diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 42adc5461db0..12b9172c6be1 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..85ff418127c7 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "xdr3.h" @@ -2891,3 +2892,90 @@ 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 name comparison ignores case + * @case_preserving: set to true if case is preserved on disk + * + * 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. NFSD advertises + * fattr4_homogeneous as FALSE, so per-directory answers may differ + * within an export. + * + * The probe runs with kernel credentials. case_insensitive and + * case_preserving describe the directory's structural lookup + * behavior, not the caller's identity; running under the calling + * client's mapped credentials would let per-client MAC policy on + * the parent directory turn this query into NFS4ERR_ACCESS even + * though the underlying property is the same for every client. + * + * 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. + * + * Return: 0 with outputs filled, -EOPNOTSUPP with outputs filled + * to POSIX defaults, or a negative errno (e.g., -EIO, + * -ESTALE, -ENOMEM) with outputs unmodified. + */ +int +nfsd_get_case_info(struct dentry *dentry, bool *case_insensitive, + bool *case_preserving) +{ + struct file_kattr fa = {}; + const struct cred *saved; + struct cred *probe; + struct dentry *cd; + bool put = false; + int err; + + if (d_is_dir(dentry)) { + cd = dentry; + } else { + cd = dget_parent(dentry); + put = true; + } + + probe = prepare_creds(); + if (!probe) { + err = -ENOMEM; + goto out; + } + probe->fsuid = GLOBAL_ROOT_UID; + probe->fsgid = GLOBAL_ROOT_GID; + saved = override_creds(probe); + + err = vfs_fileattr_get(cd, &fa); + + put_cred(revert_creds(saved)); +out: + 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 {