| 0,0 → 1,644 |
|---|
| /* |
| * Copyright (c) 2008 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup fs |
| * @{ |
| */ |
| |
| /** |
| * @file tmpfs_ops.c |
| * @brief Implementation of VFS operations for the TMPFS file system |
| * server. |
| */ |
| |
| #include "tmpfs.h" |
| #include "../../vfs/vfs.h" |
| #include <ipc/ipc.h> |
| #include <async.h> |
| #include <errno.h> |
| #include <atomic.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <assert.h> |
| #include <sys/types.h> |
| #include <adt/hash_table.h> |
| #include <as.h> |
| #include <libfs.h> |
| |
| #define min(a, b) ((a) < (b) ? (a) : (b)) |
| #define max(a, b) ((a) > (b) ? (a) : (b)) |
| |
| #define NODES_BUCKETS 256 |
| |
| /** All root nodes have index 0. */ |
| #define TMPFS_SOME_ROOT 0 |
| /** Global counter for assigning node indices. Shared by all instances. */ |
| fs_index_t tmpfs_next_index = 1; |
| |
| /* |
| * Implementation of the libfs interface. |
| */ |
| |
| /* Forward declarations of static functions. */ |
| static fs_node_t *tmpfs_match(fs_node_t *, const char *); |
| static fs_node_t *tmpfs_node_get(dev_handle_t, fs_index_t); |
| static void tmpfs_node_put(fs_node_t *); |
| static fs_node_t *tmpfs_create_node(dev_handle_t, int); |
| static int tmpfs_link_node(fs_node_t *, fs_node_t *, const char *); |
| static int tmpfs_unlink_node(fs_node_t *, fs_node_t *, const char *); |
| static int tmpfs_destroy_node(fs_node_t *); |
| |
| /* Implementation of helper functions. */ |
| static fs_index_t tmpfs_index_get(fs_node_t *fn) |
| { |
| return TMPFS_NODE(fn)->index; |
| } |
| |
| static size_t tmpfs_size_get(fs_node_t *fn) |
| { |
| return TMPFS_NODE(fn)->size; |
| } |
| |
| static unsigned tmpfs_lnkcnt_get(fs_node_t *fn) |
| { |
| return TMPFS_NODE(fn)->lnkcnt; |
| } |
| |
| static bool tmpfs_has_children(fs_node_t *fn) |
| { |
| return !list_empty(&TMPFS_NODE(fn)->cs_head); |
| } |
| |
| static fs_node_t *tmpfs_root_get(dev_handle_t dev_handle) |
| { |
| return tmpfs_node_get(dev_handle, TMPFS_SOME_ROOT); |
| } |
| |
| static char tmpfs_plb_get_char(unsigned pos) |
| { |
| return tmpfs_reg.plb_ro[pos % PLB_SIZE]; |
| } |
| |
| static bool tmpfs_is_directory(fs_node_t *fn) |
| { |
| return TMPFS_NODE(fn)->type == TMPFS_DIRECTORY; |
| } |
| |
| static bool tmpfs_is_file(fs_node_t *fn) |
| { |
| return TMPFS_NODE(fn)->type == TMPFS_FILE; |
| } |
| |
| /** libfs operations */ |
| libfs_ops_t tmpfs_libfs_ops = { |
| .match = tmpfs_match, |
| .node_get = tmpfs_node_get, |
| .node_put = tmpfs_node_put, |
| .create = tmpfs_create_node, |
| .destroy = tmpfs_destroy_node, |
| .link = tmpfs_link_node, |
| .unlink = tmpfs_unlink_node, |
| .index_get = tmpfs_index_get, |
| .size_get = tmpfs_size_get, |
| .lnkcnt_get = tmpfs_lnkcnt_get, |
| .has_children = tmpfs_has_children, |
| .root_get = tmpfs_root_get, |
| .plb_get_char = tmpfs_plb_get_char, |
| .is_directory = tmpfs_is_directory, |
| .is_file = tmpfs_is_file |
| }; |
| |
| /** Hash table of all TMPFS nodes. */ |
| hash_table_t nodes; |
| |
| #define NODES_KEY_INDEX 0 |
| #define NODES_KEY_DEV 1 |
| |
| /* Implementation of hash table interface for the nodes hash table. */ |
| static hash_index_t nodes_hash(unsigned long key[]) |
| { |
| return key[NODES_KEY_INDEX] % NODES_BUCKETS; |
| } |
| |
| static int nodes_compare(unsigned long key[], hash_count_t keys, link_t *item) |
| { |
| tmpfs_node_t *nodep = hash_table_get_instance(item, tmpfs_node_t, |
| nh_link); |
| return (nodep->index == key[NODES_KEY_INDEX] && |
| nodep->dev_handle == key[NODES_KEY_DEV]); |
| } |
| |
| static void nodes_remove_callback(link_t *item) |
| { |
| } |
| |
| /** TMPFS nodes hash table operations. */ |
| hash_table_operations_t nodes_ops = { |
| .hash = nodes_hash, |
| .compare = nodes_compare, |
| .remove_callback = nodes_remove_callback |
| }; |
| |
| static void tmpfs_node_initialize(tmpfs_node_t *nodep) |
| { |
| nodep->bp = NULL; |
| nodep->index = 0; |
| nodep->dev_handle = 0; |
| nodep->type = TMPFS_NONE; |
| nodep->lnkcnt = 0; |
| nodep->size = 0; |
| nodep->data = NULL; |
| link_initialize(&nodep->nh_link); |
| list_initialize(&nodep->cs_head); |
| } |
| |
| static void tmpfs_dentry_initialize(tmpfs_dentry_t *dentryp) |
| { |
| link_initialize(&dentryp->link); |
| dentryp->name = NULL; |
| dentryp->node = NULL; |
| } |
| |
| bool tmpfs_init(void) |
| { |
| if (!hash_table_create(&nodes, NODES_BUCKETS, 2, &nodes_ops)) |
| return false; |
| |
| return true; |
| } |
| |
| static bool tmpfs_instance_init(dev_handle_t dev_handle) |
| { |
| fs_node_t *rfn; |
| |
| rfn = tmpfs_create_node(dev_handle, L_DIRECTORY); |
| if (!rfn) |
| return false; |
| TMPFS_NODE(rfn)->lnkcnt = 0; /* FS root is not linked */ |
| return true; |
| } |
| |
| fs_node_t *tmpfs_match(fs_node_t *pfn, const char *component) |
| { |
| tmpfs_node_t *parentp = TMPFS_NODE(pfn); |
| link_t *lnk; |
| |
| for (lnk = parentp->cs_head.next; lnk != &parentp->cs_head; |
| lnk = lnk->next) { |
| tmpfs_dentry_t *dentryp = list_get_instance(lnk, tmpfs_dentry_t, |
| link); |
| if (!str_cmp(dentryp->name, component)) |
| return FS_NODE(dentryp->node); |
| } |
| |
| return NULL; |
| } |
| |
| fs_node_t *tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index) |
| { |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = index, |
| [NODES_KEY_DEV] = dev_handle |
| }; |
| link_t *lnk = hash_table_find(&nodes, key); |
| if (!lnk) |
| return NULL; |
| return FS_NODE(hash_table_get_instance(lnk, tmpfs_node_t, nh_link)); |
| } |
| |
| void tmpfs_node_put(fs_node_t *fn) |
| { |
| /* nothing to do */ |
| } |
| |
| fs_node_t *tmpfs_create_node(dev_handle_t dev_handle, int lflag) |
| { |
| assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY)); |
| |
| tmpfs_node_t *nodep = malloc(sizeof(tmpfs_node_t)); |
| if (!nodep) |
| return NULL; |
| tmpfs_node_initialize(nodep); |
| nodep->bp = malloc(sizeof(fs_node_t)); |
| if (!nodep->bp) { |
| free(nodep); |
| return NULL; |
| } |
| fs_node_initialize(nodep->bp); |
| nodep->bp->data = nodep; /* link the FS and TMPFS nodes */ |
| if (!tmpfs_root_get(dev_handle)) |
| nodep->index = TMPFS_SOME_ROOT; |
| else |
| nodep->index = tmpfs_next_index++; |
| nodep->dev_handle = dev_handle; |
| if (lflag & L_DIRECTORY) |
| nodep->type = TMPFS_DIRECTORY; |
| else |
| nodep->type = TMPFS_FILE; |
| |
| /* Insert the new node into the nodes hash table. */ |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = nodep->index, |
| [NODES_KEY_DEV] = nodep->dev_handle |
| }; |
| hash_table_insert(&nodes, key, &nodep->nh_link); |
| return FS_NODE(nodep); |
| } |
| |
| int tmpfs_link_node(fs_node_t *pfn, fs_node_t *cfn, const char *nm) |
| { |
| tmpfs_node_t *parentp = TMPFS_NODE(pfn); |
| tmpfs_node_t *childp = TMPFS_NODE(cfn); |
| tmpfs_dentry_t *dentryp; |
| link_t *lnk; |
| |
| assert(parentp->type == TMPFS_DIRECTORY); |
| |
| /* Check for duplicit entries. */ |
| for (lnk = parentp->cs_head.next; lnk != &parentp->cs_head; |
| lnk = lnk->next) { |
| dentryp = list_get_instance(lnk, tmpfs_dentry_t, link); |
| if (!str_cmp(dentryp->name, nm)) |
| return EEXIST; |
| } |
| |
| /* Allocate and initialize the dentry. */ |
| dentryp = malloc(sizeof(tmpfs_dentry_t)); |
| if (!dentryp) |
| return ENOMEM; |
| tmpfs_dentry_initialize(dentryp); |
| |
| /* Populate and link the new dentry. */ |
| size_t size = str_size(nm); |
| dentryp->name = malloc(size + 1); |
| if (!dentryp->name) { |
| free(dentryp); |
| return ENOMEM; |
| } |
| str_cpy(dentryp->name, size + 1, nm); |
| dentryp->node = childp; |
| childp->lnkcnt++; |
| list_append(&dentryp->link, &parentp->cs_head); |
| |
| return EOK; |
| } |
| |
| int tmpfs_unlink_node(fs_node_t *pfn, fs_node_t *cfn, const char *nm) |
| { |
| tmpfs_node_t *parentp = TMPFS_NODE(pfn); |
| tmpfs_node_t *childp = NULL; |
| tmpfs_dentry_t *dentryp; |
| link_t *lnk; |
| |
| if (!parentp) |
| return EBUSY; |
| |
| for (lnk = parentp->cs_head.next; lnk != &parentp->cs_head; |
| lnk = lnk->next) { |
| dentryp = list_get_instance(lnk, tmpfs_dentry_t, link); |
| if (!str_cmp(dentryp->name, nm)) { |
| childp = dentryp->node; |
| assert(FS_NODE(childp) == cfn); |
| break; |
| } |
| } |
| |
| if (!childp) |
| return ENOENT; |
| |
| if ((childp->lnkcnt == 1) && !list_empty(&childp->cs_head)) |
| return ENOTEMPTY; |
| |
| list_remove(&dentryp->link); |
| free(dentryp); |
| childp->lnkcnt--; |
| |
| return EOK; |
| } |
| |
| int tmpfs_destroy_node(fs_node_t *fn) |
| { |
| tmpfs_node_t *nodep = TMPFS_NODE(fn); |
| |
| assert(!nodep->lnkcnt); |
| assert(list_empty(&nodep->cs_head)); |
| |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = nodep->index, |
| [NODES_KEY_DEV] = nodep->dev_handle |
| }; |
| hash_table_remove(&nodes, key, 2); |
| |
| if (nodep->type == TMPFS_FILE) |
| free(nodep->data); |
| free(nodep->bp); |
| free(nodep); |
| return EOK; |
| } |
| |
| void tmpfs_mounted(ipc_callid_t rid, ipc_call_t *request) |
| { |
| dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request); |
| |
| /* accept the mount options */ |
| ipc_callid_t callid; |
| size_t size; |
| if (!ipc_data_write_receive(&callid, &size)) { |
| ipc_answer_0(callid, EINVAL); |
| ipc_answer_0(rid, EINVAL); |
| return; |
| } |
| char *opts = malloc(size + 1); |
| if (!opts) { |
| ipc_answer_0(callid, ENOMEM); |
| ipc_answer_0(rid, ENOMEM); |
| return; |
| } |
| ipcarg_t retval = ipc_data_write_finalize(callid, opts, size); |
| if (retval != EOK) { |
| ipc_answer_0(rid, retval); |
| free(opts); |
| return; |
| } |
| opts[size] = '\0'; |
| |
| /* Initialize TMPFS instance. */ |
| if (!tmpfs_instance_init(dev_handle)) { |
| ipc_answer_0(rid, ENOMEM); |
| return; |
| } |
| |
| tmpfs_node_t *rootp = TMPFS_NODE(tmpfs_root_get(dev_handle)); |
| if (str_cmp(opts, "restore") == 0) { |
| if (tmpfs_restore(dev_handle)) |
| ipc_answer_3(rid, EOK, rootp->index, rootp->size, |
| rootp->lnkcnt); |
| else |
| ipc_answer_0(rid, ELIMIT); |
| } else { |
| ipc_answer_3(rid, EOK, rootp->index, rootp->size, |
| rootp->lnkcnt); |
| } |
| } |
| |
| void tmpfs_mount(ipc_callid_t rid, ipc_call_t *request) |
| { |
| libfs_mount(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request); |
| } |
| |
| void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request) |
| { |
| libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request); |
| } |
| |
| void tmpfs_read(ipc_callid_t rid, ipc_call_t *request) |
| { |
| dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
| fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| off_t pos = (off_t)IPC_GET_ARG3(*request); |
| |
| /* |
| * Lookup the respective TMPFS node. |
| */ |
| link_t *hlp; |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = index, |
| [NODES_KEY_DEV] = dev_handle, |
| }; |
| hlp = hash_table_find(&nodes, key); |
| if (!hlp) { |
| ipc_answer_0(rid, ENOENT); |
| return; |
| } |
| tmpfs_node_t *nodep = hash_table_get_instance(hlp, tmpfs_node_t, |
| nh_link); |
| |
| /* |
| * Receive the read request. |
| */ |
| ipc_callid_t callid; |
| size_t size; |
| if (!ipc_data_read_receive(&callid, &size)) { |
| ipc_answer_0(callid, EINVAL); |
| ipc_answer_0(rid, EINVAL); |
| return; |
| } |
| |
| size_t bytes; |
| if (nodep->type == TMPFS_FILE) { |
| bytes = max(0, min(nodep->size - pos, size)); |
| (void) ipc_data_read_finalize(callid, nodep->data + pos, |
| bytes); |
| } else { |
| tmpfs_dentry_t *dentryp; |
| link_t *lnk; |
| int i; |
| |
| assert(nodep->type == TMPFS_DIRECTORY); |
| |
| /* |
| * Yes, we really use O(n) algorithm here. |
| * If it bothers someone, it could be fixed by introducing a |
| * hash table. |
| */ |
| for (i = 0, lnk = nodep->cs_head.next; |
| i < pos && lnk != &nodep->cs_head; |
| i++, lnk = lnk->next) |
| ; |
| |
| if (lnk == &nodep->cs_head) { |
| ipc_answer_0(callid, ENOENT); |
| ipc_answer_1(rid, ENOENT, 0); |
| return; |
| } |
| |
| dentryp = list_get_instance(lnk, tmpfs_dentry_t, link); |
| |
| (void) ipc_data_read_finalize(callid, dentryp->name, |
| str_size(dentryp->name) + 1); |
| bytes = 1; |
| } |
| |
| /* |
| * Answer the VFS_READ call. |
| */ |
| ipc_answer_1(rid, EOK, bytes); |
| } |
| |
| void tmpfs_write(ipc_callid_t rid, ipc_call_t *request) |
| { |
| dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
| fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| off_t pos = (off_t)IPC_GET_ARG3(*request); |
| |
| /* |
| * Lookup the respective TMPFS node. |
| */ |
| link_t *hlp; |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = index, |
| [NODES_KEY_DEV] = dev_handle |
| }; |
| hlp = hash_table_find(&nodes, key); |
| if (!hlp) { |
| ipc_answer_0(rid, ENOENT); |
| return; |
| } |
| tmpfs_node_t *nodep = hash_table_get_instance(hlp, tmpfs_node_t, |
| nh_link); |
| |
| /* |
| * Receive the write request. |
| */ |
| ipc_callid_t callid; |
| size_t size; |
| if (!ipc_data_write_receive(&callid, &size)) { |
| ipc_answer_0(callid, EINVAL); |
| ipc_answer_0(rid, EINVAL); |
| return; |
| } |
| |
| /* |
| * Check whether the file needs to grow. |
| */ |
| if (pos + size <= nodep->size) { |
| /* The file size is not changing. */ |
| (void) ipc_data_write_finalize(callid, nodep->data + pos, size); |
| ipc_answer_2(rid, EOK, size, nodep->size); |
| return; |
| } |
| size_t delta = (pos + size) - nodep->size; |
| /* |
| * At this point, we are deliberately extremely straightforward and |
| * simply realloc the contents of the file on every write that grows the |
| * file. In the end, the situation might not be as bad as it may look: |
| * our heap allocator can save us and just grow the block whenever |
| * possible. |
| */ |
| void *newdata = realloc(nodep->data, nodep->size + delta); |
| if (!newdata) { |
| ipc_answer_0(callid, ENOMEM); |
| ipc_answer_2(rid, EOK, 0, nodep->size); |
| return; |
| } |
| /* Clear any newly allocated memory in order to emulate gaps. */ |
| memset(newdata + nodep->size, 0, delta); |
| nodep->size += delta; |
| nodep->data = newdata; |
| (void) ipc_data_write_finalize(callid, nodep->data + pos, size); |
| ipc_answer_2(rid, EOK, size, nodep->size); |
| } |
| |
| void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request) |
| { |
| dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
| fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| size_t size = (off_t)IPC_GET_ARG3(*request); |
| |
| /* |
| * Lookup the respective TMPFS node. |
| */ |
| link_t *hlp; |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = index, |
| [NODES_KEY_DEV] = dev_handle |
| }; |
| hlp = hash_table_find(&nodes, key); |
| if (!hlp) { |
| ipc_answer_0(rid, ENOENT); |
| return; |
| } |
| tmpfs_node_t *nodep = hash_table_get_instance(hlp, tmpfs_node_t, |
| nh_link); |
| |
| if (size == nodep->size) { |
| ipc_answer_0(rid, EOK); |
| return; |
| } |
| |
| void *newdata = realloc(nodep->data, size); |
| if (!newdata) { |
| ipc_answer_0(rid, ENOMEM); |
| return; |
| } |
| if (size > nodep->size) { |
| size_t delta = size - nodep->size; |
| memset(newdata + nodep->size, 0, delta); |
| } |
| nodep->size = size; |
| nodep->data = newdata; |
| ipc_answer_0(rid, EOK); |
| } |
| |
| void tmpfs_close(ipc_callid_t rid, ipc_call_t *request) |
| { |
| ipc_answer_0(rid, EOK); |
| } |
| |
| void tmpfs_destroy(ipc_callid_t rid, ipc_call_t *request) |
| { |
| dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request); |
| fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request); |
| int rc; |
| |
| link_t *hlp; |
| unsigned long key[] = { |
| [NODES_KEY_INDEX] = index, |
| [NODES_KEY_DEV] = dev_handle |
| }; |
| hlp = hash_table_find(&nodes, key); |
| if (!hlp) { |
| ipc_answer_0(rid, ENOENT); |
| return; |
| } |
| tmpfs_node_t *nodep = hash_table_get_instance(hlp, tmpfs_node_t, |
| nh_link); |
| rc = tmpfs_destroy_node(FS_NODE(nodep)); |
| ipc_answer_0(rid, rc); |
| } |
| |
| void tmpfs_open_node(ipc_callid_t rid, ipc_call_t *request) |
| { |
| libfs_open_node(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request); |
| } |
| |
| void tmpfs_stat(ipc_callid_t rid, ipc_call_t *request) |
| { |
| libfs_stat(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request); |
| } |
| |
| void tmpfs_sync(ipc_callid_t rid, ipc_call_t *request) |
| { |
| /* Dummy implementation */ |
| ipc_answer_0(rid, EOK); |
| } |
| |
| /** |
| * @} |
| */ |