From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F38A43FF89E; Wed, 29 Apr 2026 18:08:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486081; cv=none; b=fdoGNi5OiK//RCG+r8cmq2tzcPBc6Pn9VIiWz1K1GoPP4KeIrxuMsFXo5/oL8FkdNePgOVrZp2xcG4L/arzpQWungZE3R3X/dfOBVLtxGNN+/+Njek/nGKMTjKal/FtGWkPfensWyiS04JEVZJ7aFoGQXrhyVhcsmQ9qxUBDtQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486081; c=relaxed/simple; bh=3ibEXRs6ZqvvbnwWfb9g39rNFPAvDiuuC7ysYxFiMFU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=hI80LpHfW2EBHaFlwNwgFflwjvOPqjvqr3FvCFSROy2FPeamCS2Yy40v0hz14j6pEoDxrag4jKZg7mCLCoMWKbi3pj5xWoZ32m25spMO0cPjKRCvqw7dt/nHceBR+No7LpEdxHeMmQlDyWesHHM9+YeVK64/palCaLUuaM60+EQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=avPaysqo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="avPaysqo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5290BC19425; Wed, 29 Apr 2026 18:07:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777486080; bh=3ibEXRs6ZqvvbnwWfb9g39rNFPAvDiuuC7ysYxFiMFU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=avPaysqoEqIPCzZCnl6ij89BiLHf1e+VaFwQMtv3iz7PwPXJ2F7caCqxbNmIItpZC NyUkMf0z0v/JKnu3IgN8M0X4bSaMoZmJHHd4RgVROqOKVWOXXUgqT44nGGU9MymVyR MzU7hfeha6I8cvsS8F4wx1n2QwEJeJ8+Xi1EP0q6KY1v2Fl5IVqge69y9c+gFCn8uz bkg/AhDwaHsCeNwZo0xzVFwcMkHqMrXuqzv81td6fPM0ZeQwiuwZpr+N0bmWmTYlfJ 4JOSZap4WyeGApeDeTWUBn+AytkjWPPqiVTlmPCMu8w9lQ4UYsjB9tmTGkYhXCCo1v JECjOCsojZl3w== From: Chuck Lever Date: Wed, 29 Apr 2026 14:07:24 -0400 Subject: [PATCH v12 13/15] nfsd: Report export case-folding via NFSv3 PATHCONF 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: <20260429-case-sensitivity-v12-13-8057123bebe0@oracle.com> References: <20260429-case-sensitivity-v12-0-8057123bebe0@oracle.com> In-Reply-To: <20260429-case-sensitivity-v12-0-8057123bebe0@oracle.com> To: Al Viro , Christian Brauner , Jan Kara Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, hirofumi@mail.parknet.co.jp, linkinjeon@kernel.org, sj1557.seo@samsung.com, yuezhang.mo@sony.com, almaz.alexandrovich@paragon-software.com, slava@dubeyko.com, glaubitz@physik.fu-berlin.de, frank.li@vivo.com, tytso@mit.edu, adilger.kernel@dilger.ca, cem@kernel.org, sfrench@samba.org, pc@manguebit.org, ronniesahlberg@gmail.com, sprasad@microsoft.com, trondmy@kernel.org, anna@kernel.org, jaegeuk@kernel.org, chao@kernel.org, hansg@kernel.org, senozhatsky@chromium.org, Chuck Lever , Roland Mainz X-Mailer: b4 0.16-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=6586; i=chuck.lever@oracle.com; h=from:subject:message-id; bh=IpXstYLd1S+g4AYnnCs2sKNY6pmlFdt467tqNXA8Pt4=; b=owEBbQKS/ZANAwAKATNqszNvZn+XAcsmYgBp8kjdByccVEcEEBgQ8M2KviDpwfaOt8WgIOkww rIDrOpjY0aJAjMEAAEKAB0WIQQosuWwEobfJDzyPv4zarMzb2Z/lwUCafJI3QAKCRAzarMzb2Z/ l7ddD/98CaYLuxipMbpe2ovAbP1yoj4kQpytu6hqH+62Yz7nNilpadWnIi4+mfXdyzFaEdt5p2S Itv/hOQLIgiX6VegXIUonQ3NlXL4JyNnnGKgAuixXFDE+cW76qHTXQQKeQnu+LpFSvGYr1IWxhS hnyaIW/lhxhmXoU5df/F/tR8dTFV1JLUqDBxMriUTBuNhXu+bx7Xi7b6QUeCaKL/4WPlFiujTEq plNyVFIk2dMEmBNf0H07QLO6XTzVvspi2wcwf5iXpvaH7pie0QuRH3BFTQ4MlqEEBJuuuIdg9hP X9TaWGkmIh2mNY1OQ9qCZX9rexnANVFCO469cm7fYVu3DRNONsrcsgqD1rzo0OhUzz55WT9ldIT nT0b/ConxQGMhscbm1pCJgv/IiNnZgE57Ygns3ajQwre1UUW1X0tfbMz34VkoxqZMN7CnWp2f+o UM0XOmHJm8Qs8Va99zevK/KYTwvG5x0ngTGAfsLdV5W4xEL4UQ0E3/JSyg0bK4rkqRqK40WtZO5 D7O9jiAcKSnJ0AOmwZzM4U6BUGdEfO2hNTbli9ZU+sSWpOzS9A6I+ysEFiPN6pNWNCFbSr58F3k ZyeM5hx9Scq7EkJa/HLs8JXOugEVrbNPNjeYfkupNtXGjz3HwHkKVIl3ZzPv0VcNRpbHGYKUwzg JTEtS+s5vy2AR4A== X-Developer-Key: i=chuck.lever@oracle.com; a=openpgp; fpr=28B2E5B01286DF243CF23EFE336AB3336F667F97 From: Chuck Lever The hard-coded MSDOS_SUPER_MAGIC check in nfsd3_proc_pathconf() only recognizes FAT filesystems as case-insensitive. Modern filesystems like F2FS, exFAT, and CIFS support case-insensitive directories, but NFSv3 clients cannot discover this capability. Query the export's actual case behavior through ->fileattr_get instead. This allows NFSv3 clients to correctly handle case sensitivity for any filesystem that implements the fileattr interface. Filesystems without ->fileattr_get continue to report the default POSIX behavior (case-sensitive, case-preserving). This change depends on the earlier "fat: Implement fileattr_get for case sensitivity" patch in this series, which ensures FAT filesystems report their case behavior correctly via the fileattr interface. Reviewed-by: Roland Mainz Signed-off-by: Chuck Lever --- fs/nfsd/nfs3proc.c | 36 +++++++++++++++++++++------ fs/nfsd/vfs.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nfsd/vfs.h | 3 +++ fs/nfsd/xdr3.h | 4 +-- 4 files changed, 105 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 42adc5461db0..62ebc65b8af2 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -710,23 +710,43 @@ nfsd3_proc_pathconf(struct svc_rqst *rqstp) resp->p_name_max = 255; /* at least */ resp->p_no_trunc = 0; resp->p_chown_restricted = 1; - resp->p_case_insensitive = 0; - resp->p_case_preserving = 1; + resp->p_case_insensitive = false; + resp->p_case_preserving = true; resp->status = fh_verify(rqstp, &argp->fh, 0, NFSD_MAY_NOP); if (resp->status == nfs_ok) { struct super_block *sb = argp->fh.fh_dentry->d_sb; + int err; - /* Note that we don't care for remote fs's here */ - switch (sb->s_magic) { - case EXT2_SUPER_MAGIC: + if (sb->s_magic == EXT2_SUPER_MAGIC) { resp->p_link_max = EXT2_LINK_MAX; resp->p_name_max = EXT2_NAME_LEN; + } + + err = nfsd_get_case_info(argp->fh.fh_dentry, + &resp->p_case_insensitive, + &resp->p_case_preserving); + /* + * RFC 1813 lists NFS3ERR_STALE, NFS3ERR_BADHANDLE, and + * NFS3ERR_SERVERFAULT as the only PATHCONF errors. + */ + switch (err) { + case 0: + case -EOPNOTSUPP: + /* Both arms leave the output booleans valid. */ break; - case MSDOS_SUPER_MAGIC: - resp->p_case_insensitive = 1; - resp->p_case_preserving = 0; + case -EACCES: + case -EPERM: + /* + * Policy denied the query. Report STALE so the + * handle is unusable without implying a server + * malfunction. + */ + resp->status = nfserr_stale; + break; + default: + resp->status = nfserr_serverfault; break; } } diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index eafdf7b7890f..4bd63d8efbf7 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "xdr3.h" @@ -2891,3 +2892,74 @@ nfsd_permission(struct svc_cred *cred, struct svc_export *exp, return err? nfserrno(err) : 0; } + +/** + * nfsd_get_case_info - get case sensitivity info for a dentry + * @dentry: dentry to query + * @case_insensitive: set to true if the filesystem is case-insensitive + * @case_preserving: set to true if the filesystem preserves case + * + * On casefold-capable filesystems the flag lives on the directory, + * not on its entries, so for a non-directory @dentry the parent is + * queried instead. A directory (including an export root, whose + * parent lies outside the export) is queried as-is so its own + * contents' lookup behavior is reported. + * + * When the filesystem does not expose case-folding state (no + * ->fileattr_get, or the callback returns -EOPNOTSUPP / + * -ENOIOCTLCMD / -ENOTTY / -EINVAL), the outputs are filled with + * POSIX defaults (case-sensitive, case-preserving) on the premise + * that a filesystem with case-folding support wires up + * fileattr_get. + * + * Other errors propagate unmodified (-EACCES, -EPERM from LSM + * hooks; -EIO, -ESTALE, ... from the filesystem). Case-folding + * behavior is a property of the exported filesystem, not of the + * caller's credentials, so silently substituting defaults would + * let the same dentry report POSIX while LSM denies and report + * casefolding once LSM allows -- a client could race against + * silent name collisions on a case-insensitive export. + * + * Return: 0 with outputs filled, -EOPNOTSUPP with outputs filled + * to POSIX defaults, or a negative errno with outputs + * unmodified. + */ +int +nfsd_get_case_info(struct dentry *dentry, bool *case_insensitive, + bool *case_preserving) +{ + struct file_kattr fa = {}; + struct dentry *cd; + bool put = false; + int err; + + if (d_is_dir(dentry)) { + cd = dentry; + } else { + cd = dget_parent(dentry); + put = true; + } + err = vfs_fileattr_get(cd, &fa); + if (put) + dput(cd); + switch (err) { + case 0: + *case_insensitive = fa.fsx_xflags & FS_XFLAG_CASEFOLD; + *case_preserving = + !(fa.fsx_xflags & FS_XFLAG_CASENONPRESERVING); + return 0; + case -EINVAL: + case -ENOTTY: + case -ENOIOCTLCMD: + case -EOPNOTSUPP: + /* + * Filesystem does not expose case state. + * Report POSIX defaults. + */ + *case_insensitive = false; + *case_preserving = true; + return -EOPNOTSUPP; + default: + return err; + } +} diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index 702a844f2106..e09ea04a51b9 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -156,6 +156,9 @@ __be32 nfsd_readdir(struct svc_rqst *, struct svc_fh *, loff_t *, struct readdir_cd *, nfsd_filldir_t); __be32 nfsd_statfs(struct svc_rqst *, struct svc_fh *, struct kstatfs *, int access); +int nfsd_get_case_info(struct dentry *dentry, + bool *case_insensitive, + bool *case_preserving); __be32 nfsd_permission(struct svc_cred *cred, struct svc_export *exp, struct dentry *dentry, int acc); diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h index 522067b7fd75..a7c9714b0b0e 100644 --- a/fs/nfsd/xdr3.h +++ b/fs/nfsd/xdr3.h @@ -209,8 +209,8 @@ struct nfsd3_pathconfres { __u32 p_name_max; __u32 p_no_trunc; __u32 p_chown_restricted; - __u32 p_case_insensitive; - __u32 p_case_preserving; + bool p_case_insensitive; + bool p_case_preserving; }; struct nfsd3_commitres { -- 2.53.0