Date: Wed, 27 Mar 2013 18:31:02 -0700 From: Matthew Fleming <mdf356@gmail.com> To: freebsd-current@freebsd.org, freebsd-fs@freebsd.org Subject: [RFC] use a shared lock for VOP_GETEXTATTR Message-ID: <CAMBSHm8Akz2-tUhjYm9%2BH3YTN31N8=OhGHX1ZpdV4-VixFQm%2BQ@mail.gmail.com>
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--000e0cd5ccee951c6904d8f21bef Content-Type: text/plain; charset=ISO-8859-1 VOP_GETEXTATTR is currently called with an exclusive lock, which seems like overkill for what is essentially a read operation. I had a look over the various in-tree filesystems and it didn't look like any of them will have a problem if a shared-mode lock is used for vop_getextattr. Does anyone know otherwise? Is someone using extended attributes regularly who can test this? Thanks, matthew --000e0cd5ccee951c6904d8f21bef Content-Type: application/octet-stream; name="0001-Use-a-shared-lock-for-VOP_GETEXTATTR-as-it-is-a-read.patch" Content-Disposition: attachment; filename="0001-Use-a-shared-lock-for-VOP_GETEXTATTR-as-it-is-a-read.patch" Content-Transfer-Encoding: base64 X-Attachment-Id: f_het8w2zm0 RnJvbSBhYTZkNmM3MTZiZDE5Y2UzMmUzYjkwODcyN2ZiZGE2NWQzNDViN2FiIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBNYXR0aGV3IEZsZW1pbmcgPG1kZkBGcmVlQlNELm9yZz4KRGF0 ZTogV2VkLCAyNyBNYXIgMjAxMyAxODoyMzoxNyAtMDcwMApTdWJqZWN0OiBbUEFUQ0hdIFVzZSBh IHNoYXJlZCBsb2NrIGZvciBWT1BfR0VURVhUQVRUUiwgYXMgaXQgaXMgYSByZWFkLWxpa2Ugb3Bl cmF0aW9uLgoKTUZDIGFmdGVyOgkxIHdlZWsKLS0tCiBzeXMva2Vybi92ZnNfZXh0YXR0ci5jIHwg ICAgMiArLQogc3lzL2tlcm4vdmZzX3Zub3BzLmMgICB8ICAgIDIgKy0KIDIgZmlsZXMgY2hhbmdl ZCwgMiBpbnNlcnRpb25zKCspLCAyIGRlbGV0aW9ucygtKQoKZGlmZiAtLWdpdCBhL3N5cy9rZXJu L3Zmc19leHRhdHRyLmMgYi9zeXMva2Vybi92ZnNfZXh0YXR0ci5jCmluZGV4IDg1ZmM4MzkuLjcw MGE3MGMgMTAwNjQ0Ci0tLSBhL3N5cy9rZXJuL3Zmc19leHRhdHRyLmMKKysrIGIvc3lzL2tlcm4v dmZzX2V4dGF0dHIuYwpAQCAtMzIxLDE3ICszMjEsMTcgQEAgZXh0YXR0cl9nZXRfdnAoc3RydWN0 IHZub2RlICp2cCwgaW50IGF0dHJuYW1lc3BhY2UsIGNvbnN0IGNoYXIgKmF0dHJuYW1lLAogICAg IHZvaWQgKmRhdGEsIHNpemVfdCBuYnl0ZXMsIHN0cnVjdCB0aHJlYWQgKnRkKQogewogCXN0cnVj dCB1aW8gYXVpbywgKmF1aW9wOwogCXN0cnVjdCBpb3ZlYyBhaW92OwogCXNzaXplX3QgY250Owog CXNpemVfdCBzaXplLCAqc2l6ZXA7CiAJaW50IGVycm9yOwogCi0Jdm5fbG9jayh2cCwgTEtfRVhD TFVTSVZFIHwgTEtfUkVUUlkpOworCXZuX2xvY2sodnAsIExLX1NIQVJFRCB8IExLX1JFVFJZKTsK IAogCS8qCiAJICogU2xpZ2h0bHkgdW51c3VhbCBzZW1hbnRpY3M6IGlmIHRoZSB1c2VyIHByb3Zp ZGVzIGEgTlVMTCBkYXRhCiAJICogcG9pbnRlciwgdGhleSBkb24ndCB3YW50IHRvIHJlY2VpdmUg dGhlIGRhdGEsIGp1c3QgdGhlIG1heGltdW0KIAkgKiByZWFkIGxlbmd0aC4KIAkgKi8KIAlhdWlv cCA9IE5VTEw7CiAJc2l6ZXAgPSBOVUxMOwpkaWZmIC0tZ2l0IGEvc3lzL2tlcm4vdmZzX3Zub3Bz LmMgYi9zeXMva2Vybi92ZnNfdm5vcHMuYwppbmRleCBjOGY4MzJmLi42ODQ5NzMwIDEwMDY0NAot LS0gYS9zeXMva2Vybi92ZnNfdm5vcHMuYworKysgYi9zeXMva2Vybi92ZnNfdm5vcHMuYwpAQCAt MTc1MywxNyArMTc1MywxNyBAQCB2bl9leHRhdHRyX2dldChzdHJ1Y3Qgdm5vZGUgKnZwLCBpbnQg aW9mbGcsIGludCBhdHRybmFtZXNwYWNlLAogCWF1aW8udWlvX2lvdmNudCA9IDE7CiAJYXVpby51 aW9fcncgPSBVSU9fUkVBRDsKIAlhdWlvLnVpb19zZWdmbGcgPSBVSU9fU1lTU1BBQ0U7CiAJYXVp by51aW9fdGQgPSB0ZDsKIAlhdWlvLnVpb19vZmZzZXQgPSAwOwogCWF1aW8udWlvX3Jlc2lkID0g KmJ1ZmxlbjsKIAogCWlmICgoaW9mbGcgJiBJT19OT0RFTE9DS0VEKSA9PSAwKQotCQl2bl9sb2Nr KHZwLCBMS19FWENMVVNJVkUgfCBMS19SRVRSWSk7CisJCXZuX2xvY2sodnAsIExLX1NIQVJFRCB8 IExLX1JFVFJZKTsKIAogCUFTU0VSVF9WT1BfTE9DS0VEKHZwLCAiSU9fTk9ERUxPQ0tFRCB3aXRo IG5vIHZwIGxvY2sgaGVsZCIpOwogCiAJLyogYXV0aG9yaXplIGF0dHJpYnV0ZSByZXRyaWV2YWwg YXMga2VybmVsICovCiAJZXJyb3IgPSBWT1BfR0VURVhUQVRUUih2cCwgYXR0cm5hbWVzcGFjZSwg YXR0cm5hbWUsICZhdWlvLCBOVUxMLCBOVUxMLAogCSAgICB0ZCk7CiAKIAlpZiAoKGlvZmxnICYg SU9fTk9ERUxPQ0tFRCkgPT0gMCkKLS0gCjEuNy4zLjIKCg== --000e0cd5ccee951c6904d8f21bef--
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