there when writing to a non-existent file (/test/wj9.txt). I highlighted all key OS file operations in the FUSE debugging info below: ---------------------------------------------------------------------------------- unique: 22, opcode: GETATTR (3), nodeid: 1, insize: 56 *getattr /* unique: 22, success, outsize: 120 unique: 23, opcode: LOOKUP (1), nodeid: 1, insize: 45 LOOKUP /test *getattr /test* NODEID: 2 unique: 23, success, outsize: 144 unique: 24, opcode: LOOKUP (1), nodeid: 2, insize: 48 LOOKUP /test/wj9.txt *getattr /test/wj9.txt* unique: 24, error: -2 (No such file or directory), outsize: 16 unique: 25, opcode: LOOKUP (1), nodeid: 2, insize: 48 LOOKUP /test/wj9.txt *getattr /test/wj9.txt* unique: 25, error: -2 (No such file or directory), outsize: 16 unique: 26, opcode: OPENDIR (27), nodeid: 2, insize: 48 unique: 26, success, outsize: 32 unique: 27, opcode: READDIR (28), nodeid: 2, insize: 80 *readdir[0] from 0* unique: 27, success, outsize: 496 unique: 28, opcode: READDIR (28), nodeid: 2, insize: 80 unique: 28, success, outsize: 16 unique: 29, opcode: RELEASEDIR (29), nodeid: 2, insize: 64 unique: 29, success, outsize: 16 unique: 30, opcode: GETATTR (3), nodeid: 2, insize: 56 *getattr /test* unique: 30, success, outsize: 120 unique: 31, opcode: LOOKUP (1), nodeid: 2, insize: 48 LOOKUP /test/wj9.txt *getattr /test/wj9.txt* unique: 31, error: -2 (No such file or directory), outsize: 16 unique: 32, opcode: LOOKUP (1), nodeid: 2, insize: 48 LOOKUP /test/wj9.txt *getattr /test/wj9.txt* unique: 32, error: -2 (No such file or directory), outsize: 16 unique: 33, opcode: LOOKUP (1), nodeid: 2, insize: 48 LOOKUP /test/wj9.txt *getattr /test/wj9.txt* unique: 33, error: -2 (No such file or directory), outsize: 16 unique: 34, opcode: CREATE (35), nodeid: 2, insize: 64 *create flags: 0x8042 /test/wj9.txt 0100744 umask=0000* create[10570272] flags: 0x81e6 /test/wj9.txt *getattr /test/wj9.txt* NODEID: 7 unique: 34, success, outsize: 160 unique: 35, opcode: SETATTR (4), nodeid: 7, insize: 128 *truncate /test/wj9.txt 0* *getattr /test/wj9.txt* unique: 35, success, outsize: 120 unique: 36, opcode: GETATTR (3), nodeid: 2, insize: 56 *getattr /test* unique: 36, success, outsize: 120 unique: 37, opcode: WRITE (16), nodeid: 7, insize: 112 *write[10570272] 32 bytes to 0 flags: 0xa002* write[10570272] 32 bytes to 0 unique: 37, success, outsize: 24 unique: 38, opcode: WRITE (16), nodeid: 7, insize: 112 *write[10570272] 32 bytes to 32 flags: 0xa002* write[10570272] 32 bytes to 32 unique: 38, success, outsize: 24 unique: 39, opcode: FLUSH (25), nodeid: 7, insize: 64 *flush[10570272]* unique: 39, success, outsize: 16 unique: 40, opcode: RELEASE (18), nodeid: 7, insize: 64 *release[10570272] flags: 0x8002* unique: 40, success, outsize: 16 unique: 41, opcode: GETATTR (3), nodeid: 7, insize: 56 *getattr /test/wj9.txt* unique: 41, success, outsize: 120 unique: 42, opcode: SETATTR (4), nodeid: 7, insize: 128 utimens /test/wj9.txt 1000000000.000000000 1273643329.801998000 *getattr /test/wj9.txt* unique: 42, success, outsize: 120 ---------------------------------------------------------------------------------- However, if I write to an existent file (/test/wj12.txt), there is no readdir operation. I highlighted all key OS file operations in the FUSE debugging info below: ---------------------------------------------------------------------------------- unique: 5, opcode: GETATTR (3), nodeid: 1, insize: 56 *getattr /* unique: 5, success, outsize: 120 unique: 6, opcode: LOOKUP (1), nodeid: 1, insize: 45 LOOKUP /test *getattr /test* NODEID: 2 unique: 6, success, outsize: 144 unique: 7, opcode: LOOKUP (1), nodeid: 2, insize: 49 LOOKUP /test/wj12.txt *getattr /test/wj12.txt* NODEID: 3 unique: 7, success, outsize: 144 unique: 8, opcode: OPEN (14), nodeid: 3, insize: 48 *open flags: 0x8002 /test/wj12.txt* open[16502720] flags: 0x8002 /test/wj12.txt unique: 8, success, outsize: 32 unique: 9, opcode: SETATTR (4), nodeid: 3, insize: 128 *truncate /test/wj12.txt 0* *getattr /test/wj12.txt* unique: 9, success, outsize: 120 unique: 10, opcode: GETXATTR (22), nodeid: 3, insize: 72 unique: 10, error: -38 (Function not implemented), outsize: 16 unique: 11, opcode: WRITE (16), nodeid: 3, insize: 112 *write[16502720] 32 bytes to 0 flags: 0x8002* write[16502720] 32 bytes to 0 unique: 11, success, outsize: 24 unique: 12, opcode: WRITE (16), nodeid: 3, insize: 112 *write[16502720] 32 bytes to 32 flags: 0x8002* write[16502720] 32 bytes to 32 unique: 12, success, outsize: 24 unique: 13, opcode: FLUSH (25), nodeid: 3, insize: 64 *flush[16502720]* unique: 13, success, outsize: 16 unique: 14, opcode: RELEASE (18), nodeid: 3, insize: 64 *release[16502720] flags: 0x8002* unique: 14, success, outsize: 16 unique: 15, opcode: GETATTR (3), nodeid: 3, insize: 56 *getattr /test/wj12.txt* unique: 15, success, outsize: 120 unique: 16, opcode: SETATTR (4), nodeid: 3, insize: 128 utimens /test/wj12.txt 1000000000.000000000 1273651911.055820000 *getattr /test/wj12.txt* unique: 16, success, outsize: 120 ---------------------------------------------------------------------------------- Thanks! Best regards, Zhang Bingjun, Eddy