{"id":2232083,"url":"http://patchwork.ozlabs.org/api/patches/2232083/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260502-case-sensitivity-v13-14-aa853140311f@oracle.com/","project":{"id":8,"url":"http://patchwork.ozlabs.org/api/projects/8/?format=json","name":"Linux ext4 filesystem development","link_name":"linux-ext4","list_id":"linux-ext4.vger.kernel.org","list_email":"linux-ext4@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260502-case-sensitivity-v13-14-aa853140311f@oracle.com>","list_archive_url":null,"date":"2026-05-02T14:20:59","name":"[v13,14/15] nfsd: Implement NFSv4 FATTR4_CASE_INSENSITIVE and FATTR4_CASE_PRESERVING","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"9c8a9354e3000b9d398a7f7dee684ceeb0e656ad","submitter":{"id":86689,"url":"http://patchwork.ozlabs.org/api/people/86689/?format=json","name":"Chuck Lever","email":"cel@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-ext4/patch/20260502-case-sensitivity-v13-14-aa853140311f@oracle.com/mbox/","series":[{"id":502531,"url":"http://patchwork.ozlabs.org/api/series/502531/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-ext4/list/?series=502531","date":"2026-05-02T14:20:45","name":"Exposing case folding behavior","version":13,"mbox":"http://patchwork.ozlabs.org/series/502531/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2232083/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2232083/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-ext4@vger.kernel.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","patchwork-incoming@ozlabs.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=rywUvWSA;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=2404:9400:2221:ea00::3; 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arc=none smtp.client-ip=10.30.226.201"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1777731756;\n\tbh=IBYLppDmEpk49AW+aDaK+jyoS+KenxvVpd0xkXYb9e4=;\n\th=From:Date:Subject:References:In-Reply-To:To:Cc:From;\n\tb=rywUvWSA3KU3kEM5YOrF4I92KWz+dtWkTT8uoGD9VBQtax69DobSaFypVCqYj1aWm\n\t q0RvEnE4pakgtcGecOU3GyFbRQONukv06+5evNASwdKplvek+qRIW0iHlCxKC6qCaT\n\t Ck8nik9bwdptwSMqQaqiUBozSQOuYujV2llca98tNPEQdDhJIWyenOiDzPOzNl37cN\n\t /E238E6IxpZ2JqOwZ77kiVDE+VrxB8HTsiaXpTkXrAmjBRJ7i0XIBjm1s/tA6X1ikR\n\t E44bksEOKBURrMDtY/VH4SR5MtShX63LW/4sJGBD4ds63MM5Ne0aCzv6rkyynC9HSc\n\t 1f7g1N/oSOu5g==","From":"Chuck Lever ","Date":"Sat, 02 May 2026 10:20:59 -0400","Subject":"[PATCH v13 14/15] nfsd: Implement NFSv4 FATTR4_CASE_INSENSITIVE\n and FATTR4_CASE_PRESERVING","Precedence":"bulk","X-Mailing-List":"linux-ext4@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"7bit","Message-Id":"<20260502-case-sensitivity-v13-14-aa853140311f@oracle.com>","References":"<20260502-case-sensitivity-v13-0-aa853140311f@oracle.com>","In-Reply-To":"<20260502-case-sensitivity-v13-0-aa853140311f@oracle.com>","To":"Al Viro ,\n Christian Brauner , Jan Kara ","Cc":"linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,\n linux-xfs@vger.kernel.org, linux-cifs@vger.kernel.org,\n linux-nfs@vger.kernel.org, linux-api@vger.kernel.org,\n linux-f2fs-devel@lists.sourceforge.net, hirofumi@mail.parknet.co.jp,\n linkinjeon@kernel.org, sj1557.seo@samsung.com, yuezhang.mo@sony.com,\n almaz.alexandrovich@paragon-software.com, slava@dubeyko.com,\n glaubitz@physik.fu-berlin.de, frank.li@vivo.com, tytso@mit.edu,\n adilger.kernel@dilger.ca, cem@kernel.org, sfrench@samba.org,\n pc@manguebit.org, ronniesahlberg@gmail.com, sprasad@microsoft.com,\n trondmy@kernel.org, anna@kernel.org, jaegeuk@kernel.org, chao@kernel.org,\n hansg@kernel.org, senozhatsky@chromium.org,\n Chuck Lever ,\n Roland Mainz ","X-Mailer":"b4 0.16-dev","X-Developer-Signature":"v=1; a=openpgp-sha256; l=4936;\n i=chuck.lever@oracle.com; h=from:subject:message-id;\n bh=ezCClrtcetCYnq60ZMthhQBIKalbwZM7UJGTvsJx60Q=;\n b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBp9ghRZHXDWrBOKBPiYd9/A/2qNYBxWjYNc1mUa\n Mba+1U/o6KJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCafYIUQAKCRAzarMzb2Z/\n l+pHD/9szCzlJ7xx0AGJZxYiKgNGx1GH4rZVoB9AGHCULctRjTS8Sr4J1/C26ripNZiaFeAruqe\n LRq0b1NedgTGLdDZTJZBWn1H3uMrSgVmicsLzCeWICFj3A/idmRcKKuhppN4Dmv1BRRoi+5QQEC\n +RIOJI1FwsXEcwMsh5h5KUz5vmqhybBVsL74+Qe3RvP8UEVC7bcmdJAjmULRjMS5By4nt4LfvyP\n CXib4VMqDBHdIX3JMUfFsQPzIOMRQGQLFPj1A5JE8UXlTbZBo0M2B2mPerQ3p7BrN6oBgkL1uba\n WkuyvGK7RLu9wASejqw9shamCX94tmP4cKSsASn4HTVPkq4Qb57V31hw0amtYul/gILYiQT6Ufp\n 4TBAiBeWBWKxK2KvSL+nFV0KfiNlvrgwA4u46Bm1KVsPgDx6EqEwcoj+qU/yFBwokxQIXAqg0Gy\n hHMl3cxIinx69VXAfXl5Rz24kCYb6QVkavxWT0uFPqGXL72vJKG82Bs7eCHX1d5EFN56wL3HR5U\n YlUi9sWmqjYOq1Kw4a0SgQb/TPJRKhCE5GFNGR5LT7YwbAAc3O7QK4kOKxtDbsuSDarbBR45EVT\n 3wELlC8ube+lyksLB+oU0QrbEayaPuxvUeXhC1p27b2YbwlyXiziuELrpS68z4c5N3JGc582u3N\n Ix2Tqk2gVUEX/+A==","X-Developer-Key":"i=chuck.lever@oracle.com; a=openpgp;\n fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97","X-Spam-Status":"No, score=-1.2 required=5.0 tests=ARC_SIGNED,ARC_VALID,\n\tDKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DMARC_PASS,\n\tMAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=disabled\n\tversion=4.0.1","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on gandalf.ozlabs.org"},"content":"From: Chuck Lever \n\nNFSD currently provides NFSv4 clients with hard-coded responses\nindicating all exported filesystems are case-sensitive and\ncase-preserving. This is incorrect for case-insensitive filesystems\nand ext4 directories with casefold enabled.\n\nQuery the underlying filesystem's actual case sensitivity via\nnfsd_get_case_info() and return accurate values to clients. This\nsupports per-directory settings for filesystems that allow mixing\ncase-sensitive and case-insensitive directories within an export.\n\nThe helper queries the parent dentry for non-directory filehandles\nbecause case-folding is a per-directory property. That resolution\nhas the same corner cases here as for NFSv3 PATHCONF: single-file\nexports query an unexported parent, disconnected dentries report\ndefaults until reconnected, and hardlinked files track whichever\nalias the dcache currently holds.\n\nReviewed-by: Roland Mainz \nSigned-off-by: Chuck Lever \n---\n fs/nfsd/nfs4xdr.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++---\n 1 file changed, 49 insertions(+), 3 deletions(-)","diff":"diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c\nindex 2a0946c630e1..d77304692e11 100644\n--- a/fs/nfsd/nfs4xdr.c\n+++ b/fs/nfsd/nfs4xdr.c\n@@ -3158,6 +3158,8 @@ struct nfsd4_fattr_args {\n \tu32\t\t\trdattr_err;\n \tbool\t\t\tcontextsupport;\n \tbool\t\t\tignore_crossmnt;\n+\tbool\t\t\tcase_insensitive;\n+\tbool\t\t\tcase_preserving;\n };\n \n typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr,\n@@ -3356,6 +3358,33 @@ static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,\n \treturn nfs_ok;\n }\n \n+static __be32 nfsd4_encode_fattr4_case_insensitive(struct xdr_stream *xdr,\n+\t\t\t\t\tconst struct nfsd4_fattr_args *args)\n+{\n+\treturn nfsd4_encode_bool(xdr, args->case_insensitive);\n+}\n+\n+static __be32 nfsd4_encode_fattr4_case_preserving(struct xdr_stream *xdr,\n+\t\t\t\t\tconst struct nfsd4_fattr_args *args)\n+{\n+\treturn nfsd4_encode_bool(xdr, args->case_preserving);\n+}\n+\n+static __be32 nfsd4_encode_fattr4_homogeneous(struct xdr_stream *xdr,\n+\t\t\t\t\tconst struct nfsd4_fattr_args *args)\n+{\n+\t/*\n+\t * Casefold-capable filesystems (e.g. ext4 or f2fs with the\n+\t * casefold feature) attach a Unicode encoding at mount time\n+\t * but apply case folding per directory. The per-file-system\n+\t * case_insensitive and case_preserving values can therefore\n+\t * legitimately differ across objects that share the same fsid.\n+\t * Report FATTR4_HOMOGENEOUS = FALSE on such filesystems to\n+\t * keep that variation consistent with RFC 8881 Section 5.8.2.16.\n+\t */\n+\treturn nfsd4_encode_bool(xdr, !sb_has_encoding(args->dentry->d_sb));\n+}\n+\n static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,\n \t\t\t\t\t const struct nfsd4_fattr_args *args)\n {\n@@ -3748,8 +3777,8 @@ static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {\n \t[FATTR4_ACLSUPPORT]\t\t= nfsd4_encode_fattr4_aclsupport,\n \t[FATTR4_ARCHIVE]\t\t= nfsd4_encode_fattr4__noop,\n \t[FATTR4_CANSETTIME]\t\t= nfsd4_encode_fattr4__true,\n-\t[FATTR4_CASE_INSENSITIVE]\t= nfsd4_encode_fattr4__false,\n-\t[FATTR4_CASE_PRESERVING]\t= nfsd4_encode_fattr4__true,\n+\t[FATTR4_CASE_INSENSITIVE]\t= nfsd4_encode_fattr4_case_insensitive,\n+\t[FATTR4_CASE_PRESERVING]\t= nfsd4_encode_fattr4_case_preserving,\n \t[FATTR4_CHOWN_RESTRICTED]\t= nfsd4_encode_fattr4__true,\n \t[FATTR4_FILEHANDLE]\t\t= nfsd4_encode_fattr4_filehandle,\n \t[FATTR4_FILEID]\t\t\t= nfsd4_encode_fattr4_fileid,\n@@ -3758,7 +3787,7 @@ static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {\n \t[FATTR4_FILES_TOTAL]\t\t= nfsd4_encode_fattr4_files_total,\n \t[FATTR4_FS_LOCATIONS]\t\t= nfsd4_encode_fattr4_fs_locations,\n \t[FATTR4_HIDDEN]\t\t\t= nfsd4_encode_fattr4__noop,\n-\t[FATTR4_HOMOGENEOUS]\t\t= nfsd4_encode_fattr4__true,\n+\t[FATTR4_HOMOGENEOUS]\t\t= nfsd4_encode_fattr4_homogeneous,\n \t[FATTR4_MAXFILESIZE]\t\t= nfsd4_encode_fattr4_maxfilesize,\n \t[FATTR4_MAXLINK]\t\t= nfsd4_encode_fattr4_maxlink,\n \t[FATTR4_MAXNAME]\t\t= nfsd4_encode_fattr4_maxname,\n@@ -3968,6 +3997,23 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,\n \t\targs.fhp = tempfh;\n \t} else\n \t\targs.fhp = fhp;\n+\tif (attrmask[0] & (FATTR4_WORD0_CASE_INSENSITIVE |\n+\t\t\t FATTR4_WORD0_CASE_PRESERVING)) {\n+\t\terr = nfsd_get_case_info(dentry, &args.case_insensitive,\n+\t\t\t\t\t &args.case_preserving);\n+\t\t/*\n+\t\t * SUPPORTED_ATTRS unconditionally advertises both\n+\t\t * bits, and the Linux client treats an absent\n+\t\t * CASE_PRESERVING in a GETATTR reply as false. When\n+\t\t * the filesystem does not expose case state,\n+\t\t * nfsd_get_case_info() fills POSIX defaults\n+\t\t * (case-sensitive, case-preserving) and returns\n+\t\t * -EOPNOTSUPP; encode those defaults so the reply\n+\t\t * agrees with what the server claims to support.\n+\t\t */\n+\t\tif (err && err != -EOPNOTSUPP)\n+\t\t\tgoto out_nfserr;\n+\t}\n \n \tif (attrmask[0] & FATTR4_WORD0_ACL) {\n \t\terr = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);\n","prefixes":["v13","14/15"]}