diff options
Diffstat (limited to 'ext2fs/storeinfo.c')
| -rw-r--r-- | ext2fs/storeinfo.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/ext2fs/storeinfo.c b/ext2fs/storeinfo.c new file mode 100644 index 00000000..ce7bc534 --- /dev/null +++ b/ext2fs/storeinfo.c @@ -0,0 +1,131 @@ +/* Access to file layout information + + Copyright (C) 1996 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 <string.h> +#include <hurd/store.h> + +#include "ext2fs.h" + +error_t +diskfs_S_file_get_storage_info (struct protid *cred, + mach_port_t **ports, + mach_msg_type_name_t *ports_type, + mach_msg_type_number_t *num_ports, + int **ints, mach_msg_type_number_t *num_ints, + off_t **offsets, + mach_msg_type_number_t *num_offsets, + char **data, mach_msg_type_number_t *data_len) +{ + error_t err = 0; + unsigned num_fs_blocks; + struct store *file_store; + struct store_run *runs, *run = 0; + block_t index = 0; + size_t num_runs = 0, runs_alloced = 10; + struct node *node = cred->po->np; + + runs = malloc (runs_alloced * sizeof (struct store_run)); + if (! runs) + return ENOMEM; + + mutex_lock (&node->lock); + + /* NUM_FS_BLOCKS counts down the blocks in the file that we've not + enumerated yet; when it hits zero, we can stop. */ + if (node->dn_stat.st_size < node->dn_stat.st_blocks * 512) + /* The value indicated by st_blocks is too big (because it includes + indirect blocks), so use the size of the file. */ + num_fs_blocks = + (node->dn_stat.st_size + block_size - 1) >> log2_block_size; + else + 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; + } + else if (err) + break; + + block <<= log2_dev_blocks_per_fs_block; + if (num_runs == 0 + || ((block && run->start >= 0) /* Neither is a hole and... */ + ? (block != run->start + run->length) /* BLOCK doesn't follow RUN */ + : (block || run->start >= 0))) /* or one is, but not both */ + /* Add a new run. */ + { + if (num_runs == runs_alloced) + /* Make some more space in RUNS. */ + { + struct store_run *new; + runs_alloced *= 2; + new = realloc (runs, runs_alloced * sizeof (struct store_run)); + if (! new) + { + err = ENOMEM; + break; + } + runs = new; + } + + run = runs + num_runs++; + run->start = block ?: -1; /* -1 means a hole in OFFSETS */ + run->length = 0; /* will get extended just below */ + } + + /* Increase the size of the current run by one filesystem block. */ + run->length += 1 << log2_dev_blocks_per_fs_block; + } + + mutex_unlock (&node->lock); + + if (! err) + err = store_clone (store, &file_store); + if (! err) + { + err = store_remap (file_store, runs, num_runs, &file_store); + if (!err + && !idvec_contains (cred->user->uids, 0) + && !store_is_securely_returnable (file_store, cred->po->openstat)) + { + err = store_set_flags (file_store, STORE_INACTIVE); + if (err == EINVAL) + err = EACCES; + } + if (! err) + { + *ports_type = MACH_MSG_TYPE_COPY_SEND; + err = store_return (file_store, ports, num_ports, ints, num_ints, + offsets, num_offsets, data, data_len); + } + store_free (file_store); + } + + free (runs); + + return err; +} |