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eventfs.c
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eventfs.c
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/*
eventfs: a self-cleaning filesystem for event queues.
Copyright (C) 2015 Jude Nelson
This program is dual-licensed: you can redistribute it and/or modify
it under the terms of the GNU General Public License version 3 or later as
published by the Free Software Foundation. For the terms of this
license, see LICENSE.LGPLv3+ or <http://www.gnu.org/licenses/>.
You are free to use this program under the terms of the GNU General
Public License, 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.
Alternatively, you are free to use this program under the terms of the
Internet Software Consortium License, but WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
For the terms of this license, see LICENSE.ISC or
<http://www.isc.org/downloads/software-support-policy/isc-license/>.
*/
#include "eventfs.h"
// command-line options
struct eventfs_opts {
char* config_path;
};
// try to prune dead directories every REAP_FREQUENCY mkdir's
#define REAP_FREQUENCY 10
int g_mkdir_count = 0;
// locks on the quota sets
int eventfs_quota_rlock( struct eventfs_state* eventfs ) {
return pthread_rwlock_rdlock( &eventfs->quota_lock );
}
int eventfs_quota_wlock( struct eventfs_state* eventfs ) {
return pthread_rwlock_wrlock( &eventfs->quota_lock );
}
int eventfs_quota_unlock( struct eventfs_state* eventfs ) {
return pthread_rwlock_unlock( &eventfs->quota_lock );
}
// create a eventfs file
// return 0 on success
// return -ENOMEM on OOM
// return negative on failure to initialize the inode
int eventfs_create( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, mode_t mode, void** inode_data, void** handle_data ) {
eventfs_debug("eventfs_create(%s) from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
int rc = 0;
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
// NOTE: parent will be write-locked
struct fskit_entry* parent = fskit_route_metadata_get_parent( route_metadata );
struct eventfs_dir_inode* parent_inode = NULL;
struct eventfs_file_inode* inode = NULL;
char name[FSKIT_FILESYSTEM_NAMEMAX+1];
memset( name, 0, FSKIT_FILESYSTEM_NAMEMAX + 1 );
pid_t calling_tid = fskit_fuse_get_pid();
uid_t calling_uid = fskit_fuse_get_uid( eventfs->fuse_state );
gid_t calling_gid = fskit_fuse_get_gid( eventfs->fuse_state );
uint64_t file_quota_user = eventfs->config.default_file_quota;
uint64_t dir_size_quota = eventfs->config.default_files_per_dir_quota;
uint64_t file_quota_group = eventfs->config.default_file_quota;
uint64_t num_files_user = 0;
uint64_t num_files_group = 0;
uint64_t num_dir_children = 0;
uid_t parent_owner = 0;
gid_t parent_group = 0;
bool unknown_user = false;
bool unknown_group = false;
eventfs_usage* new_user_usage = NULL;
eventfs_usage* new_group_usage = NULL;
num_dir_children = fskit_entry_get_num_children( parent );
parent_owner = fskit_entry_get_owner( parent );
parent_group = fskit_entry_get_group( parent );
// look up quotas
eventfs_quota_rlock( eventfs );
if( eventfs_quota_lookup( eventfs->user_quotas, parent_owner ) != NULL ) {
dir_size_quota = eventfs_quota_get_max_files_per_dir( eventfs->user_quotas, parent_owner );
}
else if( eventfs_quota_lookup( eventfs->group_quotas, parent_group ) != NULL ) {
dir_size_quota = eventfs_quota_get_max_files_per_dir( eventfs->group_quotas, parent_group );
}
if( eventfs_quota_lookup( eventfs->user_quotas, calling_uid ) != NULL ) {
file_quota_user = eventfs_quota_get_max_files( eventfs->user_quotas, calling_uid );
}
if( eventfs_usage_lookup( eventfs->user_usages, calling_uid ) != NULL ) {
num_files_user = eventfs_usage_get_num_files( eventfs->user_usages, calling_uid );
}
else {
unknown_user = true;
}
if( eventfs_quota_lookup( eventfs->group_quotas, calling_gid ) != NULL ) {
file_quota_group = eventfs_quota_get_max_files( eventfs->group_quotas, calling_gid );
}
if( eventfs_usage_lookup( eventfs->group_usages, calling_gid ) != NULL ) {
num_files_group = eventfs_usage_get_num_files( eventfs->group_usages, calling_gid );
}
else {
unknown_group = true;
}
eventfs_quota_unlock( eventfs );
// check quotas
if( dir_size_quota + 2 <= num_dir_children ) {
printf("User %d has per-directory quota of %d; using %d\n", calling_uid, (int)dir_size_quota, (int)(num_dir_children) );
// directory has gotten too big
return -EDQUOT;
}
if( file_quota_user <= num_files_user ) {
printf("User %d has file quota of %d; using %d\n", calling_uid, (int)file_quota_user, (int)(num_files_user) );
// user has too many files
// BUT! Can we reap some directories?
rc = eventfs_deferred_reap( eventfs );
if( rc != 0 ) {
eventfs_error("eventfs_deferred_reap rc = %d\n", rc );
rc = 0;
}
return -EDQUOT;
}
if( file_quota_group <= num_files_group ) {
printf("Group %d has file quota of %d; using %d\n", calling_gid, (int)file_quota_group, (int)(num_files_group) );
// group has too many files
// BUT! Can we reap some directories?
rc = eventfs_deferred_reap( eventfs );
if( rc != 0 ) {
eventfs_error("eventfs_deferred_reap rc = %d\n", rc );
rc = 0;
}
return -EDQUOT;
}
// set up new usages, if we need to
if( unknown_user ) {
new_user_usage = EVENTFS_CALLOC( eventfs_usage, 1 );
if( new_user_usage == NULL ) {
return -ENOMEM;
}
}
if( unknown_group ) {
new_group_usage = EVENTFS_CALLOC( eventfs_usage, 1 );
if( new_group_usage == NULL ) {
eventfs_safe_free( new_user_usage );
return -ENOMEM;
}
}
// set up inode
inode = EVENTFS_CALLOC( struct eventfs_file_inode, 1 );
if( inode == NULL ) {
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
return -ENOMEM;
}
rc = eventfs_file_inode_init( inode );
if( rc != 0 ) {
// phantom process?
eventfs_safe_free( inode );
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
return rc;
}
// attach to parent (will already be write-locked)
parent_inode = (struct eventfs_dir_inode*)fskit_entry_get_user_data( parent );
if( parent_inode == NULL ) {
eventfs_error("BUG: parent %p has no inode data!\n", parent );
eventfs_file_inode_free( inode );
eventfs_safe_free( inode );
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
return -EIO;
}
rc = eventfs_dir_inode_append( core, parent_inode, parent, fskit_route_metadata_get_name( route_metadata ) );
if( rc != 0 ) {
// failed
eventfs_file_inode_free( inode );
eventfs_safe_free( inode );
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
return rc;
}
*inode_data = (void*)inode;
// update usages
if( !unknown_user ) {
eventfs_usage_change_num_files( eventfs->user_usages, calling_uid, 1 );
}
else {
eventfs_usage_init( new_user_usage, calling_uid, 1, 0, 0 );
eventfs_usage_put( &eventfs->user_usages, new_user_usage );
}
if( !unknown_group ) {
eventfs_usage_change_num_files( eventfs->group_usages, calling_gid, 1 );
}
else {
eventfs_usage_init( new_group_usage, calling_gid, 1, 0, 0 );
eventfs_usage_put( &eventfs->group_usages, new_group_usage );
}
return rc;
}
// create a directory
// in eventfs, there can only be one "layer" of directories.
// return 0 on success, and set *inode_data
// return -ENOMEM on OOM
// return negative on failure to initialize the inode
int eventfs_mkdir( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* dent, mode_t mode, void** inode_data ) {
eventfs_debug("eventfs_mkdir(%s) from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
int rc = 0;
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
struct fskit_entry* head = NULL;
struct fskit_entry* tail = NULL;
char* path = fskit_route_metadata_get_path( route_metadata );
if( fskit_depth( path ) > 1 ) {
// not allowed
return -EPERM;
}
// NOTE: parent will be write-locked
struct fskit_entry* parent = fskit_route_metadata_get_parent( route_metadata );
struct eventfs_dir_inode* parent_inode = NULL;
struct eventfs_dir_inode* inode = NULL;
char name[FSKIT_FILESYSTEM_NAMEMAX+1];
memset( name, 0, FSKIT_FILESYSTEM_NAMEMAX + 1 );
pid_t calling_tid = fskit_fuse_get_pid();
uid_t calling_uid = fskit_fuse_get_uid( eventfs->fuse_state );
gid_t calling_gid = fskit_fuse_get_gid( eventfs->fuse_state );
uint64_t dir_quota_user = eventfs->config.default_dir_quota;
uint64_t dir_quota_group = eventfs->config.default_dir_quota;
uint64_t num_dirs_user = 0;
uint64_t num_dirs_group = 0;
bool unknown_user = false;
bool unknown_group = false;
eventfs_usage* new_user_usage = NULL;
eventfs_usage* new_group_usage = NULL;
// look up quotas
eventfs_quota_rlock( eventfs );
if( eventfs_quota_lookup( eventfs->user_quotas, calling_uid ) != NULL ) {
dir_quota_user = eventfs_quota_get_max_dirs( eventfs->user_quotas, calling_uid );
}
if( eventfs_usage_lookup( eventfs->user_usages, calling_uid ) != NULL ) {
num_dirs_user = eventfs_usage_get_num_dirs( eventfs->user_usages, calling_uid );
}
else {
unknown_user = true;
}
if( eventfs_quota_lookup( eventfs->group_quotas, calling_gid ) != NULL ) {
dir_quota_group = eventfs_quota_get_max_dirs( eventfs->group_quotas, calling_gid );
}
else if( eventfs_usage_lookup( eventfs->group_usages, calling_gid ) != NULL ) {
num_dirs_group = eventfs_usage_get_num_dirs( eventfs->group_usages, calling_gid );
}
else {
unknown_group = true;
}
eventfs_quota_unlock( eventfs );
// check quotas
if( dir_quota_user <= num_dirs_user ) {
// user has too many dirs
// BUT! Can we reap some of them?
rc = eventfs_deferred_reap( eventfs );
if( rc != 0 ) {
eventfs_error("eventfs_deferred_reap rc = %d\n", rc );
rc = 0;
}
return -EDQUOT;
}
if( dir_quota_group <= num_dirs_group ) {
// group has too many dirs
// BUT! Can we reap some of them?
rc = eventfs_deferred_reap( eventfs );
if( rc != 0 ) {
eventfs_error("eventfs_deferred_reap rc = %d\n", rc );
rc = 0;
}
return -EDQUOT;
}
// set up new usages, if we need to
if( unknown_user ) {
new_user_usage = EVENTFS_CALLOC( eventfs_usage, 1 );
if( new_user_usage == NULL ) {
return -ENOMEM;
}
}
if( unknown_group ) {
new_group_usage = EVENTFS_CALLOC( eventfs_usage, 1 );
if( new_group_usage == NULL ) {
eventfs_safe_free( new_user_usage );
return -ENOMEM;
}
}
inode = EVENTFS_CALLOC( struct eventfs_dir_inode, 1 );
if( inode == NULL ) {
// OOM
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
return -ENOMEM;
}
// set up directory state
rc = eventfs_dir_inode_init( inode, calling_tid, EVENTFS_VERIFY_DEFAULT );
if( rc != 0 ) {
// phantom process?
eventfs_safe_free( new_user_usage );
eventfs_safe_free( new_group_usage );
eventfs_safe_free( inode );
return rc;
}
*inode_data = (void*)inode;
int cur_mkdir_count = __sync_add_and_fetch( &g_mkdir_count, 1 );
if( cur_mkdir_count == REAP_FREQUENCY ) {
cur_mkdir_count = __sync_sub_and_fetch( &g_mkdir_count, REAP_FREQUENCY );
if( cur_mkdir_count < REAP_FREQUENCY ) {
// Either the process that decremented g_mkdir_count gets this far,
// or it doesn't. If it doesn't--that is, g_mkdir_count gets incremented
// more than REAP_FREQUENCY times between this process's __sync_add_and_fetch
// and its subsequent __sync_sub_and_fetch, then it means at least one
// other process will have observed cur_mkdir_count == REAP_FREQUENCY,
// and exactly one of them will observe cur_mkdir_count < REAP_FREQUENCY.
// The point is, a high volume of mkdirs should not starve the reaper thread.
eventfs_debug("%s", "Reap dead directories\n" );
rc = eventfs_deferred_reap( eventfs );
if( rc != 0 ) {
eventfs_error("eventfs_deferred_reap rc = %d\n", rc );
rc = 0;
}
}
}
// update usages
if( new_user_usage == NULL ) {
eventfs_usage_change_num_dirs( eventfs->user_usages, calling_uid, 1 );
}
else {
eventfs_usage_init( new_user_usage, calling_uid, 0, 1, 0 );
eventfs_usage_put( &eventfs->user_usages, new_user_usage );
}
if( new_group_usage == NULL ) {
eventfs_usage_change_num_dirs( eventfs->group_usages, calling_gid, 1 );
}
else {
eventfs_usage_init( new_group_usage, calling_gid, 0, 1, 0 );
eventfs_usage_put( &eventfs->group_usages, new_group_usage );
}
// success!
return rc;
}
// read a file
// return the number of bytes read on success
// return 0 on EOF
// return -ENOSYS if the inode is not initialize (should *never* happen)
int eventfs_read( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, char* buf, size_t buflen, off_t offset, void* handle_data ) {
eventfs_debug("eventfs_read(%s) from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
struct eventfs_file_inode* inode = (struct eventfs_file_inode*)fskit_entry_get_user_data( fent );
int num_read = 0;
if( inode == NULL ) {
return -ENOSYS;
}
if( offset >= inode->size ) {
return 0;
}
// copy data out, if we have any
if( inode->contents != NULL ) {
num_read = buflen;
if( (unsigned)(offset + buflen) >= inode->size ) {
num_read = inode->size - offset;
if( num_read < 0 ) {
num_read = 0;
}
}
}
if( num_read > 0 ) {
memcpy( buf, inode->contents + offset, num_read );
}
return num_read;
}
// write to a file
// return the number of bytes written, and expand the file in RAM if we write off the edge.
// return -ENOSYS if for some reason we don't have an inode (should *never* happen)
// return -ENOMEM on OOM
// NOTE: we use FSKIT_INODE_SEQUENTIAL, so fent will be write-locked
int eventfs_write( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, char* buf, size_t buflen, off_t offset, void* handle_data ) {
eventfs_debug("eventfs_write(%s) from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
struct eventfs_file_inode* inode = (struct eventfs_file_inode*)fskit_entry_get_user_data( fent );
size_t new_contents_len = inode->contents_len;
if( inode == NULL ) {
return -ENOSYS;
}
off_t cur_size = inode->size;
int64_t add_to_usage = (cur_size >= offset + buflen ? 0 : (offset + buflen) - cur_size);
pid_t calling_tid = fskit_fuse_get_pid();
uid_t owner_uid = fskit_entry_get_owner( fent );
gid_t owner_gid = fskit_entry_get_group( fent );
uint64_t bytes_quota_user = eventfs->config.default_bytes_quota;
uint64_t bytes_quota_group = eventfs->config.default_bytes_quota;
uint64_t num_bytes_user = 0;
uint64_t num_bytes_group = 0;
bool unknown_user = false;
bool unknown_group = false;
// look up quotas
eventfs_quota_rlock( eventfs );
if( eventfs_quota_lookup( eventfs->user_quotas, owner_uid ) != NULL ) {
bytes_quota_user = eventfs_quota_get_max_bytes( eventfs->user_quotas, owner_uid );
}
if( eventfs_usage_lookup( eventfs->user_usages, owner_uid ) != NULL ) {
num_bytes_user = eventfs_usage_get_num_bytes( eventfs->user_usages, owner_uid );
}
else {
unknown_user = true;
}
if( eventfs_quota_lookup( eventfs->group_quotas, owner_gid ) != NULL ) {
bytes_quota_group = eventfs_quota_get_max_bytes( eventfs->group_quotas, owner_gid );
}
if( eventfs_usage_lookup( eventfs->group_usages, owner_gid ) != NULL ) {
num_bytes_group = eventfs_usage_get_num_bytes( eventfs->group_usages, owner_gid );
}
else {
unknown_group = true;
}
eventfs_quota_unlock( eventfs );
if( unknown_user && unknown_group ) {
// something weird is going on
return -EDQUOT;
}
// check quotas
if( bytes_quota_user <= num_bytes_user + add_to_usage ) {
printf("User %d has byte quota of %d; using %d (%d)\n", owner_uid, (int)bytes_quota_user, (int)(num_bytes_user + add_to_usage), (int)add_to_usage );
// user has too many bytes
return -EDQUOT;
}
if( bytes_quota_group <= num_bytes_group + add_to_usage ) {
// group has too many bytes
printf("Group %d has byte quota of %d; using %d (%d)\n", owner_gid, (int)bytes_quota_user, (int)(num_bytes_user + add_to_usage), (int)add_to_usage );
return -EDQUOT;
}
if( new_contents_len == 0 ) {
new_contents_len = 1;
}
// expand contents?
while( offset + buflen > new_contents_len ) {
new_contents_len *= 2;
}
if( new_contents_len > inode->contents_len ) {
// expand
char* tmp = (char*)realloc( inode->contents, new_contents_len );
if( tmp == NULL ) {
return -ENOMEM;
}
inode->contents = tmp;
memset( inode->contents + inode->contents_len, 0, new_contents_len - inode->contents_len );
inode->contents_len = new_contents_len;
}
// write in
memcpy( inode->contents + offset, buf, buflen );
// expand size?
if( (unsigned)(offset + buflen) > inode->size ) {
inode->size = offset + buflen;
}
// update usages
if( !unknown_user ) {
eventfs_usage_change_num_bytes( eventfs->user_usages, owner_uid, add_to_usage );
}
if( !unknown_group ) {
eventfs_usage_change_num_bytes( eventfs->group_usages, owner_gid, add_to_usage );
}
return buflen;
}
// truncate a file
// return 0 on success, and reset the size and RAM buffer
// return -ENOMEM on OOM
// return -ENOSYS if for some reason we don't have an inode (should *never* happen)
// use under the FSKIT_INODE_SEQUENTIAL consistency discipline--the entry will be write-locked when we call this method.
int eventfs_truncate( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, off_t new_size, void* inode_data ) {
eventfs_debug("eventfs_truncate(%s) from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
struct eventfs_file_inode* inode = (struct eventfs_file_inode*)fskit_entry_get_user_data( fent );
size_t new_contents_len = inode->contents_len;
if( inode == NULL ) {
return -ENOSYS;
}
off_t cur_size = inode->size;
int64_t add_to_usage = new_size - cur_size;
pid_t calling_tid = fskit_fuse_get_pid();
uid_t owner_uid = fskit_entry_get_owner( fent );
gid_t owner_gid = fskit_entry_get_group( fent );
uint64_t bytes_quota_user = eventfs->config.default_bytes_quota;
uint64_t bytes_quota_group = eventfs->config.default_bytes_quota;
uint64_t num_bytes_user = 0;
uint64_t num_bytes_group = 0;
bool unknown_user = false;
bool unknown_group = false;
// look up quotas
eventfs_quota_rlock( eventfs );
if( eventfs_quota_lookup( eventfs->user_quotas, owner_uid ) != NULL ) {
bytes_quota_user = eventfs_quota_get_max_bytes( eventfs->user_quotas, owner_uid );
}
if( eventfs_usage_lookup( eventfs->user_usages, owner_uid ) != NULL ) {
num_bytes_user = eventfs_usage_get_num_bytes( eventfs->user_usages, owner_uid );
}
else {
unknown_user = true;
}
if( eventfs_quota_lookup( eventfs->group_quotas, owner_gid ) != NULL ) {
bytes_quota_group = eventfs_quota_get_max_bytes( eventfs->group_quotas, owner_gid );
}
if( eventfs_usage_lookup( eventfs->group_usages, owner_gid ) != NULL ) {
num_bytes_group = eventfs_usage_get_num_bytes( eventfs->group_usages, owner_gid );
}
else {
unknown_group = true;
}
eventfs_quota_unlock( eventfs );
if( unknown_user && unknown_group ) {
// something weird is going on
return -EDQUOT;
}
// check quotas
if( bytes_quota_user <= num_bytes_user + add_to_usage ) {
// user has too many bytes
return -EDQUOT;
}
if( bytes_quota_group <= num_bytes_group + add_to_usage ) {
// group has too many bytes
return -EDQUOT;
}
// expand?
if( (unsigned)new_size >= inode->contents_len ) {
if( new_contents_len == 0 ) {
new_contents_len = 1;
}
while( (unsigned)new_size > new_contents_len ) {
new_contents_len *= 2;
}
char* tmp = (char*)realloc( inode->contents, new_contents_len );
if( tmp == NULL ) {
return -ENOMEM;
}
inode->contents = tmp;
memset( inode->contents + inode->contents_len, 0, new_contents_len - inode->contents_len );
inode->contents_len = new_contents_len;
}
else {
memset( inode->contents + new_size, 0, inode->contents_len - new_size );
}
// new size
inode->size = new_size;
// update usages
if( !unknown_user ) {
eventfs_usage_change_num_bytes( eventfs->user_usages, owner_uid, add_to_usage );
}
if( !unknown_group ) {
eventfs_usage_change_num_files( eventfs->group_usages, owner_gid, add_to_usage );
}
return 0;
}
// remove a file: either we're destroying it, or unlinking it.
// atomically removes the inode from the directory, *and* updates the head and/or tail pointers to point to the new deque's head and tail
// return 0 on success, and free up the given inode_data
// return -ENOENT if the parent dir no longer exists
// NOTE: fent cannot be locked.
int eventfs_remove_file( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, void* inode_data, bool destroy ) {
eventfs_debug("eventfs_remove_file('%s', destroy=%d) from %d\n", fskit_route_metadata_get_path( route_metadata ), destroy, fskit_fuse_get_pid() );
int rc = 0;
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
struct eventfs_file_inode* inode = (struct eventfs_file_inode*)inode_data;
struct fskit_entry* parent = fskit_route_metadata_get_parent( route_metadata );
struct eventfs_dir_inode* dir_inode = NULL;
struct eventfs_file_inode* old_file = NULL;
char const* path = fskit_route_metadata_get_path( route_metadata );
char* dir_path = NULL;
char name[FSKIT_FILESYSTEM_NAMEMAX+1];
uid_t owner_uid = fskit_entry_get_owner( fent );
gid_t owner_gid = fskit_entry_get_group( fent );
off_t cur_size = 0;
int type = fskit_entry_get_type( fent );
if( inode != NULL ) {
cur_size = inode->size;
}
memset( name, 0, FSKIT_FILESYSTEM_NAMEMAX+1 );
fskit_basename( path, name );
if( parent != NULL ) {
// parent is not NULL--we're detaching
// NOTE: parent is guaranteed to be write-locked
dir_inode = (struct eventfs_dir_inode*)fskit_entry_get_user_data( parent );
if( dir_inode == NULL ) {
eventfs_error("BUG: no inode data for %p\n", parent );
return -EIO;
}
if( !dir_inode->deleted ) {
// not reaped by us
// get parent path
dir_path = fskit_dirname( fskit_route_metadata_get_path( route_metadata ), NULL );
if( dir_path == NULL ) {
return -ENOMEM;
}
if( !destroy ) {
// only detaching...
if( fent == dir_inode->fent_head ) {
// detaching head symlink. Recreate and retarget, or detach if empty.
// also, detach the associated file the head points to.
rc = eventfs_dir_inode_pophead( core, dir_path, dir_inode, parent );
}
else if( fent == dir_inode->fent_tail ) {
// detach tail symlink. Recreate and retarget, or detach if empty.
// also, deatch the associated file the tail points to.
rc = eventfs_dir_inode_poptail( core, dir_path, dir_inode, parent );
}
else {
// detach a file in the middle
rc = eventfs_dir_inode_remove( core, dir_path, dir_inode, parent, name );
}
}
else {
// freeing a fully-detached inode.
// we can ignore the head and tail symlinks.
// free a file inode's internal data, though.
if( !eventfs_dir_inode_is_empty( dir_inode ) && fent != dir_inode->fent_head && fent != dir_inode->fent_tail ) {
fskit_entry_rlock( fent );
old_file = (struct eventfs_file_inode*)fskit_entry_get_user_data( fent );
fskit_entry_unlock( fent );
// deleting a file in the middle
eventfs_dir_inode_remove( core, dir_path, dir_inode, parent, name );
if( old_file != NULL ) {
eventfs_file_inode_free( old_file );
eventfs_safe_free( old_file );
}
}
}
eventfs_safe_free( dir_path );
}
else {
eventfs_debug("Parent of '%s' already reaped\n", fskit_route_metadata_get_path( route_metadata ));
}
}
else if( destroy ) {
// this entry was already detached; we're just getting around to freeing it.
eventfs_debug("reclaim %s\n", path );
if( inode != NULL ) {
eventfs_file_inode_free( inode );
eventfs_safe_free( inode );
}
}
// debit usages
if( type == FSKIT_ENTRY_TYPE_FILE ) {
eventfs_quota_rlock( eventfs );
if( eventfs_usage_lookup( eventfs->user_usages, owner_uid ) != NULL ) {
// reduce user usage
if( destroy ) {
eventfs_usage_change_num_bytes( eventfs->user_usages, owner_uid, -cur_size );
}
eventfs_usage_change_num_files( eventfs->user_usages, owner_uid, -1 );
}
if( eventfs_usage_lookup( eventfs->group_usages, owner_gid ) != NULL ) {
if( destroy ) {
eventfs_usage_change_num_bytes( eventfs->group_usages, owner_gid, -cur_size );
}
eventfs_usage_change_num_files( eventfs->group_usages, owner_gid, -1 );
}
eventfs_quota_unlock( eventfs );
}
return rc;
}
// remove a directory
// return 0 on success, and free up the given inode data
// return -ENOENT if the directory no longer exists.
int eventfs_destroy_dir( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* dent, void* inode_data ) {
eventfs_debug("eventfs_destroy_dir('%s') from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );
struct eventfs_dir_inode* inode = (struct eventfs_dir_inode*)inode_data;
uid_t owner_uid = fskit_entry_get_owner( dent );
gid_t owner_gid = fskit_entry_get_group( dent );
// blow away the inode
if( inode != NULL ) {
eventfs_dir_inode_free( core, inode );
eventfs_safe_free( inode );
// be *sure* it's gone
fskit_entry_set_user_data( dent, NULL );
}
// debit usages
eventfs_quota_rlock( eventfs );
if( eventfs_usage_lookup( eventfs->user_usages, owner_uid ) != NULL ) {
// reduce user usage
eventfs_usage_change_num_dirs( eventfs->user_usages, owner_uid, -1 );
}
if( eventfs_usage_lookup( eventfs->group_usages, owner_gid ) != NULL ) {
eventfs_usage_change_num_dirs( eventfs->group_usages, owner_gid, -1 );
}
eventfs_quota_unlock( eventfs );
return 0;
}
// destroy a file or directory
// return 0 on success, and free up the inode data
// return -ENONET if the directory no longer eists
int eventfs_destroy( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, void* inode_data ) {
eventfs_debug("eventfs_destroy('%s') from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
fskit_entry_rlock( fent );
int type = fskit_entry_get_type( fent );
fskit_entry_unlock( fent );
if( type == FSKIT_ENTRY_TYPE_DIR ) {
return eventfs_destroy_dir( core, route_metadata, fent, inode_data );
}
else if( type == FSKIT_ENTRY_TYPE_FILE || type == FSKIT_ENTRY_TYPE_LNK ) {
return eventfs_remove_file( core, route_metadata, fent, inode_data, true );
}
else {
// we have no state associated with non-regular-file inodes
return 0;
}
}
// detach a file
// return 0 on success, and free up the inode data
// return -ENONET if the directory no longer eists
int eventfs_detach( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, void* inode_data ) {
eventfs_debug("eventfs_detach('%s') from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
fskit_entry_rlock( fent );
int type = fskit_entry_get_type( fent );
fskit_entry_unlock( fent );
if( type == FSKIT_ENTRY_TYPE_DIR ) {
return 0;
}
else if( type == FSKIT_ENTRY_TYPE_FILE || type == FSKIT_ENTRY_TYPE_LNK ) {
return eventfs_remove_file( core, route_metadata, fent, inode_data, false );
}
else {
// we have no state associated with non-regular-file inodes
return 0;
}
}
// stat an entry.
// for non-root diretories, garbage-collect both it and and its children if the process that created it died.
// return 0 on success
// return -ENOENT if the path does not exist
// return -EIO if the inode is invalid
int eventfs_stat( struct fskit_core* core, struct fskit_route_metadata* route_metadata, struct fskit_entry* fent, struct stat* sb ) {
eventfs_debug("eventfs_stat('%s') from %d\n", fskit_route_metadata_get_path( route_metadata ), fskit_fuse_get_pid() );
int rc = 0;
struct eventfs_state* eventfs = (struct eventfs_state*)fskit_core_get_user_data( core );