terom@6: #include <string.h>
terom@6: #include <errno.h>
terom@6: #include <stdlib.h>
terom@6: #include <assert.h>
terom@6: 
terom@6: #include "simple.h"
terom@8: #include "dirbuf.h"
terom@6: #include "lib/log.h"
terom@9: #include "lib/math.h"
terom@6: #include "lib/misc.h"
terom@6: 
terom@6: struct simple_fs {
terom@6:     const struct simple_node *inode_table;
terom@6: 
terom@6:     size_t inode_count;
terom@6: };
terom@6: 
terom@6: /*
terom@6:  * Used for stat/entry timeouts... not sure how this should really be set.
terom@6:  */
terom@6: #define CACHE_TIMEOUT 1.0
terom@6: 
terom@6: static void _simple_stat (struct stat *stat, const struct simple_node *node) {
terom@6:     stat->st_ino = node->inode;
terom@6:     stat->st_mode = node->mode_type | node->mode_perm;
terom@6:     stat->st_nlink = 1;
terom@6:     stat->st_size = node->data ? strlen(node->data) : 0;
terom@6: }
terom@6: 
terom@8: /*
terom@8:  * Fetch the simple_node for the given inode.
terom@8:  *
terom@8:  * Returns NULL for invalid inodes.
terom@8:  */
terom@8: static const struct simple_node *_simple_get_ino (struct simple_fs *fs, fuse_ino_t ino) {
terom@8:     // make sure it's a valid inode
terom@8:     if (ino < 1 || ino > fs->inode_count) {
terom@8:         WARNING("invalid inode=%zu", ino);
terom@8:         return NULL;
terom@8:     }
terom@8:     
terom@8:     // return the node
terom@8:     return fs->inode_table + (ino - 1);
terom@6: }
terom@6: 
terom@6: static void simple_lookup (fuse_req_t req, fuse_ino_t parent, const char *name) {
terom@6:     struct simple_fs *fs = fuse_req_userdata(req);
terom@6:     const struct simple_node *node;
terom@6:     struct fuse_entry_param e; ZINIT(e);
terom@6:     int err;
terom@6:     
terom@6:     INFO("[simple.lookup %p] parent=%lu, name=`%s'", fs, parent, name);
terom@6: 
terom@6:     // find the matching node
terom@6:     for (node = fs->inode_table; node->inode > 0; node++) {
terom@6:         if (node->parent == parent && strcmp(node->name, name) == 0)
terom@6:             break;
terom@6: 
terom@6:     }
terom@6: 
terom@6:     // did we find it?
terom@6:     if (node->inode) {
terom@6:         // set up the entry
terom@6:         e.ino = node->inode;
terom@6:         e.generation = 0x01;
terom@6:         _simple_stat(&e.attr, node);
terom@6:         e.attr_timeout = CACHE_TIMEOUT;
terom@6:         e.entry_timeout = CACHE_TIMEOUT;
terom@6: 
terom@6:         // reply
terom@6:         if ((err = fuse_reply_entry(req, &e)))
terom@6:             EERROR(err, "fuse_reply_entry");
terom@6: 
terom@6:     } else {
terom@6:         // not found
terom@6:         err = ENOENT;
terom@6:         goto error;
terom@6:     }
terom@6: 
terom@6:     // success
terom@6:     return;
terom@6: 
terom@6: error:
terom@6:     if ((err = fuse_reply_err(req, err)))
terom@6:         EWARNING(err, "fuse_reply_err");
terom@6: }
terom@6: 
terom@6: static void simple_getattr (fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) {
terom@6:     struct simple_fs *fs = fuse_req_userdata(req);
terom@6:     const struct simple_node *node;
terom@6:     struct stat stbuf; ZINIT(stbuf);
terom@6:     int err;
terom@6: 
terom@6:     INFO("[simple.getattr %p] ino=%lu", fs, ino);
terom@6:     
terom@8:     // look up the node 
terom@8:     if ((node = _simple_get_ino(fs, ino)) == NULL)
terom@8:         EERROR(err = EINVAL, "bad inode");
terom@8:     
terom@6:     // set up the stbuf
terom@6:     _simple_stat(&stbuf, node);
terom@6:     
terom@6:     // reply
terom@6:     if ((err = fuse_reply_attr(req, &stbuf, CACHE_TIMEOUT)))
terom@6:         EERROR(err, "fuse_reply_attr");
terom@6:     
terom@6:     // suceccss
terom@6:     return;
terom@6: 
terom@6: error:
terom@6:     if ((err = fuse_reply_err(req, err)))
terom@6:         EWARNING(err, "fuse_reply_err");
terom@6: }
terom@6: 
terom@10: static void simple_readlink (fuse_req_t req, fuse_ino_t ino) {
terom@10:     struct simple_fs *fs = fuse_req_userdata(req);
terom@10:     const struct simple_node *node;
terom@10:     int err;
terom@10: 
terom@10:     INFO("[simple.readlink %p] ino=%lu", fs, ino);
terom@10:     
terom@10:     // look up the node 
terom@10:     if ((node = _simple_get_ino(fs, ino)) == NULL)
terom@10:         EERROR(err = EINVAL, "bad inode");
terom@10: 
terom@10:     // check that it's a symlink
terom@10:     if (node->mode_type != S_IFLNK)
terom@10:         EERROR(err = EINVAL, "bad mode");
terom@10: 
terom@10:     // return the contents
terom@10:     if ((err = fuse_reply_readlink(req, node->data)))
terom@10:         EERROR(err, "fuse_reply_readlink");
terom@10: 
terom@10:     // suceccss
terom@10:     return;
terom@10: 
terom@10: error:
terom@10:     if ((err = fuse_reply_err(req, err)))
terom@10:         EWARNING(err, "fuse_reply_err");
terom@10: 
terom@10: }
terom@10: 
terom@9: static void simple_readdir (fuse_req_t req, fuse_ino_t ino, size_t size, off_t off, struct fuse_file_info *fi) {
terom@8:     struct simple_fs *fs = fuse_req_userdata(req);
terom@8:     const struct simple_node *dir_node, *node;
terom@8:     struct dirbuf buf;
terom@8:     int err;
terom@8: 
terom@8:     INFO("[simple.readdir] ino=%lu, size=%zu, off=%zu, fi=%p", ino, size, off, fi);
terom@8:     
terom@8:     // look up the inode
terom@8:     if ((dir_node = _simple_get_ino(fs, ino)) == NULL)
terom@8:         EERROR(err = EINVAL, "bad inode");
terom@8:     
terom@8:     // check that it's a dir
terom@8:     if (dir_node->mode_type != S_IFDIR)
terom@8:         EERROR(err = ENOTDIR, "bad mode");
terom@8: 
terom@8:     // fill in the dirbuf
terom@8:     if (dirbuf_init(&buf, size))
terom@8:         ERROR("failed to init dirbuf");
terom@8:     
terom@8:     // add . and ..
terom@8:     // we set the next offset to 2, because all dirent offsets will be larger than that
terom@8:     err =   dirbuf_add(req, off, &buf, 0, 1, ".",   dir_node->inode,    S_IFDIR )
terom@8:         ||  dirbuf_add(req, off, &buf, 1, 2, "..",  dir_node->inode,    S_IFDIR );
terom@8:     
terom@8:     if (err != 0)
terom@8:         EERROR(err, "failed to add . and .. dirents");
terom@8: 
terom@8:     // look up all child nodes
terom@8:     for (node = fs->inode_table; node->inode; node++) {
terom@8:         // skip non-children
terom@8:         if (node->parent != dir_node->inode)
terom@8:             continue;
terom@8:         
terom@8:         // child node offsets are just inode + 2
terom@8:         if ((err = dirbuf_add(req, off, &buf, node->inode + 2, node->inode + 3, node->name, node->inode, node->mode_type)) < 0)
terom@8:             EERROR(err, "failed to add dirent for inode=%lu", node->inode);
terom@8:         
terom@8:         // stop if it's full
terom@8:         if (err > 0)
terom@8:             break;
terom@8:     }
terom@8: 
terom@8:     // send it
terom@8:     if ((err = -dirbuf_done(req, &buf)))
terom@8:         EERROR(err, "failed to send buf");
terom@8: 
terom@8:     // success
terom@8:     return;
terom@8: 
terom@8: error:
terom@8:     if ((err = fuse_reply_err(req, err)))
terom@8:         EWARNING(err, "fuse_reply_err");
terom@8: }
terom@6: 
terom@9: static void simple_read (fuse_req_t req, fuse_ino_t ino, size_t size, off_t off, struct fuse_file_info *fi) {
terom@9:     struct simple_fs *fs = fuse_req_userdata(req);
terom@9:     const struct simple_node *node;
terom@9:     int err ;
terom@9: 
terom@9:     // fi is unused
terom@9:     (void) fi;
terom@9: 
terom@9:     INFO("[simple.read] ino=%lu, size=%zu, off=%zu, fi=%p", ino, size, off, fi);
terom@9:     
terom@9:     // look up the inode
terom@9:     if ((node = _simple_get_ino(fs, ino)) == NULL)
terom@9:         EERROR(err = EINVAL, "bad inode");
terom@9:     
terom@9:     // check that it's a dir
terom@9:     if (node->mode_type != S_IFREG)
terom@9:         EERROR(err = (node->mode_type == S_IFDIR ? EISDIR : EINVAL), "bad mode");
terom@9:     
terom@9:     // seek past EOF?
terom@9:     if (off >= strlen(node->data)) {
terom@9:         // offset is out-of-file, so return EOF
terom@9:         if ((err = fuse_reply_buf(req, NULL, 0)))
terom@9:             EERROR(err, "fuse_reply_buf size=0");
terom@9: 
terom@9:     } else {
terom@9:         // reply with the requested file data
terom@9:         if ((err = fuse_reply_buf(req, node->data + off, MIN(strlen(node->data) - off, size))))
terom@9:             EERROR(err, "fuse_reply_buf buf=%p + %zu, size=MIN(%zu, %zu)", node->data, off, strlen(node->data) - off, size);
terom@9:     }
terom@9: 
terom@9:     // success
terom@9:     return;
terom@9: 
terom@9: error:
terom@9:     if ((err = fuse_reply_err(req, err)))
terom@9:         EWARNING(err, "fuse_reply_err");
terom@9: }
terom@9: 
terom@9: 
terom@6: /*
terom@6:  * Define our fuse_lowlevel_ops struct.
terom@6:  */
terom@6: static struct fuse_lowlevel_ops simple_ops = {
terom@6:     .lookup = simple_lookup,
terom@6: 
terom@6:     .getattr = simple_getattr,
terom@8: 
terom@10:     .readlink = simple_readlink,
terom@10: 
terom@8:     .readdir = simple_readdir,
terom@9: 
terom@9:     .read = simple_read,
terom@6: };
terom@6: 
terom@6: struct fuse_lowlevel_ops *simple_init () {
terom@6:     return &simple_ops;
terom@6: }
terom@6: 
terom@6: struct simple_fs *simple_new (const struct simple_node *node_list) {
terom@6:     struct simple_fs *fs = NULL;
terom@6:     const struct simple_node *node;
terom@6:     
terom@6:     // generate
terom@6:     if ((fs = calloc(1, sizeof(*fs))) == NULL)
terom@6:         ERROR("calloc");
terom@6: 
terom@6:     // remember node_list
terom@6:     fs->inode_count = 0;
terom@6:     fs->inode_table = node_list;
terom@6:     
terom@6:     // validate it
terom@6:     for (node = fs->inode_table; node->inode; node++) {
terom@6:         // update inode_count
terom@6:         fs->inode_count++;
terom@6: 
terom@6:         // check that parent is valid
terom@6:         assert(node->inode == fs->inode_count);
terom@6:         assert(node->parent < node->inode);
terom@6:     }
terom@6:     
terom@6:     // success
terom@6:     return fs;
terom@6: 
terom@6: error:
terom@6:     return NULL;
terom@6: }