From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- fs/orangefs/dir.c | 404 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 404 insertions(+) create mode 100644 fs/orangefs/dir.c (limited to 'fs/orangefs/dir.c') diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c new file mode 100644 index 000000000..e2c2699d8 --- /dev/null +++ b/fs/orangefs/dir.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2017 Omnibond Systems, L.L.C. + */ + +#include "protocol.h" +#include "orangefs-kernel.h" +#include "orangefs-bufmap.h" + +struct orangefs_dir_part { + struct orangefs_dir_part *next; + size_t len; +}; + +struct orangefs_dir { + __u64 token; + struct orangefs_dir_part *part; + loff_t end; + int error; +}; + +#define PART_SHIFT (24) +#define PART_SIZE (1<<24) +#define PART_MASK (~(PART_SIZE - 1)) + +/* + * There can be up to 512 directory entries. Each entry is encoded as + * follows: + * 4 bytes: string size (n) + * n bytes: string + * 1 byte: trailing zero + * padding to 8 bytes + * 16 bytes: khandle + * padding to 8 bytes + * + * The trailer_buf starts with a struct orangefs_readdir_response_s + * which must be skipped to get to the directory data. + * + * The data which is received from the userspace daemon is termed a + * part and is stored in a linked list in case more than one part is + * needed for a large directory. + * + * The position pointer (ctx->pos) encodes the part and offset on which + * to begin reading at. Bits above PART_SHIFT encode the part and bits + * below PART_SHIFT encode the offset. Parts are stored in a linked + * list which grows as data is received from the server. The overhead + * associated with managing the list is presumed to be small compared to + * the overhead of communicating with the server. + * + * As data is received from the server, it is placed at the end of the + * part list. Data is parsed from the current position as it is needed. + * When data is determined to be corrupt, it is either because the + * userspace component has sent back corrupt data or because the file + * pointer has been moved to an invalid location. Since the two cannot + * be differentiated, return EIO. + * + * Part zero is synthesized to contains `.' and `..'. Part one is the + * first part of the part list. + */ + +static int do_readdir(struct orangefs_inode_s *oi, + struct orangefs_dir *od, struct dentry *dentry, + struct orangefs_kernel_op_s *op) +{ + struct orangefs_readdir_response_s *resp; + int bufi, r; + + /* + * Despite the badly named field, readdir does not use shared + * memory. However, there are a limited number of readdir + * slots, which must be allocated here. This flag simply tells + * the op scheduler to return the op here for retry. + */ + op->uses_shared_memory = 1; + op->upcall.req.readdir.refn = oi->refn; + op->upcall.req.readdir.token = od->token; + op->upcall.req.readdir.max_dirent_count = + ORANGEFS_MAX_DIRENT_COUNT_READDIR; + +again: + bufi = orangefs_readdir_index_get(); + if (bufi < 0) { + od->error = bufi; + return bufi; + } + + op->upcall.req.readdir.buf_index = bufi; + + r = service_operation(op, "orangefs_readdir", + get_interruptible_flag(dentry->d_inode)); + + orangefs_readdir_index_put(bufi); + + if (op_state_purged(op)) { + if (r == -EAGAIN) { + vfree(op->downcall.trailer_buf); + goto again; + } else if (r == -EIO) { + vfree(op->downcall.trailer_buf); + od->error = r; + return r; + } + } + + if (r < 0) { + vfree(op->downcall.trailer_buf); + od->error = r; + return r; + } else if (op->downcall.status) { + vfree(op->downcall.trailer_buf); + od->error = op->downcall.status; + return op->downcall.status; + } + + /* + * The maximum size is size per entry times the 512 entries plus + * the header. This is well under the limit. + */ + if (op->downcall.trailer_size > PART_SIZE) { + vfree(op->downcall.trailer_buf); + od->error = -EIO; + return -EIO; + } + + resp = (struct orangefs_readdir_response_s *) + op->downcall.trailer_buf; + od->token = resp->token; + return 0; +} + +static int parse_readdir(struct orangefs_dir *od, + struct orangefs_kernel_op_s *op) +{ + struct orangefs_dir_part *part, *new; + size_t count; + + count = 1; + part = od->part; + while (part) { + count++; + if (part->next) + part = part->next; + else + break; + } + + new = (void *)op->downcall.trailer_buf; + new->next = NULL; + new->len = op->downcall.trailer_size - + sizeof(struct orangefs_readdir_response_s); + if (!od->part) + od->part = new; + else + part->next = new; + count++; + od->end = count << PART_SHIFT; + + return 0; +} + +static int orangefs_dir_more(struct orangefs_inode_s *oi, + struct orangefs_dir *od, struct dentry *dentry) +{ + struct orangefs_kernel_op_s *op; + int r; + + op = op_alloc(ORANGEFS_VFS_OP_READDIR); + if (!op) { + od->error = -ENOMEM; + return -ENOMEM; + } + r = do_readdir(oi, od, dentry, op); + if (r) { + od->error = r; + goto out; + } + r = parse_readdir(od, op); + if (r) { + od->error = r; + goto out; + } + + od->error = 0; +out: + op_release(op); + return od->error; +} + +static int fill_from_part(struct orangefs_dir_part *part, + struct dir_context *ctx) +{ + const int offset = sizeof(struct orangefs_readdir_response_s); + struct orangefs_khandle *khandle; + __u32 *len, padlen; + loff_t i; + char *s; + i = ctx->pos & ~PART_MASK; + + /* The file offset from userspace is too large. */ + if (i > part->len) + return 1; + + /* + * If the seek pointer is positioned just before an entry it + * should find the next entry. + */ + if (i % 8) + i = i + (8 - i%8)%8; + + while (i < part->len) { + if (part->len < i + sizeof *len) + break; + len = (void *)part + offset + i; + /* + * len is the size of the string itself. padlen is the + * total size of the encoded string. + */ + padlen = (sizeof *len + *len + 1) + + (8 - (sizeof *len + *len + 1)%8)%8; + if (part->len < i + padlen + sizeof *khandle) + goto next; + s = (void *)part + offset + i + sizeof *len; + if (s[*len] != 0) + goto next; + khandle = (void *)part + offset + i + padlen; + if (!dir_emit(ctx, s, *len, + orangefs_khandle_to_ino(khandle), + DT_UNKNOWN)) + return 0; + i += padlen + sizeof *khandle; + i = i + (8 - i%8)%8; + BUG_ON(i > part->len); + ctx->pos = (ctx->pos & PART_MASK) | i; + continue; +next: + i += 8; + } + return 1; +} + +static int orangefs_dir_fill(struct orangefs_inode_s *oi, + struct orangefs_dir *od, struct dentry *dentry, + struct dir_context *ctx) +{ + struct orangefs_dir_part *part; + size_t count; + + count = ((ctx->pos & PART_MASK) >> PART_SHIFT) - 1; + + part = od->part; + while (part->next && count) { + count--; + part = part->next; + } + /* This means the userspace file offset is invalid. */ + if (count) { + od->error = -EIO; + return -EIO; + } + + while (part && part->len) { + int r; + r = fill_from_part(part, ctx); + if (r < 0) { + od->error = r; + return r; + } else if (r == 0) { + /* Userspace buffer is full. */ + break; + } else { + /* + * The part ran out of data. Move to the next + * part. */ + ctx->pos = (ctx->pos & PART_MASK) + + (1 << PART_SHIFT); + part = part->next; + } + } + return 0; +} + +static loff_t orangefs_dir_llseek(struct file *file, loff_t offset, + int whence) +{ + struct orangefs_dir *od = file->private_data; + /* + * Delete the stored data so userspace sees new directory + * entries. + */ + if (!whence && offset < od->end) { + struct orangefs_dir_part *part = od->part; + while (part) { + struct orangefs_dir_part *next = part->next; + vfree(part); + part = next; + } + od->token = ORANGEFS_ITERATE_START; + od->part = NULL; + od->end = 1 << PART_SHIFT; + } + return default_llseek(file, offset, whence); +} + +static int orangefs_dir_iterate(struct file *file, + struct dir_context *ctx) +{ + struct orangefs_inode_s *oi; + struct orangefs_dir *od; + struct dentry *dentry; + int r; + + dentry = file->f_path.dentry; + oi = ORANGEFS_I(dentry->d_inode); + od = file->private_data; + + if (od->error) + return od->error; + + if (ctx->pos == 0) { + if (!dir_emit_dot(file, ctx)) + return 0; + ctx->pos++; + } + if (ctx->pos == 1) { + if (!dir_emit_dotdot(file, ctx)) + return 0; + ctx->pos = 1 << PART_SHIFT; + } + + /* + * The seek position is in the first synthesized part but is not + * valid. + */ + if ((ctx->pos & PART_MASK) == 0) + return -EIO; + + r = 0; + + /* + * Must read more if the user has sought past what has been read + * so far. Stop a user who has sought past the end. + */ + while (od->token != ORANGEFS_ITERATE_END && + ctx->pos > od->end) { + r = orangefs_dir_more(oi, od, dentry); + if (r) + return r; + } + if (od->token == ORANGEFS_ITERATE_END && ctx->pos > od->end) + return -EIO; + + /* Then try to fill if there's any left in the buffer. */ + if (ctx->pos < od->end) { + r = orangefs_dir_fill(oi, od, dentry, ctx); + if (r) + return r; + } + + /* Finally get some more and try to fill. */ + if (od->token != ORANGEFS_ITERATE_END) { + r = orangefs_dir_more(oi, od, dentry); + if (r) + return r; + r = orangefs_dir_fill(oi, od, dentry, ctx); + } + + return r; +} + +static int orangefs_dir_open(struct inode *inode, struct file *file) +{ + struct orangefs_dir *od; + file->private_data = kmalloc(sizeof(struct orangefs_dir), + GFP_KERNEL); + if (!file->private_data) + return -ENOMEM; + od = file->private_data; + od->token = ORANGEFS_ITERATE_START; + od->part = NULL; + od->end = 1 << PART_SHIFT; + od->error = 0; + return 0; +} + +static int orangefs_dir_release(struct inode *inode, struct file *file) +{ + struct orangefs_dir *od = file->private_data; + struct orangefs_dir_part *part = od->part; + while (part) { + struct orangefs_dir_part *next = part->next; + vfree(part); + part = next; + } + kfree(od); + return 0; +} + +const struct file_operations orangefs_dir_operations = { + .llseek = orangefs_dir_llseek, + .read = generic_read_dir, + .iterate = orangefs_dir_iterate, + .open = orangefs_dir_open, + .release = orangefs_dir_release +}; -- cgit v1.2.3