// detach a file from the filesystem
// Only remove a directory if it is empty.
int fs_entry_detach( struct fs_core* core, char const* path, uint64_t user, uint64_t vol ) {
// resolve the parent of this child (and write-lock it)
char* path_dirname = md_dirname( path, NULL );
char* path_basename = md_basename( path, NULL );
int err = 0;
struct fs_entry* parent = fs_entry_resolve_path( core, path_dirname, user, vol, true, &err );
free( path_dirname );
if( parent == NULL ) {
free( path_basename );
return err;
}
if( parent->ftype != FTYPE_DIR ) {
// not a directory
fs_entry_unlock( parent );
free( path_basename );
return -ENOTDIR;
}
if( !IS_DIR_READABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// directory not searchable
fs_entry_unlock( parent );
free( path_basename );
return -EACCES;
}
// is parent writeable?
if( !IS_WRITEABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// nope
fs_entry_unlock( parent );
free( path_basename );
return -EACCES;
}
struct fs_entry* child = fs_entry_set_find_name( parent->children, path_basename );
free( path_basename );
if( child == NULL ) {
// doesn't exist
fs_entry_unlock( parent );
return -ENOENT;
}
int rc = fs_entry_detach_lowlevel( core, parent, child );
fs_entry_unlock( parent );
return rc;
}
// attach a file to the filesystem (same as link())
// THIS METHOD ONLY UPDATES THE METADATA; IT DOES NOT TOUCH STABLE STORAGE
int fs_entry_attach( struct fs_core* core, struct fs_entry* fent, char const* path, uint64_t user, uint64_t vol ) {
// sanity check: path's basename should be fent's name
char* path_base = md_basename( path, NULL );
if( strcmp( fent->name, path_base ) != 0 ) {
free(path_base);
return -EINVAL; // invalid entry
}
free( path_base );
int err = 0;
char* dirname = md_dirname( path, NULL );
struct fs_entry* parent = fs_entry_resolve_path( core, dirname, user, vol, true, &err );
free( dirname );
if( parent == NULL ) {
return err;
}
err = 0;
fs_entry_wlock( fent );
if( !IS_DIR_READABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// directory not searchable
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -EACCES;
}
if( !IS_WRITEABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// not writable--cannot insert
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -EACCES;
}
if( fs_entry_set_find_name( parent->children, fent->name ) == NULL ) {
fs_entry_attach_lowlevel( core, parent, fent );
}
else {
err = -EEXIST;
}
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return err;
}
// revalidate on create (not open)
int fs_entry_create_revalidate( struct fs_core* core, char const* path, uint64_t user, uint64_t vol ) {
int rc = 0;
char* parent_path = md_dirname( path, NULL );
// see that the parent still exists
rc = fs_entry_revalidate_path( core, parent_path );
if( rc != 0 ) {
SG_error("fs_entry_revalidate_path(%s) rc = %d\n", parent_path, rc );
free( parent_path );
return rc;
}
free( parent_path );
return rc;
}
// get the parent and child nodes on create/open, checking permissions along the way
// write-lock the parent.
// do NOT touch the child
// if the child is not found, *child will be set to NULL
// return 0 on success
// return -ENOTDIR if a directory along the path wasn't a directory
// return -EACCES on permission error
int fs_entry_open_parent_and_child( struct fs_core* core, char const* path, uint64_t user, uint64_t vol, struct fs_entry** ret_parent, struct fs_entry** ret_child ) {
// resolve the parent of this child (and write-lock it)
int rc = 0;
char* path_dirname = md_dirname( path, NULL );
char* path_basename = md_basename( path, NULL );
struct fs_entry* parent = fs_entry_resolve_path( core, path_dirname, user, vol, true, &rc );
if( parent == NULL ) {
free( path_basename );
free( path_dirname );
return rc;
}
free( path_dirname );
if( parent->ftype != FTYPE_DIR ) {
// parent is not a directory
fs_entry_unlock( parent );
free( path_basename );
return -ENOTDIR;
}
// can parent be searched?
if( !IS_DIR_READABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// nope
fs_entry_unlock( parent );
free( path_basename );
return -EACCES;
}
// resolve the child
struct fs_entry* child = fs_entry_set_find_name( parent->children, path_basename );
free( path_basename );
*ret_parent = parent;
*ret_child = child;
return 0;
}
// remove a directory, if it is empty
int fs_entry_rmdir( struct fs_core* core, char const* path, uint64_t user, uint64_t volume ) {
if( core->gateway == GATEWAY_ANON ) {
errorf("%s", "Removing directories is forbidden for anonymous gateways\n");
return -EPERM;
}
// get some info about this directory first
int rc = 0;
char* fpath = strdup( path );
md_sanitize_path( fpath );
// revalidate this path
rc = fs_entry_revalidate_path( core, volume, fpath );
if( rc != 0 && rc != -ENOENT ) {
// consistency cannot be guaranteed
errorf("fs_entry_revalidate_path(%s) rc = %d\n", fpath, rc );
free( fpath );
return rc;
}
free( fpath );
int err = 0;
struct fs_entry* dent = fs_entry_resolve_path( core, path, user, volume, false, &err );
if( !dent || err ) {
return err;
}
if( dent->ftype != FTYPE_DIR ) {
fs_entry_unlock( dent );
return -ENOTDIR;
}
char* path_dirname = md_dirname( path, NULL );
struct fs_entry* parent = fs_entry_resolve_path( core, path_dirname, user, volume, true, &err );
free( path_dirname );
if( !parent || err ) {
fs_entry_unlock( dent );
return err;
}
// IS THE PARENT EMPTY?
if( fs_entry_set_count( dent->children ) > 2 ) {
// nope
fs_entry_unlock( dent );
fs_entry_unlock( parent );
return -ENOTEMPTY;
}
struct md_entry ent;
fs_entry_to_md_entry( core, &ent, dent, parent->file_id, parent->name );
// tell the MS that this directory should go away
rc = ms_client_delete( core->ms, &ent );
md_entry_free( &ent );
if( rc != 0 ) {
errorf( "ms_client_delete(%s) rc = %d\n", path, rc );
rc = -EREMOTEIO;
fs_entry_unlock( dent );
fs_entry_unlock( parent );
}
else {
fs_entry_unlock( dent );
// detach from the filesystem
rc = fs_entry_detach_lowlevel( core, parent, dent );
if( rc != 0 ) {
errorf("fs_entry_detach_lowlevel(%s) rc = %d\n", path, rc );
}
fs_entry_unlock( parent );
}
return rc;
}
// unlink a file from the filesystem
// pass -1 if the version is not known, or pass the known version to be unlinked
// return -EUCLEAN if we failed to garbage-collect, but needed to (i.e. a manifest was missing)
// return -EREMOTEIO for failure to revalidate metadata
// return -ESTALE if the given information is out of date
int fs_entry_versioned_unlink( struct fs_core* core, char const* path, uint64_t file_id, uint64_t coordinator_id, int64_t known_version, uint64_t owner, uint64_t volume, uint64_t gateway_id,
bool check_file_id_and_coordinator_id ) {
// can't modify state if anonymous
if( core->gateway == SG_GATEWAY_ANON ) {
SG_error("%s", "Writing is forbidden for anonymous gateways\n");
return -EPERM;
}
// get some info about this file first
int rc = 0;
int err = 0;
bool no_manifest = false;
// consistency check
err = fs_entry_revalidate_path( core, path );
if( err != 0 ) {
SG_error("fs_entry_revalidate_path(%s) rc = %d\n", path, err );
if( err == -ENOENT )
return -ENOENT;
return -EREMOTEIO;
}
// look up the parent
char* path_dirname = md_dirname( path, NULL );
char* path_basename = md_basename( path, NULL );
struct fs_entry* parent = fs_entry_resolve_path( core, path_dirname, owner, volume, true, &err );
free( path_dirname );
if( !parent || err ) {
free( path_basename );
return err;
}
if( parent->ftype != FTYPE_DIR ) {
fs_entry_unlock( parent );
free( path_basename );
return err;
}
// get the child
struct fs_entry* fent = fs_entry_set_find_name( parent->children, path_basename );
free( path_basename );
if( fent == NULL ) {
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -ENOENT;
}
fs_entry_wlock( fent );
bool local = FS_ENTRY_LOCAL( core, fent );
int64_t version = fent->version;
if( check_file_id_and_coordinator_id ) {
if( fent->file_id != file_id ) {
SG_error("Remote unlink to file %s ID %" PRIX64 ", expected %" PRIX64 "\n", path, file_id, fent->file_id );
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -ESTALE;
}
if( fent->coordinator != coordinator_id ) {
SG_error("Remote unlink to file %s coordinator %" PRIu64 ", expected %" PRIu64 "\n", path, coordinator_id, fent->coordinator );
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -ESTALE;
}
}
if( known_version > 0 && fent->version > 0 && fent->version != known_version ) {
SG_error("Remote unlink to file %s version %" PRId64 ", expected %" PRId64 "\n", path, known_version, fent->version );
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return -ESTALE;
}
// make sure the manifest is fresh, so we delete every block
// only need to worry about this if file has > 0 size
if( fent->size > 0 ) {
// try to get it
err = fs_entry_revalidate_manifest( core, path, fent );
if( err != 0 ) {
SG_error( "fs_entry_revalidate_manifest(%s) rc = %d\n", path, err );
if( err == -ENOENT ) {
// continue without a manifest
no_manifest = true;
SG_error("WARN: no manifest found for %s %" PRIX64 ". Assuming data is already vacuumed.\n", path, fent->file_id );
}
else {
// some other problem
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return err;
}
}
}
// tell the driver we're deleting
int driver_rc = driver_delete_file( core, core->closure, path, fent );
if( driver_rc != 0 ) {
SG_error("driver_delete_file(%s %" PRIX64 ") rc = %d\n", path, fent->file_id, driver_rc );
fs_entry_unlock( fent );
fs_entry_unlock( parent );
return driver_rc;
}
rc = 0;
if( !local ) {
// this is someone else's file; tell them to unlink
Serialization::WriteMsg* detach_request = new Serialization::WriteMsg();
fs_entry_init_write_message( detach_request, core, Serialization::WriteMsg::DETACH );
fs_entry_prepare_detach_message( detach_request, path, fent, version );
Serialization::WriteMsg* detach_ack = new Serialization::WriteMsg();
// send the write message, or become the coordinator
rc = fs_entry_send_write_or_coordinate( core, path, fent, detach_request, detach_ack );
if( rc < 0 ) {
SG_error( "fs_entry_send_write_or_coordinate(%s) rc = %d\n", path, rc );
}
else if( rc == 0 ) {
// successfully sent
if( detach_ack->type() != Serialization::WriteMsg::ACCEPTED ) {
if( detach_ack->type() == Serialization::WriteMsg::ERROR ) {
// could not detach on the remote end
SG_error( "remote unlink error = %d (%s)\n", detach_ack->errorcode(), detach_ack->errortxt().c_str() );
rc = detach_ack->errorcode();
}
else {
// unknown message
SG_error( "remote unlink invalid message %d\n", detach_ack->type() );
rc = -EIO;
}
}
}
else {
// we're now the coordinator.
local = true;
}
delete detach_ack;
delete detach_request;
}
if( local ) {
// we're responsible for this file
// mark the file as deleted, so it won't show up again in any listing
fent->deletion_in_progress = true;
// safe to unlock parent--it won't be empty (in a rmdir-able sense) until fent is fully garbage-collected, but fent won't be listed either
fs_entry_unlock( parent );
// garbage-collect, then unlink on the MS. Loop this until we succeed in unlinking on the MS (which can only happen
// once all of fent's data has been garbage-collected).
while( true ) {
if( !no_manifest ) {
// if we got the latest manifest, garbage-collect all writes on the file
rc = fs_entry_vacuumer_file( core, path, fent );
if( rc != 0 ) {
SG_error("fs_entry_vacuumer_vacuum_file( %s %" PRIX64 " ) rc = %d\n", path, fent->file_id, rc );
// failed to garbage-collect...need to un-delete fent
fent->deletion_in_progress = false;
fs_entry_unlock( fent );
return -EREMOTEIO;
}
}
// tell the metadata server we just unlinked
// preserve the entry information so we can issue a deletion
struct md_entry ent;
fs_entry_to_md_entry( core, &ent, fent, parent->file_id, parent->name );
rc = ms_client_delete( core->ms, &ent );
md_entry_free( &ent );
if( rc != 0 ) {
SG_error( "ms_client_delete(%s) rc = %d\n", path, rc );
if( rc == -EAGAIN ) {
if( !no_manifest ) {
// try vacuuming again--some write got added in between our garbage-collection and our unlink request
rc = 0;
continue;
}
else {
// there are un-garbage-collected writes, but we have no manifest, so we can't vacuum in order to proceed with the delete.
SG_error("MEMORY LEAK DETECTED: No manifest for %" PRIX64 " available; unable to vacuum!\n", fent->file_id );
// failed to garbage-collect...need to un-delete fent
fent->deletion_in_progress = false;
fs_entry_unlock( fent );
return -EUCLEAN;
}
}
else {
// something more serious
rc = -EREMOTEIO;
fent->deletion_in_progress = false;
fs_entry_unlock( fent );
return rc;
}
}
else {
// success!
break;
}
}
// re-lock the parent--it's guaranteed to exist, since it's not empty
fs_entry_wlock( parent );
// unlock fent--we're done with it
fs_entry_unlock( fent );
// detatch fent from parent
rc = fs_entry_detach_lowlevel( core, parent, fent );
if( rc != 0 ) {
SG_error("fs_entry_detach_lowlevel(%" PRIX64 ") rc = %d\n", fent->file_id, rc );
fs_entry_unlock( parent );
return rc;
}
fs_entry_unlock( parent );
}
return rc;
}
// make a node (regular files only at this time)
int fs_entry_mknod( struct fs_core* core, char const* path, mode_t mode, dev_t dev, uint64_t user, uint64_t vol ) {
// only regular files at this time...
if( ! ( S_ISREG( mode ) || S_ISFIFO( mode ) ) ) {
return -ENOTSUP;
}
// revalidate this path
int rc = fs_entry_revalidate_path( core, path );
if( rc != 0 && rc != -ENOENT ) {
// consistency cannot be guaranteed
SG_error("fs_entry_revalidate_path(%s) rc = %d\n", path, rc );
return rc;
}
int err = 0;
// get the parent directory and lock it
char* path_dirname = md_dirname( path, NULL );
struct fs_entry* parent = fs_entry_resolve_path( core, path_dirname, user, vol, true, &err );
free( path_dirname );
if( !IS_DIR_READABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// not searchable
fs_entry_unlock( parent );
return -EACCES;
}
if( !IS_WRITEABLE( parent->mode, parent->owner, parent->volume, user, vol ) ) {
// not writeable
fs_entry_unlock( parent );
return -EACCES;
}
uint64_t parent_id = parent->file_id;
char* parent_name = strdup( parent->name );
char* path_basename = md_basename( path, NULL );
// make sure it doesn't exist already (or isn't in the process of being deleted, since we might have to re-create it if deleting it fails)
if( fs_entry_set_find_name( parent->children, path_basename ) != NULL ) {
free( path_basename );
fs_entry_unlock( parent );
free( parent_name );
return -EEXIST;
}
struct fs_entry* child = (struct fs_entry*)calloc( sizeof(struct fs_entry), 1 );
struct timespec ts;
clock_gettime( CLOCK_REALTIME, &ts );
int mmode = 0;
if (S_ISFIFO(mode)) {
mmode = ( mode & 0777 ) | S_IFIFO;
err = fs_entry_init_fifo( core, child, path_basename, 0, fs_entry_next_file_version(), user, core->gateway, vol, mmode, 0, ts.tv_sec, ts.tv_nsec, 0, 0 );
}
if (S_ISREG(mode)) {
mmode = ( mode & 0777 );
err = fs_entry_init_file( core, child, path_basename, 0, fs_entry_next_file_version(), user, core->gateway, vol, mmode, 0, ts.tv_sec, ts.tv_nsec, 0, 0 );
}
if( err == 0 ) {
// mark it as created in this session
child->created_in_session = true;
// we're creating, so this manifest is initialized (to zero blocks)
child->manifest->initialize_empty( child->version );
fs_entry_wlock( child );
// call the driver
err = driver_create_file( core, core->closure, path, child );
if( err != 0 ) {
// undo
SG_error("driver_create_file(%s) rc = %d\n", path, err );
child->open_count = 0;
fs_entry_unlock( child );
fs_entry_destroy( child, false );
free( child );
}
else {
// attach the file
fs_entry_attach_lowlevel( core, parent, child );
struct md_entry data;
fs_entry_to_md_entry( core, &data, child, parent_id, parent_name );
// create the child on the MS, obtaining its file ID and write nonce
err = ms_client_create( core->ms, &child->file_id, &child->write_nonce, &data );
md_entry_free( &data );
if( err != 0 ) {
SG_error( "ms_client_create(%s) rc = %d\n", path, err );
err = -EREMOTEIO;
child->open_count = 0;
fs_entry_unlock( child );
fs_entry_detach_lowlevel( core, parent, child );
free( child );
}
else {
fs_entry_unlock( child );
}
}
}
fs_entry_unlock( parent );
free( parent_name );
free( path_basename );
return err;
}
struct fs_dir_entry* d_ent = NULL;
// handle . and .. separately--we only want to lock children (not the current or parent directory)
if( fent_name_hash == fs_entry_name_hash( "." ) ) {
d_ent = SG_CALLOC( struct fs_dir_entry, 1 );
d_ent->ftype = FTYPE_DIR;
fs_entry_to_md_entry( core, &d_ent->data, dent, parent_id, parent_name );
free( d_ent->data.name );
d_ent->data.name = strdup(".");
}
else if( fent_name_hash == fs_entry_name_hash( ".." ) ) {
d_ent = SG_CALLOC( struct fs_dir_entry, 1 );
d_ent->ftype = FTYPE_DIR;
char* parent_path = md_dirname( fs_path, NULL );
if( fent != dent ) {
fs_entry_to_md_entry( core, &d_ent->data, parent_path, SG_SYS_USER, dent->volume );
}
else {
fs_entry_to_md_entry( core, &d_ent->data, dent, parent_id, parent_name ); // this is /
}
free( parent_path );
free( d_ent->data.name );
d_ent->data.name = strdup("..");
}
else {
if( fent != dent && fs_entry_rlock( fent ) != 0 ) {