From 874c7b8ea545c7ebc50990843a234eafbc5c0c7f Mon Sep 17 00:00:00 2001 From: Frank van der Linden Date: Tue, 23 Jun 2020 22:39:21 +0000 Subject: nfsd: split off the write decode code into a separate function nfs4_decode_write has code to parse incoming XDR write data in to a kvec head, and a list of pages. Put this code in to a separate function, so that it can be used later by the xattr code, for setxattr. No functional change. Signed-off-by: Frank van der Linden Signed-off-by: Chuck Lever --- fs/nfsd/nfs4xdr.c | 72 ++++++++++++++++++++++++++++++++----------------------- 1 file changed, 42 insertions(+), 30 deletions(-) (limited to 'fs/nfsd/nfs4xdr.c') diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 996ac01ee977..48806b493eba 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -257,6 +257,44 @@ svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len) return p; } +static __be32 +svcxdr_construct_vector(struct nfsd4_compoundargs *argp, struct kvec *head, + struct page ***pagelist, u32 buflen) +{ + int avail; + int len; + int pages; + + /* Sorry .. no magic macros for this.. * + * READ_BUF(write->wr_buflen); + * SAVEMEM(write->wr_buf, write->wr_buflen); + */ + avail = (char *)argp->end - (char *)argp->p; + if (avail + argp->pagelen < buflen) { + dprintk("NFSD: xdr error (%s:%d)\n", + __FILE__, __LINE__); + return nfserr_bad_xdr; + } + head->iov_base = argp->p; + head->iov_len = avail; + *pagelist = argp->pagelist; + + len = XDR_QUADLEN(buflen) << 2; + if (len >= avail) { + len -= avail; + + pages = len >> PAGE_SHIFT; + argp->pagelist += pages; + argp->pagelen -= pages * PAGE_SIZE; + len -= pages * PAGE_SIZE; + + next_decode_page(argp); + } + argp->p += XDR_QUADLEN(len); + + return 0; +} + /** * savemem - duplicate a chunk of memory for later processing * @argp: NFSv4 compound argument structure to be freed with @@ -1265,8 +1303,6 @@ nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify static __be32 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) { - int avail; - int len; DECODE_HEAD; status = nfsd4_decode_stateid(argp, &write->wr_stateid); @@ -1279,34 +1315,10 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) goto xdr_error; write->wr_buflen = be32_to_cpup(p++); - /* Sorry .. no magic macros for this.. * - * READ_BUF(write->wr_buflen); - * SAVEMEM(write->wr_buf, write->wr_buflen); - */ - avail = (char*)argp->end - (char*)argp->p; - if (avail + argp->pagelen < write->wr_buflen) { - dprintk("NFSD: xdr error (%s:%d)\n", - __FILE__, __LINE__); - goto xdr_error; - } - write->wr_head.iov_base = p; - write->wr_head.iov_len = avail; - write->wr_pagelist = argp->pagelist; - - len = XDR_QUADLEN(write->wr_buflen) << 2; - if (len >= avail) { - int pages; - - len -= avail; - - pages = len >> PAGE_SHIFT; - argp->pagelist += pages; - argp->pagelen -= pages * PAGE_SIZE; - len -= pages * PAGE_SIZE; - - next_decode_page(argp); - } - argp->p += XDR_QUADLEN(len); + status = svcxdr_construct_vector(argp, &write->wr_head, + &write->wr_pagelist, write->wr_buflen); + if (status) + return status; DECODE_TAIL; } -- cgit v1.2.3 From 23e50fe3a5e6045a573c69d4b0e3d78aa6183323 Mon Sep 17 00:00:00 2001 From: Frank van der Linden Date: Tue, 23 Jun 2020 22:39:26 +0000 Subject: nfsd: implement the xattr functions and en/decode logic Implement the main entry points for the *XATTR operations. Add functions to calculate the reply size for the user extended attribute operations, and implement the XDR encode / decode logic for these operations. Add the user extended attributes operations to nfsd4_ops. Signed-off-by: Frank van der Linden Signed-off-by: Chuck Lever --- fs/nfsd/nfs4proc.c | 120 ++++++++++++++ fs/nfsd/nfs4xdr.c | 450 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/nfs4.h | 2 +- 3 files changed, 571 insertions(+), 1 deletion(-) (limited to 'fs/nfsd/nfs4xdr.c') diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 841aad772798..a527da3d8052 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -2097,6 +2097,68 @@ out: } #endif /* CONFIG_NFSD_PNFS */ +static __be32 +nfsd4_getxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, + union nfsd4_op_u *u) +{ + struct nfsd4_getxattr *getxattr = &u->getxattr; + + return nfsd_getxattr(rqstp, &cstate->current_fh, + getxattr->getxa_name, &getxattr->getxa_buf, + &getxattr->getxa_len); +} + +static __be32 +nfsd4_setxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, + union nfsd4_op_u *u) +{ + struct nfsd4_setxattr *setxattr = &u->setxattr; + __be32 ret; + + if (opens_in_grace(SVC_NET(rqstp))) + return nfserr_grace; + + ret = nfsd_setxattr(rqstp, &cstate->current_fh, setxattr->setxa_name, + setxattr->setxa_buf, setxattr->setxa_len, + setxattr->setxa_flags); + + if (!ret) + set_change_info(&setxattr->setxa_cinfo, &cstate->current_fh); + + return ret; +} + +static __be32 +nfsd4_listxattrs(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, + union nfsd4_op_u *u) +{ + /* + * Get the entire list, then copy out only the user attributes + * in the encode function. + */ + return nfsd_listxattr(rqstp, &cstate->current_fh, + &u->listxattrs.lsxa_buf, &u->listxattrs.lsxa_len); +} + +static __be32 +nfsd4_removexattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, + union nfsd4_op_u *u) +{ + struct nfsd4_removexattr *removexattr = &u->removexattr; + __be32 ret; + + if (opens_in_grace(SVC_NET(rqstp))) + return nfserr_grace; + + ret = nfsd_removexattr(rqstp, &cstate->current_fh, + removexattr->rmxa_name); + + if (!ret) + set_change_info(&removexattr->rmxa_cinfo, &cstate->current_fh); + + return ret; +} + /* * NULL call. */ @@ -2706,6 +2768,42 @@ static inline u32 nfsd4_seek_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op) return (op_encode_hdr_size + 3) * sizeof(__be32); } +static inline u32 nfsd4_getxattr_rsize(struct svc_rqst *rqstp, + struct nfsd4_op *op) +{ + u32 maxcount, rlen; + + maxcount = svc_max_payload(rqstp); + rlen = min_t(u32, XATTR_SIZE_MAX, maxcount); + + return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32); +} + +static inline u32 nfsd4_setxattr_rsize(struct svc_rqst *rqstp, + struct nfsd4_op *op) +{ + return (op_encode_hdr_size + op_encode_change_info_maxsz) + * sizeof(__be32); +} +static inline u32 nfsd4_listxattrs_rsize(struct svc_rqst *rqstp, + struct nfsd4_op *op) +{ + u32 maxcount, rlen; + + maxcount = svc_max_payload(rqstp); + rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount); + + return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32); +} + +static inline u32 nfsd4_removexattr_rsize(struct svc_rqst *rqstp, + struct nfsd4_op *op) +{ + return (op_encode_hdr_size + op_encode_change_info_maxsz) + * sizeof(__be32); +} + + static const struct nfsd4_operation nfsd4_ops[] = { [OP_ACCESS] = { .op_func = nfsd4_access, @@ -3087,6 +3185,28 @@ static const struct nfsd4_operation nfsd4_ops[] = { .op_name = "OP_COPY_NOTIFY", .op_rsize_bop = nfsd4_copy_notify_rsize, }, + [OP_GETXATTR] = { + .op_func = nfsd4_getxattr, + .op_name = "OP_GETXATTR", + .op_rsize_bop = nfsd4_getxattr_rsize, + }, + [OP_SETXATTR] = { + .op_func = nfsd4_setxattr, + .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME, + .op_name = "OP_SETXATTR", + .op_rsize_bop = nfsd4_setxattr_rsize, + }, + [OP_LISTXATTRS] = { + .op_func = nfsd4_listxattrs, + .op_name = "OP_LISTXATTRS", + .op_rsize_bop = nfsd4_listxattrs_rsize, + }, + [OP_REMOVEXATTR] = { + .op_func = nfsd4_removexattr, + .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME, + .op_name = "OP_REMOVEXATTR", + .op_rsize_bop = nfsd4_removexattr_rsize, + }, }; /** diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 48806b493eba..8bacc0ceae19 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -41,6 +41,8 @@ #include #include #include +#include +#include #include "idmap.h" #include "acl.h" @@ -1877,6 +1879,208 @@ nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek) DECODE_TAIL; } +/* + * XDR data that is more than PAGE_SIZE in size is normally part of a + * read or write. However, the size of extended attributes is limited + * by the maximum request size, and then further limited by the underlying + * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX + * is 64k). Since there is no kvec- or page-based interface to xattrs, + * and we're not dealing with contiguous pages, we need to do some copying. + */ + +/* + * Decode data into buffer. Uses head and pages constructed by + * svcxdr_construct_vector. + */ +static __be32 +nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct kvec *head, + struct page **pages, char **bufp, u32 buflen) +{ + char *tmp, *dp; + u32 len; + + if (buflen <= head->iov_len) { + /* + * We're in luck, the head has enough space. Just return + * the head, no need for copying. + */ + *bufp = head->iov_base; + return 0; + } + + tmp = svcxdr_tmpalloc(argp, buflen); + if (tmp == NULL) + return nfserr_jukebox; + + dp = tmp; + memcpy(dp, head->iov_base, head->iov_len); + buflen -= head->iov_len; + dp += head->iov_len; + + while (buflen > 0) { + len = min_t(u32, buflen, PAGE_SIZE); + memcpy(dp, page_address(*pages), len); + + buflen -= len; + dp += len; + pages++; + } + + *bufp = tmp; + return 0; +} + +/* + * Get a user extended attribute name from the XDR buffer. + * It will not have the "user." prefix, so prepend it. + * Lastly, check for nul characters in the name. + */ +static __be32 +nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep) +{ + DECODE_HEAD; + char *name, *sp, *dp; + u32 namelen, cnt; + + READ_BUF(4); + namelen = be32_to_cpup(p++); + + if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN)) + return nfserr_nametoolong; + + if (namelen == 0) + goto xdr_error; + + READ_BUF(namelen); + + name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1); + if (!name) + return nfserr_jukebox; + + memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN); + + /* + * Copy the extended attribute name over while checking for 0 + * characters. + */ + sp = (char *)p; + dp = name + XATTR_USER_PREFIX_LEN; + cnt = namelen; + + while (cnt-- > 0) { + if (*sp == '\0') + goto xdr_error; + *dp++ = *sp++; + } + *dp = '\0'; + + *namep = name; + + DECODE_TAIL; +} + +/* + * A GETXATTR op request comes without a length specifier. We just set the + * maximum length for the reply based on XATTR_SIZE_MAX and the maximum + * channel reply size. nfsd_getxattr will probe the length of the xattr, + * check it against getxa_len, and allocate + return the value. + */ +static __be32 +nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp, + struct nfsd4_getxattr *getxattr) +{ + __be32 status; + u32 maxcount; + + status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name); + if (status) + return status; + + maxcount = svc_max_payload(argp->rqstp); + maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount); + + getxattr->getxa_len = maxcount; + + return status; +} + +static __be32 +nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp, + struct nfsd4_setxattr *setxattr) +{ + DECODE_HEAD; + u32 flags, maxcount, size; + struct kvec head; + struct page **pagelist; + + READ_BUF(4); + flags = be32_to_cpup(p++); + + if (flags > SETXATTR4_REPLACE) + return nfserr_inval; + setxattr->setxa_flags = flags; + + status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name); + if (status) + return status; + + maxcount = svc_max_payload(argp->rqstp); + maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount); + + READ_BUF(4); + size = be32_to_cpup(p++); + if (size > maxcount) + return nfserr_xattr2big; + + setxattr->setxa_len = size; + if (size > 0) { + status = svcxdr_construct_vector(argp, &head, &pagelist, size); + if (status) + return status; + + status = nfsd4_vbuf_from_vector(argp, &head, pagelist, + &setxattr->setxa_buf, size); + } + + DECODE_TAIL; +} + +static __be32 +nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp, + struct nfsd4_listxattrs *listxattrs) +{ + DECODE_HEAD; + u32 maxcount; + + READ_BUF(12); + p = xdr_decode_hyper(p, &listxattrs->lsxa_cookie); + + /* + * If the cookie is too large to have even one user.x attribute + * plus trailing '\0' left in a maximum size buffer, it's invalid. + */ + if (listxattrs->lsxa_cookie >= + (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2))) + return nfserr_badcookie; + + maxcount = be32_to_cpup(p++); + if (maxcount < 8) + /* Always need at least 2 words (length and one character) */ + return nfserr_inval; + + maxcount = min(maxcount, svc_max_payload(argp->rqstp)); + listxattrs->lsxa_maxcount = maxcount; + + DECODE_TAIL; +} + +static __be32 +nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp, + struct nfsd4_removexattr *removexattr) +{ + return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name); +} + static __be32 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p) { @@ -1973,6 +2177,11 @@ static const nfsd4_dec nfsd4_dec_ops[] = { [OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek, [OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp, [OP_CLONE] = (nfsd4_dec)nfsd4_decode_clone, + /* RFC 8276 extended atributes operations */ + [OP_GETXATTR] = (nfsd4_dec)nfsd4_decode_getxattr, + [OP_SETXATTR] = (nfsd4_dec)nfsd4_decode_setxattr, + [OP_LISTXATTRS] = (nfsd4_dec)nfsd4_decode_listxattrs, + [OP_REMOVEXATTR] = (nfsd4_dec)nfsd4_decode_removexattr, }; static inline bool @@ -4458,6 +4667,241 @@ nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p) return nfserr; } +/* + * Encode kmalloc-ed buffer in to XDR stream. + */ +static int +nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen) +{ + u32 cplen; + __be32 *p; + + cplen = min_t(unsigned long, buflen, + ((void *)xdr->end - (void *)xdr->p)); + p = xdr_reserve_space(xdr, cplen); + if (!p) + return nfserr_resource; + + memcpy(p, buf, cplen); + buf += cplen; + buflen -= cplen; + + while (buflen) { + cplen = min_t(u32, buflen, PAGE_SIZE); + p = xdr_reserve_space(xdr, cplen); + if (!p) + return nfserr_resource; + + memcpy(p, buf, cplen); + + if (cplen < PAGE_SIZE) { + /* + * We're done, with a length that wasn't page + * aligned, so possibly not word aligned. Pad + * any trailing bytes with 0. + */ + xdr_encode_opaque_fixed(p, NULL, cplen); + break; + } + + buflen -= PAGE_SIZE; + buf += PAGE_SIZE; + } + + return 0; +} + +static __be32 +nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_getxattr *getxattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p, err; + + p = xdr_reserve_space(xdr, 4); + if (!p) + return nfserr_resource; + + *p = cpu_to_be32(getxattr->getxa_len); + + if (getxattr->getxa_len == 0) + return 0; + + err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf, + getxattr->getxa_len); + + kvfree(getxattr->getxa_buf); + + return err; +} + +static __be32 +nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_setxattr *setxattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p; + + p = xdr_reserve_space(xdr, 20); + if (!p) + return nfserr_resource; + + encode_cinfo(p, &setxattr->setxa_cinfo); + + return 0; +} + +/* + * See if there are cookie values that can be rejected outright. + */ +static __be32 +nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs, + u32 *offsetp) +{ + u64 cookie = listxattrs->lsxa_cookie; + + /* + * If the cookie is larger than the maximum number we can fit + * in either the buffer we just got back from vfs_listxattr, or, + * XDR-encoded, in the return buffer, it's invalid. + */ + if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2)) + return nfserr_badcookie; + + if (cookie > (listxattrs->lsxa_maxcount / + (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4))) + return nfserr_badcookie; + + *offsetp = (u32)cookie; + return 0; +} + +static __be32 +nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_listxattrs *listxattrs) +{ + struct xdr_stream *xdr = &resp->xdr; + u32 cookie_offset, count_offset, eof; + u32 left, xdrleft, slen, count; + u32 xdrlen, offset; + u64 cookie; + char *sp; + __be32 status; + __be32 *p; + u32 nuser; + + eof = 1; + + status = nfsd4_listxattr_validate_cookie(listxattrs, &offset); + if (status) + goto out; + + /* + * Reserve space for the cookie and the name array count. Record + * the offsets to save them later. + */ + cookie_offset = xdr->buf->len; + count_offset = cookie_offset + 8; + p = xdr_reserve_space(xdr, 12); + if (!p) { + status = nfserr_resource; + goto out; + } + + count = 0; + left = listxattrs->lsxa_len; + sp = listxattrs->lsxa_buf; + nuser = 0; + + xdrleft = listxattrs->lsxa_maxcount; + + while (left > 0 && xdrleft > 0) { + slen = strlen(sp); + + /* + * Check if this a user. attribute, skip it if not. + */ + if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) + goto contloop; + + slen -= XATTR_USER_PREFIX_LEN; + xdrlen = 4 + ((slen + 3) & ~3); + if (xdrlen > xdrleft) { + if (count == 0) { + /* + * Can't even fit the first attribute name. + */ + status = nfserr_toosmall; + goto out; + } + eof = 0; + goto wreof; + } + + left -= XATTR_USER_PREFIX_LEN; + sp += XATTR_USER_PREFIX_LEN; + if (nuser++ < offset) + goto contloop; + + + p = xdr_reserve_space(xdr, xdrlen); + if (!p) { + status = nfserr_resource; + goto out; + } + + p = xdr_encode_opaque(p, sp, slen); + + xdrleft -= xdrlen; + count++; +contloop: + sp += slen + 1; + left -= slen + 1; + } + + /* + * If there were user attributes to copy, but we didn't copy + * any, the offset was too large (e.g. the cookie was invalid). + */ + if (nuser > 0 && count == 0) { + status = nfserr_badcookie; + goto out; + } + +wreof: + p = xdr_reserve_space(xdr, 4); + if (!p) { + status = nfserr_resource; + goto out; + } + *p = cpu_to_be32(eof); + + cookie = offset + count; + + write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8); + count = htonl(count); + write_bytes_to_xdr_buf(xdr->buf, count_offset, &count, 4); +out: + if (listxattrs->lsxa_len) + kvfree(listxattrs->lsxa_buf); + return status; +} + +static __be32 +nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr, + struct nfsd4_removexattr *removexattr) +{ + struct xdr_stream *xdr = &resp->xdr; + __be32 *p; + + p = xdr_reserve_space(xdr, 20); + if (!p) + return nfserr_resource; + + p = encode_cinfo(p, &removexattr->rmxa_cinfo); + return 0; +} + typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *); /* @@ -4547,6 +4991,12 @@ static const nfsd4_enc nfsd4_enc_ops[] = { [OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek, [OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop, [OP_CLONE] = (nfsd4_enc)nfsd4_encode_noop, + + /* RFC 8276 extended atributes operations */ + [OP_GETXATTR] = (nfsd4_enc)nfsd4_encode_getxattr, + [OP_SETXATTR] = (nfsd4_enc)nfsd4_encode_setxattr, + [OP_LISTXATTRS] = (nfsd4_enc)nfsd4_encode_listxattrs, + [OP_REMOVEXATTR] = (nfsd4_enc)nfsd4_encode_removexattr, }; /* diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h index e6ca9d1d2e76..33ebe476428e 100644 --- a/include/linux/nfs4.h +++ b/include/linux/nfs4.h @@ -165,7 +165,7 @@ Needs to be updated if more operations are defined in future.*/ #define FIRST_NFS4_OP OP_ACCESS #define LAST_NFS40_OP OP_RELEASE_LOCKOWNER #define LAST_NFS41_OP OP_RECLAIM_COMPLETE -#define LAST_NFS42_OP OP_CLONE +#define LAST_NFS42_OP OP_REMOVEXATTR #define LAST_NFS4_OP LAST_NFS42_OP enum nfsstat4 { -- cgit v1.2.3 From 0e885e846d96df0c8a4a829b1ad355a82ccda656 Mon Sep 17 00:00:00 2001 From: Frank van der Linden Date: Tue, 23 Jun 2020 22:39:27 +0000 Subject: nfsd: add fattr support for user extended attributes Check if user extended attributes are supported for an inode, and return the answer when being queried for file attributes. An exported filesystem can now signal its RFC8276 user extended attributes capability. Signed-off-by: Frank van der Linden Signed-off-by: Chuck Lever --- fs/nfsd/nfs4xdr.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'fs/nfsd/nfs4xdr.c') diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 8bacc0ceae19..259d5ad0e3f4 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3213,6 +3213,15 @@ out_acl: } #endif + if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) { + p = xdr_reserve_space(xdr, 4); + if (!p) + goto out_resource; + err = xattr_supported_namespace(d_inode(dentry), + XATTR_USER_PREFIX); + *p++ = cpu_to_be32(err == 0); + } + attrlen = htonl(xdr->buf->len - attrlen_offset - 4); write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4); status = nfs_ok; -- cgit v1.2.3