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  1. /*
  2.  * Copyright (c) 2008 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup libfs
  30.  * @{
  31.  */
  32. /**
  33.  * @file
  34.  * Glue code which is commonod to all FS implementations.
  35.  */
  36.  
  37. #include "libfs.h"
  38. #include "../../srv/vfs/vfs.h"
  39. #include "../../srv/rd/rd.h"
  40. #include <errno.h>
  41. #include <async.h>
  42. #include <ipc/ipc.h>
  43. #include <as.h>
  44. #include <assert.h>
  45. #include <dirent.h>
  46.  
  47. /** Register file system server.
  48.  *
  49.  * This function abstracts away the tedious registration protocol from
  50.  * file system implementations and lets them to reuse this registration glue
  51.  * code.
  52.  *
  53.  * @param vfs_phone Open phone for communication with VFS.
  54.  * @param reg       File system registration structure. It will be
  55.  *          initialized by this function.
  56.  * @param info      VFS info structure supplied by the file system
  57.  *          implementation.
  58.  * @param conn      Connection fibril for handling all calls originating in
  59.  *          VFS.
  60.  *
  61.  * @return      EOK on success or a non-zero error code on errror.
  62.  */
  63. int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
  64.     async_client_conn_t conn)
  65. {
  66.     /*
  67.      * Tell VFS that we are here and want to get registered.
  68.      * We use the async framework because VFS will answer the request
  69.      * out-of-order, when it knows that the operation succeeded or failed.
  70.      */
  71.     ipc_call_t answer;
  72.     aid_t req = async_send_0(vfs_phone, VFS_REGISTER, &answer);
  73.  
  74.     /*
  75.      * Send our VFS info structure to VFS.
  76.      */
  77.     int rc = ipc_data_write_start(vfs_phone, info, sizeof(*info));
  78.     if (rc != EOK) {
  79.         async_wait_for(req, NULL);
  80.         return rc;
  81.     }
  82.  
  83.     /*
  84.      * Ask VFS for callback connection.
  85.      */
  86.     ipc_connect_to_me(vfs_phone, 0, 0, 0, &reg->vfs_phonehash);
  87.  
  88.     /*
  89.      * Allocate piece of address space for PLB.
  90.      */
  91.     reg->plb_ro = as_get_mappable_page(PLB_SIZE);
  92.     if (!reg->plb_ro) {
  93.         async_wait_for(req, NULL);
  94.         return ENOMEM;
  95.     }
  96.  
  97.     /*
  98.      * Request sharing the Path Lookup Buffer with VFS.
  99.      */
  100.     rc = ipc_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
  101.     if (rc) {
  102.         async_wait_for(req, NULL);
  103.         return rc;
  104.     }
  105.      
  106.     /*
  107.      * Pick up the answer for the request to the VFS_REQUEST call.
  108.      */
  109.     async_wait_for(req, NULL);
  110.     reg->fs_handle = (int) IPC_GET_ARG1(answer);
  111.    
  112.     /*
  113.      * Create a connection fibril to handle the callback connection.
  114.      */
  115.     async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
  116.    
  117.     /*
  118.      * Tell the async framework that other connections are to be handled by
  119.      * the same connection fibril as well.
  120.      */
  121.     async_set_client_connection(conn);
  122.  
  123.     return IPC_GET_RETVAL(answer);
  124. }
  125.  
  126. /** Lookup VFS triplet by name in the file system name space.
  127.  *
  128.  * The path passed in the PLB must be in the canonical file system path format
  129.  * as returned by the canonify() function.
  130.  *
  131.  * @param ops       libfs operations structure with function pointers to
  132.  *          file system implementation
  133.  * @param fs_handle File system handle of the file system where to perform
  134.  *          the lookup.
  135.  * @param rid       Request ID of the VFS_LOOKUP request.
  136.  * @param request   VFS_LOOKUP request data itself.
  137.  */
  138. void libfs_lookup(libfs_ops_t *ops, fs_handle_t fs_handle, ipc_callid_t rid,
  139.     ipc_call_t *request)
  140. {
  141.     unsigned next = IPC_GET_ARG1(*request);
  142.     unsigned last = IPC_GET_ARG2(*request);
  143.     dev_handle_t dev_handle = IPC_GET_ARG3(*request);
  144.     int lflag = IPC_GET_ARG4(*request);
  145.     fs_index_t index = IPC_GET_ARG5(*request); /* when L_LINK specified */
  146.     char component[NAME_MAX + 1];
  147.     int len;
  148.  
  149.     if (last < next)
  150.         last += PLB_SIZE;
  151.  
  152.     void *par = NULL;
  153.     void *cur = ops->root_get(dev_handle);
  154.     void *tmp = NULL;
  155.  
  156.     if (ops->plb_get_char(next) == '/')
  157.         next++;     /* eat slash */
  158.    
  159.     while (next <= last && ops->has_children(cur)) {
  160.         /* collect the component */
  161.         len = 0;
  162.         while ((next <= last) &&  (ops->plb_get_char(next) != '/')) {
  163.             if (len + 1 == NAME_MAX) {
  164.                 /* component length overflow */
  165.                 ipc_answer_0(rid, ENAMETOOLONG);
  166.                 goto out;
  167.             }
  168.             component[len++] = ops->plb_get_char(next);
  169.             next++; /* process next character */
  170.         }
  171.  
  172.         assert(len);
  173.         component[len] = '\0';
  174.         next++;     /* eat slash */
  175.  
  176.         /* match the component */
  177.         tmp = ops->match(cur, component);
  178.  
  179.         /* handle miss: match amongst siblings */
  180.         if (!tmp) {
  181.             if (next <= last) {
  182.                 /* there are unprocessed components */
  183.                 ipc_answer_0(rid, ENOENT);
  184.                 goto out;
  185.             }
  186.             /* miss in the last component */
  187.             if (lflag & (L_CREATE | L_LINK)) {
  188.                 /* request to create a new link */
  189.                 if (!ops->is_directory(cur)) {
  190.                     ipc_answer_0(rid, ENOTDIR);
  191.                     goto out;
  192.                 }
  193.                 void *nodep;
  194.                 if (lflag & L_CREATE)
  195.                     nodep = ops->create(lflag);
  196.                 else
  197.                     nodep = ops->node_get(dev_handle,
  198.                         index);
  199.                 if (nodep) {
  200.                     if (!ops->link(cur, nodep, component)) {
  201.                         if (lflag & L_CREATE) {
  202.                             (void)ops->destroy(
  203.                                 nodep);
  204.                         }
  205.                         ipc_answer_0(rid, ENOSPC);
  206.                     } else {
  207.                         ipc_answer_5(rid, EOK,
  208.                             fs_handle, dev_handle,
  209.                             ops->index_get(nodep),
  210.                             ops->size_get(nodep),
  211.                             ops->lnkcnt_get(nodep));
  212.                         ops->node_put(nodep);
  213.                     }
  214.                 } else {
  215.                     ipc_answer_0(rid, ENOSPC);
  216.                 }
  217.                 goto out;
  218.             } else if (lflag & L_PARENT) {
  219.                 /* return parent */
  220.                 ipc_answer_5(rid, EOK, fs_handle, dev_handle,
  221.                     ops->index_get(cur), ops->size_get(cur),
  222.                     ops->lnkcnt_get(cur));
  223.             }
  224.             ipc_answer_0(rid, ENOENT);
  225.             goto out;
  226.         }
  227.  
  228.         if (par)
  229.             ops->node_put(par);
  230.  
  231.         /* descend one level */
  232.         par = cur;
  233.         cur = tmp;
  234.         tmp = NULL;
  235.     }
  236.  
  237.     /* handle miss: excessive components */
  238.     if (next <= last && !ops->has_children(cur)) {
  239.         if (lflag & (L_CREATE | L_LINK)) {
  240.             if (!ops->is_directory(cur)) {
  241.                 ipc_answer_0(rid, ENOTDIR);
  242.                 goto out;
  243.             }
  244.  
  245.             /* collect next component */
  246.             len = 0;
  247.             while (next <= last) {
  248.                 if (ops->plb_get_char(next) == '/') {
  249.                     /* more than one component */
  250.                     ipc_answer_0(rid, ENOENT);
  251.                     goto out;
  252.                 }
  253.                 if (len + 1 == NAME_MAX) {
  254.                     /* component length overflow */
  255.                     ipc_answer_0(rid, ENAMETOOLONG);
  256.                     goto out;
  257.                 }
  258.                 component[len++] = ops->plb_get_char(next);
  259.                 next++; /* process next character */
  260.             }
  261.             assert(len);
  262.             component[len] = '\0';
  263.                
  264.             void *nodep;
  265.             if (lflag & L_CREATE)
  266.                 nodep = ops->create(lflag);
  267.             else
  268.                 nodep = ops->node_get(dev_handle, index);
  269.             if (nodep) {
  270.                 if (!ops->link(cur, nodep, component)) {
  271.                     if (lflag & L_CREATE)
  272.                         (void)ops->destroy(nodep);
  273.                     ipc_answer_0(rid, ENOSPC);
  274.                 } else {
  275.                     ipc_answer_5(rid, EOK,
  276.                         fs_handle, dev_handle,
  277.                         ops->index_get(nodep),
  278.                         ops->size_get(nodep),
  279.                         ops->lnkcnt_get(nodep));
  280.                     ops->node_put(nodep);
  281.                 }
  282.             } else {
  283.                 ipc_answer_0(rid, ENOSPC);
  284.             }
  285.             goto out;
  286.         }
  287.         ipc_answer_0(rid, ENOENT);
  288.         goto out;
  289.     }
  290.  
  291.     /* handle hit */
  292.     if (lflag & L_PARENT) {
  293.         ops->node_put(cur);
  294.         cur = par;
  295.         par = NULL;
  296.         if (!cur) {
  297.             ipc_answer_0(rid, ENOENT);
  298.             goto out;
  299.         }
  300.     }
  301.     if (lflag & L_UNLINK) {
  302.         unsigned old_lnkcnt = ops->lnkcnt_get(cur);
  303.         int res = ops->unlink(par, cur);
  304.         ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
  305.             ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
  306.         goto out;
  307.     }
  308.     if (((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) ||
  309.         (lflag & L_LINK)) {
  310.         ipc_answer_0(rid, EEXIST);
  311.         goto out;
  312.     }
  313.     if ((lflag & L_FILE) && (ops->is_directory(cur))) {
  314.         ipc_answer_0(rid, EISDIR);
  315.         goto out;
  316.     }
  317.     if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
  318.         ipc_answer_0(rid, ENOTDIR);
  319.         goto out;
  320.     }
  321.  
  322.     ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
  323.         ops->size_get(cur), ops->lnkcnt_get(cur));
  324.  
  325. out:
  326.     if (par)
  327.         ops->node_put(par);
  328.     if (cur)
  329.         ops->node_put(cur);
  330.     if (tmp)
  331.         ops->node_put(tmp);
  332. }
  333.  
  334. /** Read data from a block device.
  335.  *
  336.  * @param phone     Phone to be used to communicate with the device.
  337.  * @param buffer    Communication buffer shared with the device.
  338.  * @param bufpos    Pointer to the first unread valid offset within the
  339.  *          communication buffer.
  340.  * @param buflen    Pointer to the number of unread bytes that are ready in
  341.  *          the communication buffer.
  342.  * @param pos       Device position to be read.
  343.  * @param dst       Destination buffer.
  344.  * @param size      Size of the destination buffer.
  345.  * @param block_size    Block size to be used for the transfer.
  346.  *
  347.  * @return      True on success, false on failure.
  348.  */
  349. bool libfs_blockread(int phone, void *buffer, off_t *bufpos, size_t *buflen,
  350.     off_t *pos, void *dst, size_t size, size_t block_size)
  351. {
  352.     off_t offset = 0;
  353.     size_t left = size;
  354.    
  355.     while (left > 0) {
  356.         size_t rd;
  357.        
  358.         if (*bufpos + left < *buflen)
  359.             rd = left;
  360.         else
  361.             rd = *buflen - *bufpos;
  362.        
  363.         if (rd > 0) {
  364.             /*
  365.              * Copy the contents of the communication buffer to the
  366.              * destination buffer.
  367.              */
  368.             memcpy(dst + offset, buffer + *bufpos, rd);
  369.             offset += rd;
  370.             *bufpos += rd;
  371.             *pos += rd;
  372.             left -= rd;
  373.         }
  374.        
  375.         if (*bufpos == *buflen) {
  376.             /* Refill the communication buffer with a new block. */
  377.             ipcarg_t retval;
  378.             int rc = async_req_2_1(phone, RD_READ_BLOCK,
  379.                 *pos / block_size, block_size, &retval);
  380.             if ((rc != EOK) || (retval != EOK))
  381.                 return false;
  382.            
  383.             *bufpos = 0;
  384.             *buflen = block_size;
  385.         }
  386.     }
  387.    
  388.     return true;
  389. }
  390.  
  391. /** @}
  392.  */
  393.