From: Trond Myklebust <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/dir.c | 47 ++++++++++++++++++++++++----------------
fs/nfs/internal.h | 2 ++
fs/nfs/nfs4file.c | 39 +++++++++++++++++++++++++++++++++
include/uapi/linux/nfs.h | 11 ++++++++++
4 files changed, 80 insertions(+), 19 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 10a6484c59d3..e8e6a2f7de1f 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -2907,36 +2907,30 @@ void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
}
EXPORT_SYMBOL_GPL(nfs_access_set_mask);
-static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
+int nfs_get_access(struct inode *inode, const struct cred *cred,
+ struct nfs_access_entry *cache, bool may_block)
{
- struct nfs_access_entry cache;
- bool may_block = (mask & MAY_NOT_BLOCK) == 0;
- int cache_mask = -1;
int status;
- trace_nfs_access_enter(inode);
-
- status = nfs_access_get_cached(inode, cred, &cache.mask, may_block);
+ status = nfs_access_get_cached(inode, cred, &cache->mask, may_block);
if (status == 0)
- goto out_cached;
+ return 0;
- status = -ECHILD;
if (!may_block)
- goto out;
-
+ return -ECHILD;
/*
* Determine which access bits we want to ask for...
*/
- cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND;
+ cache->mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND;
if (nfs_server_capable(inode, NFS_CAP_XATTR)) {
- cache.mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE |
+ cache->mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE |
NFS_ACCESS_XALIST;
}
if (S_ISDIR(inode->i_mode))
- cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
+ cache->mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
else
- cache.mask |= NFS_ACCESS_EXECUTE;
- status = NFS_PROTO(inode)->access(inode, &cache, cred);
+ cache->mask |= NFS_ACCESS_EXECUTE;
+ status = NFS_PROTO(inode)->access(inode, cache, cred);
if (status != 0) {
if (status == -ESTALE) {
if (!S_ISDIR(inode->i_mode))
@@ -2944,10 +2938,25 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
else
nfs_zap_caches(inode);
}
- goto out;
+ return status;
}
- nfs_access_add_cache(inode, &cache, cred);
-out_cached:
+ nfs_access_add_cache(inode, cache, cred);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_get_access);
+
+static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
+{
+ struct nfs_access_entry cache;
+ bool may_block = (mask & MAY_NOT_BLOCK) == 0;
+ int cache_mask = -1;
+ int status;
+
+ trace_nfs_access_enter(inode);
+
+ status = nfs_get_access(inode, cred, &cache, may_block);
+ if (status < 0)
+ goto out;
cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
status = -EACCES;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 9602a886f0f0..9b8fd2247533 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -392,6 +392,8 @@ int nfs_mknod(struct user_namespace *, struct inode *, struct dentry *, umode_t,
dev_t);
int nfs_rename(struct user_namespace *, struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
+int nfs_get_access(struct inode *inode, const struct cred *cred,
+ struct nfs_access_entry *cache, bool may_block);
/* file.c */
int nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 494ebc7cd1c0..ccf70d26c5c4 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -611,6 +611,42 @@ static long nfs4_ioctl_file_statx_set(struct file *dst_file,
return ret;
}
+static long
+nfs4_ioctl_file_access_get(struct file *file,
+ struct nfs_ioctl_nfs4_access __user *uarg)
+{
+ struct inode *inode = file_inode(file);
+ struct nfs_access_entry cache;
+ __u64 ac_flags;
+ const struct cred *old_cred;
+ struct cred *override_cred;
+ long ret;
+
+ if (!NFS_PROTO(inode)->access)
+ return -ENOTSUPP;
+
+ if (get_user(ac_flags, &uarg->ac_flags))
+ return -EFAULT;
+
+ override_cred = prepare_creds();
+ if (!override_cred)
+ return -ENOMEM;
+
+ if (!(ac_flags & NFS_AC_FLAG_EACCESS)) {
+ override_cred->fsuid = override_cred->uid;
+ override_cred->fsgid = override_cred->gid;
+ }
+ old_cred = override_creds(override_cred);
+
+ ret = nfs_get_access(inode, override_cred, &cache, true);
+ if (!ret && unlikely(put_user(cache.mask, &uarg->ac_mask) != 0))
+ ret = -EFAULT;
+
+ revert_creds(old_cred);
+ put_cred(override_cred);
+ return ret;
+}
+
static long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
@@ -623,6 +659,9 @@ static long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case NFS_IOC_FILE_STATX_SET:
ret = nfs4_ioctl_file_statx_set(file, argp);
break;
+ case NFS_IOC_FILE_ACCESS_GET:
+ ret = nfs4_ioctl_file_access_get(file, argp);
+ break;
default:
ret = -ENOIOCTLCMD;
}
diff --git a/include/uapi/linux/nfs.h b/include/uapi/linux/nfs.h
index df87da39bc43..b1e50f14db18 100644
--- a/include/uapi/linux/nfs.h
+++ b/include/uapi/linux/nfs.h
@@ -41,6 +41,8 @@
#define NFS_IOC_FILE_STATX_GET _IOR('N', 2, struct nfs_ioctl_nfs4_statx)
#define NFS_IOC_FILE_STATX_SET _IOW('N', 3, struct nfs_ioctl_nfs4_statx)
+#define NFS_IOC_FILE_ACCESS_GET _IOR('N', 4, struct nfs_ioctl_nfs4_access)
+
/* Options for struct nfs_ioctl_nfs4_statx */
#define NFS_FA_OPTIONS_SYNC_AS_STAT 0x0000
#define NFS_FA_OPTIONS_FORCE_SYNC 0x2000 /* See statx */
@@ -125,6 +127,15 @@ struct nfs_ioctl_nfs4_statx {
__u64 fa_padding[4];
};
+struct nfs_ioctl_nfs4_access {
+ /* input */
+ __u64 ac_flags; /* operation flags */
+ /* output */
+ __u64 ac_mask; /* NFS raw ACCESS reply mask */
+};
+
+#define NFS_AC_FLAG_EACCESS (1UL << 0)
+
/*
* NFS stats. The good thing with these values is that NFSv3 errors are
* a superset of NFSv2 errors (with the exception of NFSERR_WFLUSH which
--
2.33.1