
- * @result: resulting integer on success
- *
- * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
- * On success, sets @result to the integer represented by the string and
- * returns 0. Returns either -ENOMEM or -EINVAL on failure.
- */
-int match_hex(substring_t *s, int *result)
-{
- return match_number(s, result, 16);
-}
-
-/**
- * match_strcpy: - copies the characters from a substring_t to a string
- * @to: string to copy characters to.
- * @s: &substring_t to copy
- *
- * Description: Copies the set of characters represented by the given
- * &substring_t @s to the c-style string @to. Caller guarantees that @to is
- * large enough to hold the characters of @s.
- */
-void match_strcpy(char *to, substring_t *s)
-{
- memcpy(to, s->from, s->to - s->from);
- to[s->to - s->from] = '\0';
-}
-
-/**
- * match_strdup: - allocate a new string with the contents of a substring_t
- * @s: &substring_t to copy
- *
- * Description: Allocates and returns a string filled with the contents of
- * the &substring_t @s. The caller is responsible for freeing the returned
- * string with kfree().
- */
-char *match_strdup(substring_t *s)
-{
- char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL);
- if (p)
- match_strcpy(p, s);
- return p;
-}
-
+++ /dev/null
-/*
- * linux/include/linux/parser.h
- *
- * Header for lib/parser.c
- * Intended use of these functions is parsing filesystem argument lists,
- * but could potentially be used anywhere else that simple option=arg
- * parsing is required.
- */
-
-
-/* associates an integer enumerator with a pattern string. */
-struct match_token {
- int token;
- char *pattern;
-};
-
-typedef struct match_token match_table_t[];
-
-/* Maximum number of arguments that match_token will find in a pattern */
-enum {MAX_OPT_ARGS = 3};
-
-/* Describe the location within a string of a substring */
-typedef struct {
- char *from;
- char *to;
-} substring_t;
-
-int match_token(char *, match_table_t table, substring_t args[]);
-int match_int(substring_t *, int *result);
-int match_octal(substring_t *, int *result);
-int match_hex(substring_t *, int *result);
-void match_strcpy(char *, substring_t *);
-char *match_strdup(substring_t *);
struct fuse_entry_out outarg;
struct fuse_conn *fc;
struct fuse_req *req;
-
- /* Doesn't hurt to "reset" the validity timeout */
- fuse_invalidate_entry_cache(entry);
+ struct dentry *parent;
/* For negative dentries, always do a fresh lookup */
if (!inode)
if (IS_ERR(req))
return 0;
- fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
+ parent = dget_parent(entry);
+ if (!parent->d_inode) {
+ dput(parent);
+ return 0;
+ }
+ fuse_lookup_init(req, parent->d_inode, entry, &outarg);
+ dput(parent);
request_send(fc, req);
err = req->out.h.error;
/* Zero nodeid is same as -ENOENT */
fuse_send_forget(fc, req, outarg.nodeid, 1);
return 0;
}
+ spin_lock(&fc->lock);
fi->nlookup ++;
+ spin_unlock(&fc->lock);
}
fuse_put_request(fc, req);
if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
return 1;
}
-/*
- * Check if there's already a hashed alias of this directory inode.
- * If yes, then lookup and mkdir must not create a new alias.
- */
-static int dir_alias(struct inode *inode)
-{
- if (S_ISDIR(inode->i_mode)) {
- struct dentry *alias = d_find_alias(inode);
-#if defined(FUSE_MAINLINE)
- if (alias) {
- dput(alias);
- return 1;
- }
-#else
- if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
- dput(alias);
- return 1;
- }
- dput(alias);
-#endif
- }
- return 0;
-}
-
static int invalid_nodeid(u64 nodeid)
{
return !nodeid || nodeid == FUSE_ROOT_ID;
int err;
struct fuse_entry_out outarg;
struct inode *inode = NULL;
-#if !defined(FUSE_MAINLINE)
struct dentry *newent;
-#endif
struct fuse_conn *fc = get_fuse_conn(dir);
struct fuse_req *req;
if (err && err != -ENOENT)
return ERR_PTR(err);
- if (inode && dir_alias(inode)) {
- iput(inode);
- return ERR_PTR(-EIO);
- }
-#if defined(FUSE_MAINLINE)
- d_add(entry, inode);
-#else
- newent = d_splice_alias(inode, entry);
+ if (inode && S_ISDIR(inode->i_mode)) {
+ struct dentry *alias;
+ mutex_lock(&fc->inst_mutex);
+ alias = d_find_alias(inode);
+ if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
+ fuse_invalidate_entry(alias);
+ dput(alias);
+ if (!list_empty(&inode->i_dentry)) {
+ mutex_unlock(&fc->inst_mutex);
+ iput(inode);
+ return ERR_PTR(-EBUSY);
+ }
+ } else
+ dput(alias);
+ newent = d_splice_alias(inode, entry);
+ mutex_unlock(&fc->inst_mutex);
+ } else
+ newent = d_splice_alias(inode, entry);
+
entry = newent ? newent : entry;
-#endif
entry->d_op = &fuse_dentry_operations;
if (!err)
fuse_change_timeout(entry, &outarg);
else
fuse_invalidate_entry_cache(entry);
-#if defined(FUSE_MAINLINE)
- return NULL;
-#else
return newent;
-#endif
}
#ifdef HAVE_LOOKUP_INSTANTIATE_FILP
}
fuse_put_request(fc, req);
- if (dir_alias(inode)) {
- iput(inode);
- return -EIO;
- }
+ if (S_ISDIR(inode->i_mode)) {
+ struct dentry *alias;
+ mutex_lock(&fc->inst_mutex);
+ alias = d_find_alias(inode);
+ if (alias) {
+ /* New directory must have moved since mkdir */
+ mutex_unlock(&fc->inst_mutex);
+ dput(alias);
+ iput(inode);
+ fuse_invalidate_entry(entry);
+ return 0;
+ }
+ d_instantiate(entry, inode);
+ mutex_unlock(&fc->inst_mutex);
+ } else
+ d_instantiate(entry, inode);
- d_instantiate(entry, inode);
fuse_change_timeout(entry, &outarg);
fuse_invalidate_attr(dir);
return 0;
#else
#include <asm/semaphore.h>
#define DEFINE_MUTEX(m) DECLARE_MUTEX(m)
+#define mutex_init(m) init_MUTEX(m)
+#define mutex_destroy(m) do { } while (0)
#define mutex_lock(m) down(m)
#define mutex_unlock(m) up(m)
+#define mutex semaphore
#endif
#ifndef BUG_ON
extern struct list_head fuse_conn_list;
/** Global mutex protecting fuse_conn_list and the control filesystem */
-#ifdef KERNEL_2_6_17_PLUS
extern struct mutex fuse_mutex;
-#else
-extern struct semaphore fuse_mutex;
-#endif
/** FUSE inode */
struct fuse_inode {
/** Lock protecting accessess to members of this structure */
spinlock_t lock;
+ /** Mutex protecting against directory alias creation */
+ struct mutex inst_mutex;
+
/** Refcount */
atomic_t count;
if (inode->i_sb->s_flags & MS_ACTIVE) {
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
- fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
- fi->forget_req = NULL;
+ if (fi->nlookup) {
+ fuse_send_forget(fc, fi->forget_req, fi->nodeid,
+ fi->nlookup);
+ fi->forget_req = NULL;
+ }
}
}
struct inode *inode;
struct fuse_inode *fi;
struct fuse_conn *fc = get_fuse_conn_super(sb);
- int retried = 0;
retry:
inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
fuse_init_inode(inode, attr);
unlock_new_inode(inode);
} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
- BUG_ON(retried);
/* Inode has changed type, any I/O on the old should fail */
make_bad_inode(inode);
iput(inode);
- retried = 1;
goto retry;
}
fi = get_fuse_inode(inode);
+ spin_lock(&fc->lock);
fi->nlookup ++;
+ spin_unlock(&fc->lock);
fuse_change_attributes(inode, attr);
return inode;
}
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
if (fc) {
spin_lock_init(&fc->lock);
+ mutex_init(&fc->inst_mutex);
atomic_set(&fc->count, 1);
init_waitqueue_head(&fc->waitq);
init_waitqueue_head(&fc->blocked_waitq);
void fuse_conn_put(struct fuse_conn *fc)
{
- if (atomic_dec_and_test(&fc->count))
+ if (atomic_dec_and_test(&fc->count)) {
+ mutex_destroy(&fc->inst_mutex);
kfree(fc);
+ }
}
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
projects / qemu-gpiodev / libfuse.git / commitdiff