/* FUSE: Filesystem in Userspace Copyright (C) 2001-2018 Miklos Szeredi <miklos@szeredi.hu> This program can be distributed under the terms of the GNU GPL. See the file COPYING.*/ #include "fuse_i.h"#include <linux/iversion.h>#include <linux/posix_acl.h>#include <linux/pagemap.h>#include <linux/highmem.h> static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx){ struct fuse_conn *fc = get_fuse_conn(dir); struct fuse_inode *fi = get_fuse_inode(dir); if (!fc->do_readdirplus) return false; if (!fc->readdirplus_auto) return true; if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) return true; if (ctx->pos == 0) return true; return false;} static void fuse_add_dirent_to_cache(struct file *file, struct fuse_dirent *dirent, loff_t pos){ struct fuse_inode *fi = get_fuse_inode(file_inode(file)); size_t reclen = FUSE_DIRENT_SIZE(dirent); pgoff_t index; struct page *page; loff_t size; u64 version; unsigned int offset; void *addr; spin_lock(&fi->rdc.lock); /* * Is cache already completed? Or this entry does not go at the end of * cache? */ if (fi->rdc.cached || pos != fi->rdc.pos) { spin_unlock(&fi->rdc.lock); return; } version = fi->rdc.version; size = fi->rdc.size; offset = size & ~PAGE_MASK; index = size >> PAGE_SHIFT; /* Dirent doesn't fit in current page? Jump to next page. */ if (offset + reclen > PAGE_SIZE) { index++; offset = 0; } spin_unlock(&fi->rdc.lock); if (offset) { page = find_lock_page(file->f_mapping, index); } else { page = find_or_create_page(file->f_mapping, index, mapping_gfp_mask(file->f_mapping)); } if (!page) return; spin_lock(&fi->rdc.lock); /* Raced with another readdir */ if (fi->rdc.version != version || fi->rdc.size != size || WARN_ON(fi->rdc.pos != pos)) goto unlock; addr = kmap_atomic(page); if (!offset) clear_page(addr); memcpy(addr + offset, dirent, reclen); kunmap_atomic(addr); fi->rdc.size = (index << PAGE_SHIFT) + offset + reclen; fi->rdc.pos = dirent->off;unlock: spin_unlock(&fi->rdc.lock); unlock_page(page); put_page(page);} static void fuse_readdir_cache_end(struct file *file, loff_t pos){ struct fuse_inode *fi = get_fuse_inode(file_inode(file)); loff_t end; spin_lock(&fi->rdc.lock); /* does cache end position match current position? */ if (fi->rdc.pos != pos) { spin_unlock(&fi->rdc.lock); return; } fi->rdc.cached = true; end = ALIGN(fi->rdc.size, PAGE_SIZE); spin_unlock(&fi->rdc.lock); /* truncate unused tail of cache */ truncate_inode_pages(file->f_mapping, end);} static bool fuse_emit(struct file *file, struct dir_context *ctx, struct fuse_dirent *dirent){ struct fuse_file *ff = file->private_data; if (ff->open_flags & FOPEN_CACHE_DIR) fuse_add_dirent_to_cache(file, dirent, ctx->pos); return dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino, dirent->type);} static int parse_dirfile(char *buf, size_t nbytes, struct file *file, struct dir_context *ctx){ while (nbytes >= FUSE_NAME_OFFSET) { struct fuse_dirent *dirent = (struct fuse_dirent *) buf; size_t reclen = FUSE_DIRENT_SIZE(dirent); if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) return -EIO; if (reclen > nbytes) break; if (memchr(dirent->name, '/', dirent->namelen) != NULL) return -EIO; if (!fuse_emit(file, ctx, dirent)) break; buf += reclen; nbytes -= reclen; ctx->pos = dirent->off; } return 0;} static int fuse_direntplus_link(struct file *file, struct fuse_direntplus *direntplus, u64 attr_version){ struct fuse_entry_out *o = &direntplus->entry_out; struct fuse_dirent *dirent = &direntplus->dirent; struct dentry *parent = file->f_path.dentry; struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); struct dentry *dentry; struct dentry *alias; struct inode *dir = d_inode(parent); struct fuse_conn *fc; struct inode *inode; DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); if (!o->nodeid) { /* * Unlike in the case of fuse_lookup, zero nodeid does not mean * ENOENT. Instead, it only means the userspace filesystem did * not want to return attributes/handle for this entry. * * So do nothing. */ return 0; } if (name.name[0] == '.') { /* * We could potentially refresh the attributes of the directory * and its parent? */ if (name.len == 1) return 0; if (name.name[1] == '.' && name.len == 2) return 0; } if (invalid_nodeid(o->nodeid)) return -EIO; if (fuse_invalid_attr(&o->attr)) return -EIO; fc = get_fuse_conn(dir); name.hash = full_name_hash(parent, name.name, name.len); dentry = d_lookup(parent, &name); if (!dentry) {retry: dentry = d_alloc_parallel(parent, &name, &wq); if (IS_ERR(dentry)) return PTR_ERR(dentry); } if (!d_in_lookup(dentry)) { struct fuse_inode *fi; inode = d_inode(dentry); if (!inode || get_node_id(inode) != o->nodeid || ((o->attr.mode ^ inode->i_mode) & S_IFMT)) { d_invalidate(dentry); dput(dentry); goto retry; } if (is_bad_inode(inode)) { dput(dentry); return -EIO; } fi = get_fuse_inode(inode); spin_lock(&fi->lock); fi->nlookup++; spin_unlock(&fi->lock); forget_all_cached_acls(inode); fuse_change_attributes(inode, &o->attr, entry_attr_timeout(o), attr_version); /* * The other branch comes via fuse_iget() * which bumps nlookup inside */ } else { inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, &o->attr, entry_attr_timeout(o), attr_version); if (!inode) inode = ERR_PTR(-ENOMEM); alias = d_splice_alias(inode, dentry); d_lookup_done(dentry); if (alias) { dput(dentry); dentry = alias; } if (IS_ERR(dentry)) return PTR_ERR(dentry); } if (fc->readdirplus_auto) set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state); fuse_change_entry_timeout(dentry, o); dput(dentry); return 0;} static void fuse_force_forget(struct file *file, u64 nodeid){ struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_forget_in inarg; FUSE_ARGS(args); memset(&inarg, 0, sizeof(inarg)); inarg.nlookup = 1; args.opcode = FUSE_FORGET; args.nodeid = nodeid; args.in_numargs = 1; args.in_args[0].size = sizeof(inarg); args.in_args[0].value = &inarg; args.force = true; args.noreply = true; fuse_simple_request(fc, &args); /* ignore errors */} static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, struct dir_context *ctx, u64 attr_version){ struct fuse_direntplus *direntplus; struct fuse_dirent *dirent; size_t reclen; int over = 0; int ret; while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { direntplus = (struct fuse_direntplus *) buf; dirent = &direntplus->dirent; reclen = FUSE_DIRENTPLUS_SIZE(direntplus); if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) return -EIO; if (reclen > nbytes) break; if (memchr(dirent->name, '/', dirent->namelen) != NULL) return -EIO; if (!over) { /* We fill entries into dstbuf only as much as it can hold. But we still continue iterating over remaining entries to link them. If not, we need to send a FORGET for each of those which we did not link. */ over = !fuse_emit(file, ctx, dirent); if (!over) ctx->pos = dirent->off; } buf += reclen; nbytes -= reclen; ret = fuse_direntplus_link(file, direntplus, attr_version); if (ret) fuse_force_forget(file, direntplus->entry_out.nodeid); } return 0;} static int fuse_readdir_uncached(struct file *file, struct dir_context *ctx){ int plus; ssize_t res; struct page *page; struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_io_args ia = {}; struct fuse_args_pages *ap = &ia.ap; struct fuse_page_desc desc = { .length = PAGE_SIZE }; u64 attr_version = 0; bool locked; page = alloc_page(GFP_KERNEL); if (!page) return -ENOMEM; plus = fuse_use_readdirplus(inode, ctx); ap->args.out_pages = true; ap->num_pages = 1; ap->pages = &page; ap->descs = &desc; if (plus) { attr_version = fuse_get_attr_version(fc); fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, FUSE_READDIRPLUS); } else { fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, FUSE_READDIR); } locked = fuse_lock_inode(inode); res = fuse_simple_request(fc, &ap->args); fuse_unlock_inode(inode, locked); if (res >= 0) { if (!res) { struct fuse_file *ff = file->private_data; if (ff->open_flags & FOPEN_CACHE_DIR) fuse_readdir_cache_end(file, ctx->pos); } else if (plus) { res = parse_dirplusfile(page_address(page), res, file, ctx, attr_version); } else { res = parse_dirfile(page_address(page), res, file, ctx); } } __free_page(page); fuse_invalidate_atime(inode); return res;} enum fuse_parse_result { FOUND_ERR = -1, FOUND_NONE = 0, FOUND_SOME, FOUND_ALL,}; static enum fuse_parse_result fuse_parse_cache(struct fuse_file *ff, void *addr, unsigned int size, struct dir_context *ctx){ unsigned int offset = ff->readdir.cache_off & ~PAGE_MASK; enum fuse_parse_result res = FOUND_NONE; WARN_ON(offset >= size); for (;;) { struct fuse_dirent *dirent = addr + offset; unsigned int nbytes = size - offset; size_t reclen; if (nbytes < FUSE_NAME_OFFSET || !dirent->namelen) break; reclen = FUSE_DIRENT_SIZE(dirent); /* derefs ->namelen */ if (WARN_ON(dirent->namelen > FUSE_NAME_MAX)) return FOUND_ERR; if (WARN_ON(reclen > nbytes)) return FOUND_ERR; if (WARN_ON(memchr(dirent->name, '/', dirent->namelen) != NULL)) return FOUND_ERR; if (ff->readdir.pos == ctx->pos) { res = FOUND_SOME; if (!dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino, dirent->type)) return FOUND_ALL; ctx->pos = dirent->off; } ff->readdir.pos = dirent->off; ff->readdir.cache_off += reclen; offset += reclen; } return res;} static void fuse_rdc_reset(struct inode *inode){ struct fuse_inode *fi = get_fuse_inode(inode); fi->rdc.cached = false; fi->rdc.version++; fi->rdc.size = 0; fi->rdc.pos = 0;} #define UNCACHED 1 static int fuse_readdir_cached(struct file *file, struct dir_context *ctx){ struct fuse_file *ff = file->private_data; struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); enum fuse_parse_result res; pgoff_t index; unsigned int size; struct page *page; void *addr; /* Seeked? If so, reset the cache stream */ if (ff->readdir.pos != ctx->pos) { ff->readdir.pos = 0; ff->readdir.cache_off = 0; } /* * We're just about to start reading into the cache or reading the * cache; both cases require an up-to-date mtime value. */ if (!ctx->pos && fc->auto_inval_data) { int err = fuse_update_attributes(inode, file); if (err) return err; } retry: spin_lock(&fi->rdc.lock);retry_locked: if (!fi->rdc.cached) { /* Starting cache? Set cache mtime. */ if (!ctx->pos && !fi->rdc.size) { fi->rdc.mtime = inode->i_mtime; fi->rdc.iversion = inode_query_iversion(inode); } spin_unlock(&fi->rdc.lock); return UNCACHED; } /* * When at the beginning of the directory (i.e. just after opendir(3) or * rewinddir(3)), then need to check whether directory contents have * changed, and reset the cache if so. */ if (!ctx->pos) { if (inode_peek_iversion(inode) != fi->rdc.iversion || !timespec64_equal(&fi->rdc.mtime, &inode->i_mtime)) { fuse_rdc_reset(inode); goto retry_locked; } } /* * If cache version changed since the last getdents() call, then reset * the cache stream. */ if (ff->readdir.version != fi->rdc.version) { ff->readdir.pos = 0; ff->readdir.cache_off = 0; } /* * If at the beginning of the cache, than reset version to * current. */ if (ff->readdir.pos == 0) ff->readdir.version = fi->rdc.version; WARN_ON(fi->rdc.size < ff->readdir.cache_off);Lines 1–500 of 585. Load more
/* FUSE: Filesystem in Userspace Copyright (C) 2001-2018 Miklos Szeredi <miklos@szeredi.hu> This program can be distributed under the terms of the GNU GPL. See the file COPYING. */ #include "fuse_i.h" #include <linux/iversion.h> #include <linux/posix_acl.h> #include <linux/pagemap.h> #include <linux/highmem.h> static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) { struct fuse_conn *fc = get_fuse_conn(dir); struct fuse_inode *fi = get_fuse_inode(dir); if (!fc->do_readdirplus) return false; if (!fc->readdirplus_auto) return true; if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) return true; if (ctx->pos == 0) return true; return false; } static void fuse_add_dirent_to_cache(struct file *file, struct fuse_dirent *dirent, loff_t pos) { struct fuse_inode *fi = get_fuse_inode(file_inode(file)); size_t reclen = FUSE_DIRENT_SIZE(dirent); pgoff_t index; struct page *page; loff_t size; u64 version; unsigned int offset; void *addr; spin_lock(&fi->rdc.lock); /* * Is cache already completed? Or this entry does not go at the end of * cache? */ if (fi->rdc.cached || pos != fi->rdc.pos) { spin_unlock(&fi->rdc.lock); return; } version = fi->rdc.version; size = fi->rdc.size; offset = size & ~PAGE_MASK; index = size >> PAGE_SHIFT; /* Dirent doesn't fit in current page? Jump to next page. */ if (offset + reclen > PAGE_SIZE) { index++; offset = 0; } spin_unlock(&fi->rdc.lock); if (offset) { page = find_lock_page(file->f_mapping, index); } else { page = find_or_create_page(file->f_mapping, index, mapping_gfp_mask(file->f_mapping)); } if (!page) return; spin_lock(&fi->rdc.lock); /* Raced with another readdir */ if (fi->rdc.version != version || fi->rdc.size != size || WARN_ON(fi->rdc.pos != pos)) goto unlock; addr = kmap_atomic(page); if (!offset) clear_page(addr); memcpy(addr + offset, dirent, reclen); kunmap_atomic(addr); fi->rdc.size = (index << PAGE_SHIFT) + offset + reclen; fi->rdc.pos = dirent->off; unlock: spin_unlock(&fi->rdc.lock); unlock_page(page); put_page(page); } static void fuse_readdir_cache_end(struct file *file, loff_t pos) { struct fuse_inode *fi = get_fuse_inode(file_inode(file)); loff_t end; spin_lock(&fi->rdc.lock); /* does cache end position match current position? */ if (fi->rdc.pos != pos) { spin_unlock(&fi->rdc.lock); return; } fi->rdc.cached = true; end = ALIGN(fi->rdc.size, PAGE_SIZE); spin_unlock(&fi->rdc.lock); /* truncate unused tail of cache */ truncate_inode_pages(file->f_mapping, end); } static bool fuse_emit(struct file *file, struct dir_context *ctx, struct fuse_dirent *dirent) { struct fuse_file *ff = file->private_data; if (ff->open_flags & FOPEN_CACHE_DIR) fuse_add_dirent_to_cache(file, dirent, ctx->pos); return dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino, dirent->type); } static int parse_dirfile(char *buf, size_t nbytes, struct file *file, struct dir_context *ctx) { while (nbytes >= FUSE_NAME_OFFSET) { struct fuse_dirent *dirent = (struct fuse_dirent *) buf; size_t reclen = FUSE_DIRENT_SIZE(dirent); if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) return -EIO; if (reclen > nbytes) break; if (memchr(dirent->name, '/', dirent->namelen) != NULL) return -EIO; if (!fuse_emit(file, ctx, dirent)) break; buf += reclen; nbytes -= reclen; ctx->pos = dirent->off; } return 0; } static int fuse_direntplus_link(struct file *file, struct fuse_direntplus *direntplus, u64 attr_version) { struct fuse_entry_out *o = &direntplus->entry_out; struct fuse_dirent *dirent = &direntplus->dirent; struct dentry *parent = file->f_path.dentry; struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); struct dentry *dentry; struct dentry *alias; struct inode *dir = d_inode(parent); struct fuse_conn *fc; struct inode *inode; DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); if (!o->nodeid) { /* * Unlike in the case of fuse_lookup, zero nodeid does not mean * ENOENT. Instead, it only means the userspace filesystem did * not want to return attributes/handle for this entry. * * So do nothing. */ return 0; } if (name.name[0] == '.') { /* * We could potentially refresh the attributes of the directory * and its parent? */ if (name.len == 1) return 0; if (name.name[1] == '.' && name.len == 2) return 0; } if (invalid_nodeid(o->nodeid)) return -EIO; if (fuse_invalid_attr(&o->attr)) return -EIO; fc = get_fuse_conn(dir); name.hash = full_name_hash(parent, name.name, name.len); dentry = d_lookup(parent, &name); if (!dentry) { retry: dentry = d_alloc_parallel(parent, &name, &wq); if (IS_ERR(dentry)) return PTR_ERR(dentry); } if (!d_in_lookup(dentry)) { struct fuse_inode *fi; inode = d_inode(dentry); if (!inode || get_node_id(inode) != o->nodeid || ((o->attr.mode ^ inode->i_mode) & S_IFMT)) { d_invalidate(dentry); dput(dentry); goto retry; } if (is_bad_inode(inode)) { dput(dentry); return -EIO; } fi = get_fuse_inode(inode); spin_lock(&fi->lock); fi->nlookup++; spin_unlock(&fi->lock); forget_all_cached_acls(inode); fuse_change_attributes(inode, &o->attr, entry_attr_timeout(o), attr_version); /* * The other branch comes via fuse_iget() * which bumps nlookup inside */ } else { inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, &o->attr, entry_attr_timeout(o), attr_version); if (!inode) inode = ERR_PTR(-ENOMEM); alias = d_splice_alias(inode, dentry); d_lookup_done(dentry); if (alias) { dput(dentry); dentry = alias; } if (IS_ERR(dentry)) return PTR_ERR(dentry); } if (fc->readdirplus_auto) set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state); fuse_change_entry_timeout(dentry, o); dput(dentry); return 0; } static void fuse_force_forget(struct file *file, u64 nodeid) { struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_forget_in inarg; FUSE_ARGS(args); memset(&inarg, 0, sizeof(inarg)); inarg.nlookup = 1; args.opcode = FUSE_FORGET; args.nodeid = nodeid; args.in_numargs = 1; args.in_args[0].size = sizeof(inarg); args.in_args[0].value = &inarg; args.force = true; args.noreply = true; fuse_simple_request(fc, &args); /* ignore errors */ } static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, struct dir_context *ctx, u64 attr_version) { struct fuse_direntplus *direntplus; struct fuse_dirent *dirent; size_t reclen; int over = 0; int ret; while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { direntplus = (struct fuse_direntplus *) buf; dirent = &direntplus->dirent; reclen = FUSE_DIRENTPLUS_SIZE(direntplus); if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) return -EIO; if (reclen > nbytes) break; if (memchr(dirent->name, '/', dirent->namelen) != NULL) return -EIO; if (!over) { /* We fill entries into dstbuf only as much as it can hold. But we still continue iterating over remaining entries to link them. If not, we need to send a FORGET for each of those which we did not link. */ over = !fuse_emit(file, ctx, dirent); if (!over) ctx->pos = dirent->off; } buf += reclen; nbytes -= reclen; ret = fuse_direntplus_link(file, direntplus, attr_version); if (ret) fuse_force_forget(file, direntplus->entry_out.nodeid); } return 0; } static int fuse_readdir_uncached(struct file *file, struct dir_context *ctx) { int plus; ssize_t res; struct page *page; struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_io_args ia = {}; struct fuse_args_pages *ap = &ia.ap; struct fuse_page_desc desc = { .length = PAGE_SIZE }; u64 attr_version = 0; bool locked; page = alloc_page(GFP_KERNEL); if (!page) return -ENOMEM; plus = fuse_use_readdirplus(inode, ctx); ap->args.out_pages = true; ap->num_pages = 1; ap->pages = &page; ap->descs = &desc; if (plus) { attr_version = fuse_get_attr_version(fc); fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, FUSE_READDIRPLUS); } else { fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, FUSE_READDIR); } locked = fuse_lock_inode(inode); res = fuse_simple_request(fc, &ap->args); fuse_unlock_inode(inode, locked); if (res >= 0) { if (!res) { struct fuse_file *ff = file->private_data; if (ff->open_flags & FOPEN_CACHE_DIR) fuse_readdir_cache_end(file, ctx->pos); } else if (plus) { res = parse_dirplusfile(page_address(page), res, file, ctx, attr_version); } else { res = parse_dirfile(page_address(page), res, file, ctx); } } __free_page(page); fuse_invalidate_atime(inode); return res; } enum fuse_parse_result { FOUND_ERR = -1, FOUND_NONE = 0, FOUND_SOME, FOUND_ALL, }; static enum fuse_parse_result fuse_parse_cache(struct fuse_file *ff, void *addr, unsigned int size, struct dir_context *ctx) { unsigned int offset = ff->readdir.cache_off & ~PAGE_MASK; enum fuse_parse_result res = FOUND_NONE; WARN_ON(offset >= size); for (;;) { struct fuse_dirent *dirent = addr + offset; unsigned int nbytes = size - offset; size_t reclen; if (nbytes < FUSE_NAME_OFFSET || !dirent->namelen) break; reclen = FUSE_DIRENT_SIZE(dirent); /* derefs ->namelen */ if (WARN_ON(dirent->namelen > FUSE_NAME_MAX)) return FOUND_ERR; if (WARN_ON(reclen > nbytes)) return FOUND_ERR; if (WARN_ON(memchr(dirent->name, '/', dirent->namelen) != NULL)) return FOUND_ERR; if (ff->readdir.pos == ctx->pos) { res = FOUND_SOME; if (!dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino, dirent->type)) return FOUND_ALL; ctx->pos = dirent->off; } ff->readdir.pos = dirent->off; ff->readdir.cache_off += reclen; offset += reclen; } return res; } static void fuse_rdc_reset(struct inode *inode) { struct fuse_inode *fi = get_fuse_inode(inode); fi->rdc.cached = false; fi->rdc.version++; fi->rdc.size = 0; fi->rdc.pos = 0; } #define UNCACHED 1 static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) { struct fuse_file *ff = file->private_data; struct inode *inode = file_inode(file); struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); enum fuse_parse_result res; pgoff_t index; unsigned int size; struct page *page; void *addr; /* Seeked? If so, reset the cache stream */ if (ff->readdir.pos != ctx->pos) { ff->readdir.pos = 0; ff->readdir.cache_off = 0; } /* * We're just about to start reading into the cache or reading the * cache; both cases require an up-to-date mtime value. */ if (!ctx->pos && fc->auto_inval_data) { int err = fuse_update_attributes(inode, file); if (err) return err; } retry: spin_lock(&fi->rdc.lock); retry_locked: if (!fi->rdc.cached) { /* Starting cache? Set cache mtime. */ if (!ctx->pos && !fi->rdc.size) { fi->rdc.mtime = inode->i_mtime; fi->rdc.iversion = inode_query_iversion(inode); } spin_unlock(&fi->rdc.lock); return UNCACHED; } /* * When at the beginning of the directory (i.e. just after opendir(3) or * rewinddir(3)), then need to check whether directory contents have * changed, and reset the cache if so. */ if (!ctx->pos) { if (inode_peek_iversion(inode) != fi->rdc.iversion || !timespec64_equal(&fi->rdc.mtime, &inode->i_mtime)) { fuse_rdc_reset(inode); goto retry_locked; } } /* * If cache version changed since the last getdents() call, then reset * the cache stream. */ if (ff->readdir.version != fi->rdc.version) { ff->readdir.pos = 0; ff->readdir.cache_off = 0; } /* * If at the beginning of the cache, than reset version to * current. */ if (ff->readdir.pos == 0) ff->readdir.version = fi->rdc.version; WARN_ON(fi->rdc.size < ff->readdir.cache_off);