diff options
Diffstat (limited to 'fs/9p/vfs_dir.c')
| -rw-r--r-- | fs/9p/vfs_dir.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c new file mode 100644 index 000000000..3bb95adc9 --- /dev/null +++ b/fs/9p/vfs_dir.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file contains vfs directory ops for the 9P2000 protocol. + * + * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> + * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> + */ + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/sched.h> +#include <linux/inet.h> +#include <linux/idr.h> +#include <linux/slab.h> +#include <linux/uio.h> +#include <linux/fscache.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> + +#include "v9fs.h" +#include "v9fs_vfs.h" +#include "fid.h" + +/** + * struct p9_rdir - readdir accounting + * @head: start offset of current dirread buffer + * @tail: end offset of current dirread buffer + * @buf: dirread buffer + * + * private structure for keeping track of readdir + * allocated on demand + */ + +struct p9_rdir { + int head; + int tail; + uint8_t buf[]; +}; + +/** + * dt_type - return file type + * @mistat: mistat structure + * + */ + +static inline int dt_type(struct p9_wstat *mistat) +{ + unsigned long perm = mistat->mode; + int rettype = DT_REG; + + if (perm & P9_DMDIR) + rettype = DT_DIR; + if (perm & P9_DMSYMLINK) + rettype = DT_LNK; + + return rettype; +} + +/** + * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir + * @filp: opened file structure + * @buflen: Length in bytes of buffer to allocate + * + */ + +static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen) +{ + struct p9_fid *fid = filp->private_data; + + if (!fid->rdir) + fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL); + return fid->rdir; +} + +/** + * v9fs_dir_readdir - iterate through a directory + * @file: opened file structure + * @ctx: actor we feed the entries to + * + */ + +static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) +{ + bool over; + struct p9_wstat st; + int err = 0; + struct p9_fid *fid; + int buflen; + struct p9_rdir *rdir; + struct kvec kvec; + + p9_debug(P9_DEBUG_VFS, "name %pD\n", file); + fid = file->private_data; + + buflen = fid->clnt->msize - P9_IOHDRSZ; + + rdir = v9fs_alloc_rdir_buf(file, buflen); + if (!rdir) + return -ENOMEM; + kvec.iov_base = rdir->buf; + kvec.iov_len = buflen; + + while (1) { + if (rdir->tail == rdir->head) { + struct iov_iter to; + int n; + + iov_iter_kvec(&to, ITER_DEST, &kvec, 1, buflen); + n = p9_client_read(file->private_data, ctx->pos, &to, + &err); + if (err) + return err; + if (n == 0) + return 0; + + rdir->head = 0; + rdir->tail = n; + } + while (rdir->head < rdir->tail) { + err = p9stat_read(fid->clnt, rdir->buf + rdir->head, + rdir->tail - rdir->head, &st); + if (err <= 0) { + p9_debug(P9_DEBUG_VFS, "returned %d\n", err); + return -EIO; + } + + over = !dir_emit(ctx, st.name, strlen(st.name), + v9fs_qid2ino(&st.qid), dt_type(&st)); + p9stat_free(&st); + if (over) + return 0; + + rdir->head += err; + ctx->pos += err; + } + } +} + +/** + * v9fs_dir_readdir_dotl - iterate through a directory + * @file: opened file structure + * @ctx: actor we feed the entries to + * + */ +static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx) +{ + int err = 0; + struct p9_fid *fid; + int buflen; + struct p9_rdir *rdir; + struct p9_dirent curdirent; + + p9_debug(P9_DEBUG_VFS, "name %pD\n", file); + fid = file->private_data; + + buflen = fid->clnt->msize - P9_READDIRHDRSZ; + + rdir = v9fs_alloc_rdir_buf(file, buflen); + if (!rdir) + return -ENOMEM; + + while (1) { + if (rdir->tail == rdir->head) { + err = p9_client_readdir(fid, rdir->buf, buflen, + ctx->pos); + if (err <= 0) + return err; + + rdir->head = 0; + rdir->tail = err; + } + + while (rdir->head < rdir->tail) { + + err = p9dirent_read(fid->clnt, rdir->buf + rdir->head, + rdir->tail - rdir->head, + &curdirent); + if (err < 0) { + p9_debug(P9_DEBUG_VFS, "returned %d\n", err); + return -EIO; + } + + if (!dir_emit(ctx, curdirent.d_name, + strlen(curdirent.d_name), + v9fs_qid2ino(&curdirent.qid), + curdirent.d_type)) + return 0; + + ctx->pos = curdirent.d_off; + rdir->head += err; + } + } +} + + +/** + * v9fs_dir_release - close a directory + * @inode: inode of the directory + * @filp: file pointer to a directory + * + */ + +int v9fs_dir_release(struct inode *inode, struct file *filp) +{ + struct v9fs_inode *v9inode = V9FS_I(inode); + struct p9_fid *fid; + __le32 version; + loff_t i_size; + + fid = filp->private_data; + p9_debug(P9_DEBUG_VFS, "inode: %p filp: %p fid: %d\n", + inode, filp, fid ? fid->fid : -1); + if (fid) { + spin_lock(&inode->i_lock); + hlist_del(&fid->ilist); + spin_unlock(&inode->i_lock); + p9_fid_put(fid); + } + + if ((filp->f_mode & FMODE_WRITE)) { + version = cpu_to_le32(v9inode->qid.version); + i_size = i_size_read(inode); + fscache_unuse_cookie(v9fs_inode_cookie(v9inode), + &version, &i_size); + } else { + fscache_unuse_cookie(v9fs_inode_cookie(v9inode), NULL, NULL); + } + return 0; +} + +const struct file_operations v9fs_dir_operations = { + .read = generic_read_dir, + .llseek = generic_file_llseek, + .iterate_shared = v9fs_dir_readdir, + .open = v9fs_file_open, + .release = v9fs_dir_release, +}; + +const struct file_operations v9fs_dir_operations_dotl = { + .read = generic_read_dir, + .llseek = generic_file_llseek, + .iterate_shared = v9fs_dir_readdir_dotl, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .fsync = v9fs_file_fsync_dotl, +}; |