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![Jeff Layton](/assets/img/avatar_default.png)
On most filesystems, there is no reason to delay reaping an nfsd_file just because its underlying inode is still under writeback. nfsd just relies on client activity or the local flusher threads to do writeback. The main exception is NFS, which flushes all of its dirty data on last close. Add a new EXPORT_OP_FLUSH_ON_CLOSE flag to allow filesystems to signal that they do this, and only skip closing files under writeback on such filesystems. Also, remove a redundant NULL file pointer check in nfsd_file_check_writeback, and clean up nfs's export op flag definitions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
250 lines
8.2 KiB
C
250 lines
8.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef LINUX_EXPORTFS_H
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#define LINUX_EXPORTFS_H 1
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#include <linux/types.h>
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struct dentry;
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struct iattr;
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struct inode;
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struct iomap;
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struct super_block;
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struct vfsmount;
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/* limit the handle size to NFSv4 handle size now */
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#define MAX_HANDLE_SZ 128
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/*
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* The fileid_type identifies how the file within the filesystem is encoded.
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* In theory this is freely set and parsed by the filesystem, but we try to
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* stick to conventions so we can share some generic code and don't confuse
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* sniffers like ethereal/wireshark.
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*
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* The filesystem must not use the value '0' or '0xff'.
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*/
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enum fid_type {
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/*
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* The root, or export point, of the filesystem.
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* (Never actually passed down to the filesystem.
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*/
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FILEID_ROOT = 0,
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/*
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* 32bit inode number, 32 bit generation number.
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*/
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FILEID_INO32_GEN = 1,
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/*
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* 32bit inode number, 32 bit generation number,
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* 32 bit parent directory inode number.
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*/
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FILEID_INO32_GEN_PARENT = 2,
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/*
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* 64 bit object ID, 64 bit root object ID,
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* 32 bit generation number.
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*/
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FILEID_BTRFS_WITHOUT_PARENT = 0x4d,
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/*
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* 64 bit object ID, 64 bit root object ID,
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* 32 bit generation number,
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* 64 bit parent object ID, 32 bit parent generation.
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*/
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FILEID_BTRFS_WITH_PARENT = 0x4e,
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/*
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* 64 bit object ID, 64 bit root object ID,
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* 32 bit generation number,
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* 64 bit parent object ID, 32 bit parent generation,
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* 64 bit parent root object ID.
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*/
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FILEID_BTRFS_WITH_PARENT_ROOT = 0x4f,
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/*
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* 32 bit block number, 16 bit partition reference,
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* 16 bit unused, 32 bit generation number.
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*/
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FILEID_UDF_WITHOUT_PARENT = 0x51,
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/*
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* 32 bit block number, 16 bit partition reference,
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* 16 bit unused, 32 bit generation number,
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* 32 bit parent block number, 32 bit parent generation number
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*/
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FILEID_UDF_WITH_PARENT = 0x52,
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/*
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* 64 bit checkpoint number, 64 bit inode number,
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* 32 bit generation number.
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*/
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FILEID_NILFS_WITHOUT_PARENT = 0x61,
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/*
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* 64 bit checkpoint number, 64 bit inode number,
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* 32 bit generation number, 32 bit parent generation.
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* 64 bit parent inode number.
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*/
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FILEID_NILFS_WITH_PARENT = 0x62,
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/*
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* 32 bit generation number, 40 bit i_pos.
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*/
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FILEID_FAT_WITHOUT_PARENT = 0x71,
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/*
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* 32 bit generation number, 40 bit i_pos,
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* 32 bit parent generation number, 40 bit parent i_pos
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*/
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FILEID_FAT_WITH_PARENT = 0x72,
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/*
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* 128 bit child FID (struct lu_fid)
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* 128 bit parent FID (struct lu_fid)
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*/
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FILEID_LUSTRE = 0x97,
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/*
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* 64 bit unique kernfs id
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*/
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FILEID_KERNFS = 0xfe,
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/*
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* Filesystems must not use 0xff file ID.
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*/
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FILEID_INVALID = 0xff,
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};
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struct fid {
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union {
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struct {
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u32 ino;
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u32 gen;
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u32 parent_ino;
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u32 parent_gen;
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} i32;
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struct {
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u32 block;
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u16 partref;
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u16 parent_partref;
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u32 generation;
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u32 parent_block;
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u32 parent_generation;
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} udf;
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DECLARE_FLEX_ARRAY(__u32, raw);
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};
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};
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/**
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* struct export_operations - for nfsd to communicate with file systems
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* @encode_fh: encode a file handle fragment from a dentry
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* @fh_to_dentry: find the implied object and get a dentry for it
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* @fh_to_parent: find the implied object's parent and get a dentry for it
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* @get_name: find the name for a given inode in a given directory
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* @get_parent: find the parent of a given directory
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* @commit_metadata: commit metadata changes to stable storage
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*
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* See Documentation/filesystems/nfs/exporting.rst for details on how to use
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* this interface correctly.
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*
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* encode_fh:
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* @encode_fh should store in the file handle fragment @fh (using at most
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* @max_len bytes) information that can be used by @decode_fh to recover the
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* file referred to by the &struct dentry @de. If the @connectable flag is
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* set, the encode_fh() should store sufficient information so that a good
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* attempt can be made to find not only the file but also it's place in the
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* filesystem. This typically means storing a reference to de->d_parent in
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* the filehandle fragment. encode_fh() should return the fileid_type on
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* success and on error returns 255 (if the space needed to encode fh is
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* greater than @max_len*4 bytes). On error @max_len contains the minimum
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* size(in 4 byte unit) needed to encode the file handle.
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*
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* fh_to_dentry:
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* @fh_to_dentry is given a &struct super_block (@sb) and a file handle
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* fragment (@fh, @fh_len). It should return a &struct dentry which refers
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* to the same file that the file handle fragment refers to. If it cannot,
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* it should return a %NULL pointer if the file cannot be found, or an
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* %ERR_PTR error code of %ENOMEM if a memory allocation failure occurred.
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* Any other error code is treated like %NULL, and will cause an %ESTALE error
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* for callers of exportfs_decode_fh().
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* Any suitable dentry can be returned including, if necessary, a new dentry
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* created with d_alloc_root. The caller can then find any other extant
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* dentries by following the d_alias links.
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*
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* fh_to_parent:
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* Same as @fh_to_dentry, except that it returns a pointer to the parent
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* dentry if it was encoded into the filehandle fragment by @encode_fh.
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*
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* get_name:
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* @get_name should find a name for the given @child in the given @parent
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* directory. The name should be stored in the @name (with the
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* understanding that it is already pointing to a %NAME_MAX+1 sized
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* buffer. get_name() should return %0 on success, a negative error code
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* or error. @get_name will be called without @parent->i_mutex held.
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*
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* get_parent:
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* @get_parent should find the parent directory for the given @child which
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* is also a directory. In the event that it cannot be found, or storage
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* space cannot be allocated, a %ERR_PTR should be returned.
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*
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* commit_metadata:
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* @commit_metadata should commit metadata changes to stable storage.
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*
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* Locking rules:
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* get_parent is called with child->d_inode->i_mutex down
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* get_name is not (which is possibly inconsistent)
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*/
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struct export_operations {
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int (*encode_fh)(struct inode *inode, __u32 *fh, int *max_len,
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struct inode *parent);
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struct dentry * (*fh_to_dentry)(struct super_block *sb, struct fid *fid,
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int fh_len, int fh_type);
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struct dentry * (*fh_to_parent)(struct super_block *sb, struct fid *fid,
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int fh_len, int fh_type);
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int (*get_name)(struct dentry *parent, char *name,
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struct dentry *child);
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struct dentry * (*get_parent)(struct dentry *child);
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int (*commit_metadata)(struct inode *inode);
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int (*get_uuid)(struct super_block *sb, u8 *buf, u32 *len, u64 *offset);
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int (*map_blocks)(struct inode *inode, loff_t offset,
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u64 len, struct iomap *iomap,
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bool write, u32 *device_generation);
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int (*commit_blocks)(struct inode *inode, struct iomap *iomaps,
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int nr_iomaps, struct iattr *iattr);
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#define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */
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#define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */
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#define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */
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#define EXPORT_OP_REMOTE_FS (0x8) /* Filesystem is remote */
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#define EXPORT_OP_NOATOMIC_ATTR (0x10) /* Filesystem cannot supply
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atomic attribute updates
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*/
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#define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */
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unsigned long flags;
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};
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extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
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int *max_len, struct inode *parent);
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extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,
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int *max_len, int connectable);
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extern struct dentry *exportfs_decode_fh_raw(struct vfsmount *mnt,
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struct fid *fid, int fh_len,
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int fileid_type,
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int (*acceptable)(void *, struct dentry *),
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void *context);
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extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
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int fh_len, int fileid_type, int (*acceptable)(void *, struct dentry *),
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void *context);
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/*
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* Generic helpers for filesystems.
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*/
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extern struct dentry *generic_fh_to_dentry(struct super_block *sb,
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struct fid *fid, int fh_len, int fh_type,
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struct inode *(*get_inode) (struct super_block *sb, u64 ino, u32 gen));
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extern struct dentry *generic_fh_to_parent(struct super_block *sb,
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struct fid *fid, int fh_len, int fh_type,
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struct inode *(*get_inode) (struct super_block *sb, u64 ino, u32 gen));
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#endif /* LINUX_EXPORTFS_H */
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