diff options
Diffstat (limited to 'include/linux/exportfs.h')
| -rw-r--r-- | include/linux/exportfs.h | 68 |
1 files changed, 65 insertions, 3 deletions
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 1ab165c2939f..f0cf2714ec52 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -3,6 +3,7 @@ #define LINUX_EXPORTFS_H 1 #include <linux/types.h> +#include <linux/path.h> struct dentry; struct iattr; @@ -122,6 +123,12 @@ enum fid_type { FILEID_BCACHEFS_WITH_PARENT = 0xb2, /* + * + * 64 bit namespace identifier, 32 bit namespace type, 32 bit inode number. + */ + FILEID_NSFS = 0xf1, + + /* * 64 bit unique kernfs id */ FILEID_KERNFS = 0xfe, @@ -156,10 +163,34 @@ struct fid { }; }; +enum handle_to_path_flags { + HANDLE_CHECK_PERMS = (1 << 0), + HANDLE_CHECK_SUBTREE = (1 << 1), +}; + +struct handle_to_path_ctx { + struct path root; + enum handle_to_path_flags flags; + unsigned int fh_flags; +}; + #define EXPORT_FH_CONNECTABLE 0x1 /* Encode file handle with parent */ #define EXPORT_FH_FID 0x2 /* File handle may be non-decodeable */ #define EXPORT_FH_DIR_ONLY 0x4 /* Only decode file handle for a directory */ +/* + * Filesystems use only lower 8 bits of file_handle type for fid_type. + * name_to_handle_at() uses upper 16 bits of type as user flags to be + * interpreted by open_by_handle_at(). + */ +#define FILEID_USER_FLAGS_MASK 0xffff0000 +#define FILEID_USER_FLAGS(type) ((type) & FILEID_USER_FLAGS_MASK) + +/* Flags supported in encoded handle_type that is exported to user */ +#define FILEID_IS_CONNECTABLE 0x10000 +#define FILEID_IS_DIR 0x20000 +#define FILEID_VALID_USER_FLAGS (FILEID_IS_CONNECTABLE | FILEID_IS_DIR) + /** * struct export_operations - for nfsd to communicate with file systems * @encode_fh: encode a file handle fragment from a dentry @@ -205,18 +236,24 @@ struct fid { * directory. The name should be stored in the @name (with the * understanding that it is already pointing to a %NAME_MAX+1 sized * buffer. get_name() should return %0 on success, a negative error code - * or error. @get_name will be called without @parent->i_mutex held. + * or error. @get_name will be called without @parent->i_rwsem held. * * get_parent: * @get_parent should find the parent directory for the given @child which * is also a directory. In the event that it cannot be found, or storage * space cannot be allocated, a %ERR_PTR should be returned. * + * permission: + * Allow filesystems to specify a custom permission function. + * + * open: + * Allow filesystems to specify a custom open function. + * * commit_metadata: * @commit_metadata should commit metadata changes to stable storage. * * Locking rules: - * get_parent is called with child->d_inode->i_mutex down + * get_parent is called with child->d_inode->i_rwsem down * get_name is not (which is possibly inconsistent) */ @@ -238,6 +275,8 @@ struct export_operations { bool write, u32 *device_generation); int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, int nr_iomaps, struct iattr *iattr); + int (*permission)(struct handle_to_path_ctx *ctx, unsigned int oflags); + struct file * (*open)(const struct path *path, unsigned int oflags); #define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ #define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ #define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */ @@ -246,10 +285,22 @@ struct export_operations { atomic attribute updates */ #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */ -#define EXPORT_OP_ASYNC_LOCK (0x40) /* fs can do async lock request */ +#define EXPORT_OP_NOLOCKS (0x40) /* no file locking support */ unsigned long flags; }; +/** + * exportfs_cannot_lock() - check if export implements file locking + * @export_ops: the nfs export operations to check + * + * Returns true if the export does not support file locking. + */ +static inline bool +exportfs_cannot_lock(const struct export_operations *export_ops) +{ + return export_ops->flags & EXPORT_OP_NOLOCKS; +} + extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, int *max_len, struct inode *parent, int flags); @@ -276,6 +327,17 @@ static inline bool exportfs_can_encode_fh(const struct export_operations *nop, if (fh_flags & EXPORT_FH_FID) return exportfs_can_encode_fid(nop); + /* Normal file handles cannot be created without export ops */ + if (!nop) + return false; + + /* + * If a connectable file handle was requested, we need to make sure that + * filesystem can also decode connected file handles. + */ + if ((fh_flags & EXPORT_FH_CONNECTABLE) && !nop->fh_to_parent) + return false; + /* * If a decodeable file handle was requested, we need to make sure that * filesystem can also decode file handles. |