X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=fs%2Fdcookies.c;h=a21cabdbd87b174c635b584e548fcfbd3d1d1679;hb=7cb36b6ccdca03bd87e8faca7fd920643dd1aec7;hp=855d4b1d619aec6244b182c3669b6efe2ec1f726;hpb=b69409279c4c960fcd1575bcf80f2a0ca414ca93;p=linux-2.6-block.git diff --git a/fs/dcookies.c b/fs/dcookies.c index 855d4b1d619a..a21cabdbd87b 100644 --- a/fs/dcookies.c +++ b/fs/dcookies.c @@ -93,10 +93,15 @@ static struct dcookie_struct *alloc_dcookie(struct path *path) { struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache, GFP_KERNEL); + struct dentry *d; if (!dcs) return NULL; - path->dentry->d_cookie = dcs; + d = path->dentry; + spin_lock(&d->d_lock); + d->d_flags |= DCACHE_COOKIE; + spin_unlock(&d->d_lock); + dcs->path = *path; path_get(path); hash_dcookie(dcs); @@ -119,14 +124,14 @@ int get_dcookie(struct path *path, unsigned long *cookie) goto out; } - dcs = path->dentry->d_cookie; - - if (!dcs) + if (path->dentry->d_flags & DCACHE_COOKIE) { + dcs = find_dcookie((unsigned long)path->dentry); + } else { dcs = alloc_dcookie(path); - - if (!dcs) { - err = -ENOMEM; - goto out; + if (!dcs) { + err = -ENOMEM; + goto out; + } } *cookie = dcookie_value(dcs); @@ -140,7 +145,7 @@ out: /* And here is where the userspace process can look up the cookie value * to retrieve the path. */ -asmlinkage long sys_lookup_dcookie(u64 cookie64, char __user * buf, size_t len) +SYSCALL_DEFINE(lookup_dcookie)(u64 cookie64, char __user * buf, size_t len) { unsigned long cookie = (unsigned long)cookie64; int err = -EINVAL; @@ -193,7 +198,13 @@ out: mutex_unlock(&dcookie_mutex); return err; } - +#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS +asmlinkage long SyS_lookup_dcookie(u64 cookie64, long buf, long len) +{ + return SYSC_lookup_dcookie(cookie64, (char __user *) buf, (size_t) len); +} +SYSCALL_ALIAS(sys_lookup_dcookie, SyS_lookup_dcookie); +#endif static int dcookie_init(void) { @@ -251,7 +262,12 @@ out_kmem: static void free_dcookie(struct dcookie_struct * dcs) { - dcs->path.dentry->d_cookie = NULL; + struct dentry *d = dcs->path.dentry; + + spin_lock(&d->d_lock); + d->d_flags &= ~DCACHE_COOKIE; + spin_unlock(&d->d_lock); + path_put(&dcs->path); kmem_cache_free(dcookie_cache, dcs); }