Annotation of qemu/block_int.h, revision 1.1.1.17

1.1       root        1: /*
                      2:  * QEMU System Emulator block driver
1.1.1.5   root        3:  *
1.1       root        4:  * Copyright (c) 2003 Fabrice Bellard
1.1.1.5   root        5:  *
1.1       root        6:  * Permission is hereby granted, free of charge, to any person obtaining a copy
                      7:  * of this software and associated documentation files (the "Software"), to deal
                      8:  * in the Software without restriction, including without limitation the rights
                      9:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
                     10:  * copies of the Software, and to permit persons to whom the Software is
                     11:  * furnished to do so, subject to the following conditions:
                     12:  *
                     13:  * The above copyright notice and this permission notice shall be included in
                     14:  * all copies or substantial portions of the Software.
                     15:  *
                     16:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
                     17:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
                     18:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
                     19:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
                     20:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
                     21:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
                     22:  * THE SOFTWARE.
                     23:  */
                     24: #ifndef BLOCK_INT_H
                     25: #define BLOCK_INT_H
                     26: 
1.1.1.5   root       27: #include "block.h"
1.1.1.10  root       28: #include "qemu-option.h"
1.1.1.13  root       29: #include "qemu-queue.h"
1.1.1.16  root       30: #include "qemu-coroutine.h"
                     31: #include "qemu-timer.h"
                     32: #include "qapi-types.h"
1.1.1.5   root       33: 
                     34: #define BLOCK_FLAG_ENCRYPT     1
                     35: #define BLOCK_FLAG_COMPAT6     4
                     36: 
1.1.1.17! root       37: #define BLOCK_IO_LIMIT_READ     0
        !            38: #define BLOCK_IO_LIMIT_WRITE    1
        !            39: #define BLOCK_IO_LIMIT_TOTAL    2
        !            40: 
        !            41: #define BLOCK_IO_SLICE_TIME     100000000
        !            42: #define NANOSECONDS_PER_SECOND  1000000000.0
        !            43: 
1.1.1.10  root       44: #define BLOCK_OPT_SIZE          "size"
                     45: #define BLOCK_OPT_ENCRYPT       "encryption"
                     46: #define BLOCK_OPT_COMPAT6       "compat6"
                     47: #define BLOCK_OPT_BACKING_FILE  "backing_file"
                     48: #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
                     49: #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
1.1.1.14  root       50: #define BLOCK_OPT_TABLE_SIZE    "table_size"
1.1.1.11  root       51: #define BLOCK_OPT_PREALLOC      "preallocation"
1.1.1.15  root       52: #define BLOCK_OPT_SUBFMT        "subformat"
1.1.1.17! root       53: #define BLOCK_OPT_COMPAT_LEVEL  "compat"
        !            54: 
        !            55: typedef struct BdrvTrackedRequest BdrvTrackedRequest;
        !            56: 
        !            57: typedef struct BlockIOLimit {
        !            58:     int64_t bps[3];
        !            59:     int64_t iops[3];
        !            60: } BlockIOLimit;
        !            61: 
        !            62: typedef struct BlockIOBaseValue {
        !            63:     uint64_t bytes[2];
        !            64:     uint64_t ios[2];
        !            65: } BlockIOBaseValue;
        !            66: 
        !            67: typedef struct BlockJob BlockJob;
        !            68: 
        !            69: /**
        !            70:  * BlockJobType:
        !            71:  *
        !            72:  * A class type for block job objects.
        !            73:  */
        !            74: typedef struct BlockJobType {
        !            75:     /** Derived BlockJob struct size */
        !            76:     size_t instance_size;
        !            77: 
        !            78:     /** String describing the operation, part of query-block-jobs QMP API */
        !            79:     const char *job_type;
        !            80: 
        !            81:     /** Optional callback for job types that support setting a speed limit */
        !            82:     void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
        !            83: } BlockJobType;
        !            84: 
        !            85: /**
        !            86:  * BlockJob:
        !            87:  *
        !            88:  * Long-running operation on a BlockDriverState.
        !            89:  */
        !            90: struct BlockJob {
        !            91:     /** The job type, including the job vtable.  */
        !            92:     const BlockJobType *job_type;
        !            93: 
        !            94:     /** The block device on which the job is operating.  */
        !            95:     BlockDriverState *bs;
        !            96: 
        !            97:     /**
        !            98:      * The coroutine that executes the job.  If not NULL, it is
        !            99:      * reentered when busy is false and the job is cancelled.
        !           100:      */
        !           101:     Coroutine *co;
        !           102: 
        !           103:     /**
        !           104:      * Set to true if the job should cancel itself.  The flag must
        !           105:      * always be tested just before toggling the busy flag from false
        !           106:      * to true.  After a job has been cancelled, it should only yield
        !           107:      * if #qemu_aio_wait will ("sooner or later") reenter the coroutine.
        !           108:      */
        !           109:     bool cancelled;
        !           110: 
        !           111:     /**
        !           112:      * Set to false by the job while it is in a quiescent state, where
        !           113:      * no I/O is pending and the job has yielded on any condition
        !           114:      * that is not detected by #qemu_aio_wait, such as a timer.
        !           115:      */
        !           116:     bool busy;
        !           117: 
        !           118:     /** Offset that is published by the query-block-jobs QMP API */
        !           119:     int64_t offset;
        !           120: 
        !           121:     /** Length that is published by the query-block-jobs QMP API */
        !           122:     int64_t len;
        !           123: 
        !           124:     /** Speed that was set with @block_job_set_speed.  */
        !           125:     int64_t speed;
1.1.1.10  root      126: 
1.1.1.17! root      127:     /** The completion function that will be called when the job completes.  */
        !           128:     BlockDriverCompletionFunc *cb;
        !           129: 
        !           130:     /** The opaque value that is passed to the completion function.  */
        !           131:     void *opaque;
        !           132: };
1.1.1.9   root      133: 
1.1       root      134: struct BlockDriver {
                    135:     const char *format_name;
                    136:     int instance_size;
                    137:     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
1.1.1.10  root      138:     int (*bdrv_probe_device)(const char *filename);
1.1.1.13  root      139:     int (*bdrv_open)(BlockDriverState *bs, int flags);
                    140:     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
1.1.1.5   root      141:     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
1.1       root      142:                      uint8_t *buf, int nb_sectors);
1.1.1.5   root      143:     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
1.1       root      144:                       const uint8_t *buf, int nb_sectors);
                    145:     void (*bdrv_close)(BlockDriverState *bs);
1.1.1.17! root      146:     void (*bdrv_rebind)(BlockDriverState *bs);
1.1.1.10  root      147:     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
1.1       root      148:     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
1.1.1.2   root      149:     int (*bdrv_make_empty)(BlockDriverState *bs);
1.1.1.4   root      150:     /* aio */
1.1.1.10  root      151:     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
                    152:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1.1.1.4   root      153:         BlockDriverCompletionFunc *cb, void *opaque);
1.1.1.10  root      154:     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
                    155:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1.1.1.4   root      156:         BlockDriverCompletionFunc *cb, void *opaque);
1.1.1.11  root      157:     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
                    158:         BlockDriverCompletionFunc *cb, void *opaque);
1.1.1.16  root      159:     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
                    160:         int64_t sector_num, int nb_sectors,
                    161:         BlockDriverCompletionFunc *cb, void *opaque);
                    162: 
                    163:     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
                    164:         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
                    165:     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
                    166:         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
1.1.1.17! root      167:     /*
        !           168:      * Efficiently zero a region of the disk image.  Typically an image format
        !           169:      * would use a compact metadata representation to implement this.  This
        !           170:      * function pointer may be NULL and .bdrv_co_writev() will be called
        !           171:      * instead.
        !           172:      */
        !           173:     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
        !           174:         int64_t sector_num, int nb_sectors);
1.1.1.16  root      175:     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
                    176:         int64_t sector_num, int nb_sectors);
1.1.1.17! root      177:     int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
        !           178:         int64_t sector_num, int nb_sectors, int *pnum);
1.1.1.16  root      179: 
                    180:     /*
                    181:      * Invalidate any cached meta-data.
                    182:      */
                    183:     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
                    184: 
                    185:     /*
                    186:      * Flushes all data that was already written to the OS all the way down to
                    187:      * the disk (for example raw-posix calls fsync()).
                    188:      */
                    189:     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
                    190: 
                    191:     /*
                    192:      * Flushes all internal caches to the OS. The data may still sit in a
                    193:      * writeback cache of the host OS, but it will survive a crash of the qemu
                    194:      * process.
                    195:      */
                    196:     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
1.1.1.11  root      197: 
1.1.1.4   root      198:     const char *protocol_name;
                    199:     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
                    200:     int64_t (*bdrv_getlength)(BlockDriverState *bs);
1.1.1.15  root      201:     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
1.1.1.5   root      202:     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
1.1.1.4   root      203:                                  const uint8_t *buf, int nb_sectors);
                    204: 
1.1.1.5   root      205:     int (*bdrv_snapshot_create)(BlockDriverState *bs,
1.1.1.4   root      206:                                 QEMUSnapshotInfo *sn_info);
1.1.1.5   root      207:     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
1.1.1.4   root      208:                               const char *snapshot_id);
                    209:     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
1.1.1.5   root      210:     int (*bdrv_snapshot_list)(BlockDriverState *bs,
1.1.1.4   root      211:                               QEMUSnapshotInfo **psn_info);
1.1.1.14  root      212:     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
                    213:                                   const char *snapshot_name);
1.1.1.4   root      214:     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
                    215: 
1.1.1.10  root      216:     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
                    217:                              int64_t pos, int size);
                    218:     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
                    219:                              int64_t pos, int size);
1.1.1.8   root      220: 
1.1.1.13  root      221:     int (*bdrv_change_backing_file)(BlockDriverState *bs,
                    222:         const char *backing_file, const char *backing_fmt);
                    223: 
1.1.1.4   root      224:     /* removable device specific */
                    225:     int (*bdrv_is_inserted)(BlockDriverState *bs);
                    226:     int (*bdrv_media_changed)(BlockDriverState *bs);
1.1.1.17! root      227:     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
1.1.1.16  root      228:     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
1.1.1.5   root      229: 
                    230:     /* to control generic scsi devices */
                    231:     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
1.1.1.10  root      232:     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
                    233:         unsigned long int req, void *buf,
                    234:         BlockDriverCompletionFunc *cb, void *opaque);
                    235: 
                    236:     /* List of options for creating images, terminated by name == NULL */
                    237:     QEMUOptionParameter *create_options;
                    238: 
                    239: 
1.1.1.13  root      240:     /*
                    241:      * Returns 0 for completed check, -errno for internal errors.
                    242:      * The check results are stored in result.
                    243:      */
                    244:     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
                    245: 
                    246:     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
                    247: 
                    248:     /*
                    249:      * Returns 1 if newly created images are guaranteed to contain only
                    250:      * zeros, 0 otherwise.
                    251:      */
                    252:     int (*bdrv_has_zero_init)(BlockDriverState *bs);
1.1.1.11  root      253: 
1.1.1.13  root      254:     QLIST_ENTRY(BlockDriver) list;
1.1       root      255: };
                    256: 
1.1.1.17! root      257: /*
        !           258:  * Note: the function bdrv_append() copies and swaps contents of
        !           259:  * BlockDriverStates, so if you add new fields to this struct, please
        !           260:  * inspect bdrv_append() to determine if the new fields need to be
        !           261:  * copied as well.
        !           262:  */
1.1       root      263: struct BlockDriverState {
1.1.1.4   root      264:     int64_t total_sectors; /* if we are reading a disk image, give its
                    265:                               size in sectors */
1.1       root      266:     int read_only; /* if true, the media is read only */
1.1.1.13  root      267:     int keep_read_only; /* if true, the media was requested to stay read only */
1.1.1.12  root      268:     int open_flags; /* flags used to open the file, re-used for re-open */
1.1       root      269:     int encrypted; /* if true, the media is encrypted */
1.1.1.7   root      270:     int valid_key; /* if true, a valid encryption key has been set */
1.1.1.5   root      271:     int sg;        /* if true, the device is a /dev/sg* */
1.1.1.17! root      272:     int copy_on_read; /* if true, copy read backing sectors into image
        !           273:                          note this is a reference count */
1.1       root      274: 
1.1.1.4   root      275:     BlockDriver *drv; /* NULL means no media */
1.1       root      276:     void *opaque;
                    277: 
1.1.1.16  root      278:     void *dev;                  /* attached device model, if any */
                    279:     /* TODO change to DeviceState when all users are qdevified */
                    280:     const BlockDevOps *dev_ops;
                    281:     void *dev_opaque;
1.1.1.13  root      282: 
1.1       root      283:     char filename[1024];
                    284:     char backing_file[1024]; /* if non zero, the image is a diff of
                    285:                                 this file image */
1.1.1.10  root      286:     char backing_format[16]; /* if non-zero and backing_file exists */
1.1       root      287:     int is_temporary;
1.1.1.4   root      288: 
1.1       root      289:     BlockDriverState *backing_hd;
1.1.1.13  root      290:     BlockDriverState *file;
                    291: 
1.1.1.17! root      292:     /* number of in-flight copy-on-read requests */
        !           293:     unsigned int copy_on_read_in_flight;
1.1.1.4   root      294: 
1.1.1.17! root      295:     /* the time for latest disk I/O */
        !           296:     int64_t slice_time;
        !           297:     int64_t slice_start;
        !           298:     int64_t slice_end;
        !           299:     BlockIOLimit io_limits;
        !           300:     BlockIOBaseValue  io_base;
        !           301:     CoQueue      throttled_reqs;
        !           302:     QEMUTimer    *block_timer;
        !           303:     bool         io_limits_enabled;
1.1.1.5   root      304: 
                    305:     /* I/O stats (display with "info blockstats"). */
1.1.1.16  root      306:     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
                    307:     uint64_t nr_ops[BDRV_MAX_IOTYPE];
                    308:     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
1.1.1.13  root      309:     uint64_t wr_highest_sector;
1.1.1.5   root      310: 
1.1.1.6   root      311:     /* Whether the disk can expand beyond total_sectors */
                    312:     int growable;
                    313: 
1.1.1.10  root      314:     /* the memory alignment required for the buffers handled by this driver */
                    315:     int buffer_alignment;
                    316: 
1.1.1.11  root      317:     /* do we need to tell the quest if we have a volatile write cache? */
                    318:     int enable_write_cache;
                    319: 
1.1       root      320:     /* NOTE: the following infos are only hints for real hardware
                    321:        drivers. They are not used by the block driver */
                    322:     int cyls, heads, secs, translation;
1.1.1.13  root      323:     BlockErrorAction on_read_error, on_write_error;
1.1.1.16  root      324:     bool iostatus_enabled;
                    325:     BlockDeviceIoStatus iostatus;
1.1       root      326:     char device_name[32];
1.1.1.11  root      327:     unsigned long *dirty_bitmap;
1.1.1.13  root      328:     int64_t dirty_count;
1.1.1.14  root      329:     int in_use; /* users other than guest access, eg. block migration */
1.1.1.13  root      330:     QTAILQ_ENTRY(BlockDriverState) list;
1.1       root      331: 
1.1.1.17! root      332:     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
        !           333: 
        !           334:     /* long-running background operation */
        !           335:     BlockJob *job;
1.1.1.4   root      336: };
                    337: 
1.1.1.17! root      338: int get_tmp_filename(char *filename, int size);
1.1.1.2   root      339: 
1.1.1.17! root      340: void bdrv_set_io_limits(BlockDriverState *bs,
        !           341:                         BlockIOLimit *io_limits);
1.1.1.4   root      342: 
1.1.1.10  root      343: #ifdef _WIN32
                    344: int is_windows_drive(const char *filename);
                    345: #endif
                    346: 
1.1.1.17! root      347: /**
        !           348:  * block_job_create:
        !           349:  * @job_type: The class object for the newly-created job.
        !           350:  * @bs: The block
        !           351:  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
        !           352:  * @cb: Completion function for the job.
        !           353:  * @opaque: Opaque pointer value passed to @cb.
        !           354:  * @errp: Error object.
        !           355:  *
        !           356:  * Create a new long-running block device job and return it.  The job
        !           357:  * will call @cb asynchronously when the job completes.  Note that
        !           358:  * @bs may have been closed at the time the @cb it is called.  If
        !           359:  * this is the case, the job may be reported as either cancelled or
        !           360:  * completed.
        !           361:  *
        !           362:  * This function is not part of the public job interface; it should be
        !           363:  * called from a wrapper that is specific to the job type.
        !           364:  */
        !           365: void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
        !           366:                        int64_t speed, BlockDriverCompletionFunc *cb,
        !           367:                        void *opaque, Error **errp);
        !           368: 
        !           369: /**
        !           370:  * block_job_sleep_ns:
        !           371:  * @job: The job that calls the function.
        !           372:  * @clock: The clock to sleep on.
        !           373:  * @ns: How many nanoseconds to stop for.
        !           374:  *
        !           375:  * Put the job to sleep (assuming that it wasn't canceled) for @ns
        !           376:  * nanoseconds.  Canceling the job will interrupt the wait immediately.
        !           377:  */
        !           378: void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns);
        !           379: 
        !           380: /**
        !           381:  * block_job_complete:
        !           382:  * @job: The job being completed.
        !           383:  * @ret: The status code.
        !           384:  *
        !           385:  * Call the completion function that was registered at creation time, and
        !           386:  * free @job.
        !           387:  */
        !           388: void block_job_complete(BlockJob *job, int ret);
        !           389: 
        !           390: /**
        !           391:  * block_job_set_speed:
        !           392:  * @job: The job to set the speed for.
        !           393:  * @speed: The new value
        !           394:  * @errp: Error object.
        !           395:  *
        !           396:  * Set a rate-limiting parameter for the job; the actual meaning may
        !           397:  * vary depending on the job type.
        !           398:  */
        !           399: void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp);
        !           400: 
        !           401: /**
        !           402:  * block_job_cancel:
        !           403:  * @job: The job to be canceled.
        !           404:  *
        !           405:  * Asynchronously cancel the specified job.
        !           406:  */
        !           407: void block_job_cancel(BlockJob *job);
        !           408: 
        !           409: /**
        !           410:  * block_job_is_cancelled:
        !           411:  * @job: The job being queried.
        !           412:  *
        !           413:  * Returns whether the job is scheduled for cancellation.
        !           414:  */
        !           415: bool block_job_is_cancelled(BlockJob *job);
        !           416: 
        !           417: /**
        !           418:  * block_job_cancel:
        !           419:  * @job: The job to be canceled.
        !           420:  *
        !           421:  * Asynchronously cancel the job and wait for it to reach a quiescent
        !           422:  * state.  Note that the completion callback will still be called
        !           423:  * asynchronously, hence it is *not* valid to call #bdrv_delete
        !           424:  * immediately after #block_job_cancel_sync.  Users of block jobs
        !           425:  * will usually protect the BlockDriverState objects with a reference
        !           426:  * count, should this be a concern.
        !           427:  *
        !           428:  * Returns the return value from the job if the job actually completed
        !           429:  * during the call, or -ECANCELED if it was canceled.
        !           430:  */
        !           431: int block_job_cancel_sync(BlockJob *job);
        !           432: 
        !           433: /**
        !           434:  * stream_start:
        !           435:  * @bs: Block device to operate on.
        !           436:  * @base: Block device that will become the new base, or %NULL to
        !           437:  * flatten the whole backing file chain onto @bs.
        !           438:  * @base_id: The file name that will be written to @bs as the new
        !           439:  * backing file if the job completes.  Ignored if @base is %NULL.
        !           440:  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
        !           441:  * @cb: Completion function for the job.
        !           442:  * @opaque: Opaque pointer value passed to @cb.
        !           443:  * @errp: Error object.
        !           444:  *
        !           445:  * Start a streaming operation on @bs.  Clusters that are unallocated
        !           446:  * in @bs, but allocated in any image between @base and @bs (both
        !           447:  * exclusive) will be written to @bs.  At the end of a successful
        !           448:  * streaming job, the backing file of @bs will be changed to
        !           449:  * @base_id in the written image and to @base in the live BlockDriverState.
        !           450:  */
        !           451: void stream_start(BlockDriverState *bs, BlockDriverState *base,
        !           452:                   const char *base_id, int64_t speed,
        !           453:                   BlockDriverCompletionFunc *cb,
        !           454:                   void *opaque, Error **errp);
        !           455: 
1.1       root      456: #endif /* BLOCK_INT_H */

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