diff options
| -rw-r--r-- | ext2fs/storeinfo.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/ext2fs/storeinfo.c b/ext2fs/storeinfo.c new file mode 100644 index 00000000..bd7e539a --- /dev/null +++ b/ext2fs/storeinfo.c @@ -0,0 +1,146 @@ +/* Access to file layout information + + Copyright (C) 1995 Free Software Foundation, Inc. + + Written by Miles Bader <miles@gnu.ai.mit.edu> + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <netinet/in.h> + +#include "ext2fs.h" + +error_t +diskfs_S_file_get_storage_info (struct protid *cred, int *class, + off_t **runs, unsigned *runs_len, + size_t *block_size, + char *dev_name, mach_port_t *dev_port, + mach_msg_type_name_t *dev_port_type, + char **misc, unsigned *misc_len, + int *flags) +{ + error_t err = 0; + block_t index = 0; + unsigned num_fs_blocks; + unsigned runs_alloced = 0; + off_t *run = 0; + struct node *node = cred->po->np; + + *misc_len = sizeof (long) * 4; + err = vm_allocate (mach_task_self (), (vm_address_t *)misc, *misc_len, 1); + if (err) + return err; + + mutex_lock (&node->lock); + + num_fs_blocks = node->dn_stat.st_blocks >> log2_stat_blocks_per_fs_block; + while (num_fs_blocks > 0) + { + block_t block; + + err = ext2_getblk (node, index++, 0, &block); + if (err == EINVAL) + /* Either a hole, or past the end of the file. */ + { + block = 0; + err = 0; + } + if (err) + goto fail; + + block <<= log2_dev_blocks_per_fs_block; + if (!run + || ((block && run[0] >= 0) /* Neither is a hole and... */ + ? (block != run[0] + run[1]) /* ... BLOCK doesn't follow RUN */ + : (block || run[0] >= 0))) /* or ... one is, but not both */ + /* Add a new run. */ + { + if (run) + /* There are already some runs. */ + { + run += 2; + if (run >= *runs + runs_alloced) + /* Add a new page to the end of the existing RUNS array. */ + { + err = vm_allocate (mach_task_self (), + (vm_address_t *)&run, vm_page_size, 0); + if (err) + goto fail; + runs_alloced += vm_page_size / sizeof (off_t); + } + } + else + /* Allocate the RUNS array for the first time. */ + { + err = vm_allocate (mach_task_self (), + (vm_address_t *)runs, vm_page_size, 1); + if (err) + goto fail; + runs_alloced = vm_page_size / sizeof (off_t); + run = *runs; + } + + run[0] = block ?: -1; /* -1 means a hole in RUNS */ + run[1] = 0; /* will get extended just below */ + } + + /* Increase the size of the current run by one filesystem block. */ + run[1] += 1 << log2_dev_blocks_per_fs_block; + + num_fs_blocks--; + } + + if (run) + { + if (run[0] >= 0) + /* Include the current run, as long as it's not a hole. */ + runs += 2; + else if (((vm_address_t)run % vm_page_size) == 0) + /* We allocated just *one* too many pages -- the last run is a hole. */ + vm_deallocate (mach_task_self (), (vm_address_t)run, vm_page_size); + *runs_len = run - *runs; + } + else + *runs_len = 0; + + ((long *)*misc)[0] = htonl (node->dn->number); + ((long *)*misc)[1] = htonl (dino (node->dn->number)->i_translator); + + *class = STORAGE_DEVICE; + *flags = 0; + + *block_size = diskfs_device_block_size; + + strcpy (dev_name, diskfs_device_name); + + if (diskfs_isuid (0, cred)) + *dev_port = diskfs_device; + else + *dev_port = MACH_PORT_NULL; + *dev_port_type = MACH_MSG_TYPE_COPY_SEND; + + fail: + mutex_unlock (&node->lock); + + if (err) + { + if (*runs_len > 0) + vm_deallocate (mach_task_self (), (vm_address_t)*runs, + runs_alloced * sizeof (off_t)); + vm_deallocate (mach_task_self (), (vm_address_t)*misc, *misc_len); + } + + return err; +} |