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-rw-r--r--libstore/file.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/libstore/file.c b/libstore/file.c
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+++ b/libstore/file.c
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+/* File store backend
+
+ Copyright (C) 1995, 96, 97, 98 Free Software Foundation, Inc.
+ Written by Miles Bader <miles@gnu.ai.mit.edu>
+ This file is part of the GNU Hurd.
+
+ The GNU Hurd 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.
+
+ The GNU Hurd 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <hurd.h>
+
+#include <hurd/io.h>
+
+#include "store.h"
+
+static error_t
+file_read (struct store *store,
+ off_t addr, size_t index, size_t amount, void **buf, size_t *len)
+{
+ size_t bsize = store->block_size;
+ return io_read (store->port, (char **)buf, len, addr * bsize, amount);
+}
+
+static error_t
+file_write (struct store *store,
+ off_t addr, size_t index, void *buf, size_t len, size_t *amount)
+{
+ size_t bsize = store->block_size;
+ return io_write (store->port, buf, len, addr * bsize, amount);
+}
+
+static error_t
+file_decode (struct store_enc *enc, const struct store_class *const *classes,
+ struct store **store)
+{
+ return store_std_leaf_decode (enc, _store_file_create, store);
+}
+
+static error_t
+file_open (const char *name, int flags,
+ const struct store_class *const *classes,
+ struct store **store)
+{
+ return store_file_open (name, flags, store);
+}
+
+static error_t
+fiopen (const char *name, file_t *file, int *mod_flags)
+{
+ if (*mod_flags & STORE_HARD_READONLY)
+ *file = file_name_lookup (name, O_RDONLY, 0);
+ else
+ {
+ *file = file_name_lookup (name, O_RDWR, 0);
+ if (*file == MACH_PORT_NULL
+ && (errno == EACCES || errno == EROFS))
+ {
+ *file = file_name_lookup (name, O_RDONLY, 0);
+ if (*file != MACH_PORT_NULL)
+ *mod_flags |= STORE_HARD_READONLY;
+ }
+ else if (*file != MACH_PORT_NULL)
+ *mod_flags &= ~STORE_HARD_READONLY;
+ }
+ return *file == MACH_PORT_NULL ? errno : 0;
+}
+
+static void
+ficlose (struct store *store)
+{
+ mach_port_deallocate (mach_task_self (), store->port);
+ store->port = MACH_PORT_NULL;
+}
+
+/* Return 0 if STORE's range is enforced by the filesystem, otherwise an
+ error. */
+static error_t
+enforced (struct store *store)
+{
+ if (store->num_runs != 1 || store->runs[0].start != 0)
+ /* Can't enforce non-contiguous ranges, or one not starting at 0. */
+ return EINVAL;
+ else
+ /* See if the the current (one) range is that the kernel is enforcing. */
+ {
+ struct stat st;
+ error_t err = io_stat (store->port, &st);
+
+ if (!err
+ && store->runs[0].length != (st.st_size >> store->log2_block_size))
+ /* The single run is not the whole file. */
+ err = EINVAL;
+
+ return err;
+ }
+}
+
+static error_t
+file_set_flags (struct store *store, int flags)
+{
+ if ((flags & ~(STORE_INACTIVE | STORE_ENFORCED)) != 0)
+ /* Trying to set flags we don't support. */
+ return EINVAL;
+
+ if (! ((store->flags | flags) & STORE_INACTIVE))
+ /* Currently active and staying that way, so we must be trying to set the
+ STORE_ENFORCED flag. */
+ {
+ error_t err = enforced (store);
+ if (err)
+ return err;
+ }
+
+ if (flags & STORE_INACTIVE)
+ ficlose (store);
+
+ store->flags |= flags; /* When inactive, anything goes. */
+
+ return 0;
+}
+
+static error_t
+file_clear_flags (struct store *store, int flags)
+{
+ error_t err = 0;
+ if ((flags & ~(STORE_INACTIVE | STORE_ENFORCED)) != 0)
+ err = EINVAL;
+ if (!err && (flags & STORE_INACTIVE))
+ err = store->name
+ ? fiopen (store->name, &store->port, &store->flags)
+ : ENOENT;
+ if (! err)
+ store->flags &= ~flags;
+ return err;
+}
+
+static error_t
+file_map (const struct store *store, vm_prot_t prot, mach_port_t *memobj)
+{
+ error_t err;
+ mach_port_t rd_memobj, wr_memobj;
+ int ro = (store->flags & STORE_HARD_READONLY);
+
+ if (store->num_runs != 1 || store->runs[0].start != 0)
+ return EOPNOTSUPP;
+
+ if ((prot & VM_PROT_WRITE) && ro)
+ return EACCES;
+
+ err = io_map (store->port, &rd_memobj, &wr_memobj);
+ if (err)
+ return err;
+
+ *memobj = rd_memobj;
+
+ if (ro && wr_memobj == MACH_PORT_NULL)
+ return 0;
+ else if (rd_memobj == wr_memobj)
+ {
+ if (rd_memobj != MACH_PORT_NULL)
+ mach_port_mod_refs (mach_task_self (), rd_memobj,
+ MACH_PORT_RIGHT_SEND, -1);
+ }
+ else
+ {
+ if (rd_memobj != MACH_PORT_NULL)
+ mach_port_deallocate (mach_task_self (), rd_memobj);
+ if (wr_memobj != MACH_PORT_NULL)
+ mach_port_deallocate (mach_task_self (), wr_memobj);
+ err = EOPNOTSUPP;
+ }
+
+ return err;
+}
+
+struct store_class
+store_file_class =
+{
+ STORAGE_HURD_FILE, "file", file_read, file_write,
+ store_std_leaf_allocate_encoding, store_std_leaf_encode, file_decode,
+ file_set_flags, file_clear_flags, 0, 0, 0, file_open, 0, file_map
+};
+
+static error_t
+file_byte_read (struct store *store,
+ off_t addr, size_t index, size_t amount,
+ void **buf, size_t *len)
+{
+ return io_read (store->port, (char **)buf, len, addr, amount);
+}
+
+static error_t
+file_byte_write (struct store *store,
+ off_t addr, size_t index, void *buf, size_t len,
+ size_t *amount)
+{
+ return io_write (store->port, buf, len, addr, amount);
+}
+
+struct store_class
+store_file_byte_class =
+{
+ STORAGE_HURD_FILE, "file", file_byte_read, file_byte_write,
+ store_std_leaf_allocate_encoding, store_std_leaf_encode, file_decode,
+ file_set_flags, file_clear_flags, 0, 0, 0, file_open, 0, file_map
+};
+
+/* Return a new store in STORE referring to the mach file FILE. Consumes
+ the send right FILE. */
+error_t
+store_file_create (file_t file, int flags, struct store **store)
+{
+ struct store_run run;
+ struct stat stat;
+ error_t err = io_stat (file, &stat);
+
+ if (err)
+ return err;
+
+ run.start = 0;
+ run.length = stat.st_size;
+
+ flags |= STORE_ENFORCED; /* 'cause it's the whole file. */
+
+ return _store_file_create (file, flags, 1, &run, 1, store);
+}
+
+/* Like store_file_create, but doesn't query the file for information. */
+error_t
+_store_file_create (file_t file, int flags, size_t block_size,
+ const struct store_run *runs, size_t num_runs,
+ struct store **store)
+{
+ if (block_size == 1)
+ return _store_create (&store_file_byte_class,
+ file, flags, 1, runs, num_runs, 0, store);
+ else
+ return _store_create (&store_file_class,
+ file, flags, block_size, runs, num_runs, 0, store);
+}
+
+/* Open the file NAME, and return the corresponding store in STORE. */
+error_t
+store_file_open (const char *name, int flags, struct store **store)
+{
+ file_t file;
+ error_t err = fiopen (name, &file, &flags);
+ if (! err)
+ {
+ err = store_file_create (file, flags, store);
+ if (! err)
+ {
+ err = store_set_name (*store, name);
+ if (err)
+ store_free (*store);
+ }
+ if (err)
+ mach_port_deallocate (mach_task_self (), file);
+ }
+ return err;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-13 17:40:43 +0000