Hi Olga, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on trondmy-nfs/linux-next] [also build test WARNING on v5.18 next-20220531] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/intel-lab-lkp/linux/commits/Olga-Kornievskaia/pNFS-fix-IO-thread-starvation-problem-during-LAYOUTUNAVAILABLE-error/20220531-215040 base: git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next config: arc-allyesconfig (https://download.01.org/0day-ci/archive/20220601/202206010131.m809TcwM-lkp@xxxxxxxxx/config) compiler: arceb-elf-gcc (GCC) 11.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/7f80a6c53d6cdb806706a8748cb79348f9906229 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Olga-Kornievskaia/pNFS-fix-IO-thread-starvation-problem-during-LAYOUTUNAVAILABLE-error/20220531-215040 git checkout 7f80a6c53d6cdb806706a8748cb79348f9906229 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash fs/nfs/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): fs/nfs/pnfs.c: In function 'pnfs_update_layout': >> fs/nfs/pnfs.c:2164:25: warning: this statement may fall through [-Wimplicit-fallthrough=] 2164 | set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/nfs/pnfs.c:2165:17: note: here 2165 | default: | ^~~~~~~ vim +2164 fs/nfs/pnfs.c 1952 1953 /* 1954 * Layout segment is retreived from the server if not cached. 1955 * The appropriate layout segment is referenced and returned to the caller. 1956 */ 1957 struct pnfs_layout_segment * 1958 pnfs_update_layout(struct inode *ino, 1959 struct nfs_open_context *ctx, 1960 loff_t pos, 1961 u64 count, 1962 enum pnfs_iomode iomode, 1963 bool strict_iomode, 1964 gfp_t gfp_flags) 1965 { 1966 struct pnfs_layout_range arg = { 1967 .iomode = iomode, 1968 .offset = pos, 1969 .length = count, 1970 }; 1971 unsigned pg_offset; 1972 struct nfs_server *server = NFS_SERVER(ino); 1973 struct nfs_client *clp = server->nfs_client; 1974 struct pnfs_layout_hdr *lo = NULL; 1975 struct pnfs_layout_segment *lseg = NULL; 1976 struct nfs4_layoutget *lgp; 1977 nfs4_stateid stateid; 1978 long timeout = 0; 1979 unsigned long giveup = jiffies + (clp->cl_lease_time << 1); 1980 bool first; 1981 1982 if (!pnfs_enabled_sb(NFS_SERVER(ino))) { 1983 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 1984 PNFS_UPDATE_LAYOUT_NO_PNFS); 1985 goto out; 1986 } 1987 1988 if (pnfs_within_mdsthreshold(ctx, ino, iomode)) { 1989 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 1990 PNFS_UPDATE_LAYOUT_MDSTHRESH); 1991 goto out; 1992 } 1993 1994 lookup_again: 1995 lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp)); 1996 if (IS_ERR(lseg)) 1997 goto out; 1998 first = false; 1999 spin_lock(&ino->i_lock); 2000 lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags); 2001 if (lo == NULL) { 2002 spin_unlock(&ino->i_lock); 2003 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2004 PNFS_UPDATE_LAYOUT_NOMEM); 2005 goto out; 2006 } 2007 2008 /* Do we even need to bother with this? */ 2009 if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) { 2010 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2011 PNFS_UPDATE_LAYOUT_BULK_RECALL); 2012 dprintk("%s matches recall, use MDS\n", __func__); 2013 goto out_unlock; 2014 } 2015 2016 /* if LAYOUTGET already failed once we don't try again */ 2017 if (pnfs_layout_io_test_failed(lo, iomode)) { 2018 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2019 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL); 2020 goto out_unlock; 2021 } 2022 2023 /* 2024 * If the layout segment list is empty, but there are outstanding 2025 * layoutget calls, then they might be subject to a layoutrecall. 2026 */ 2027 if ((list_empty(&lo->plh_segs) || !pnfs_layout_is_valid(lo)) && 2028 atomic_read(&lo->plh_outstanding) != 0) { 2029 spin_unlock(&ino->i_lock); 2030 atomic_inc(&lo->plh_waiting); 2031 lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding, 2032 !atomic_read(&lo->plh_outstanding))); 2033 if (IS_ERR(lseg)) { 2034 atomic_dec(&lo->plh_waiting); 2035 goto out_put_layout_hdr; 2036 } 2037 if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags)) { 2038 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); 2039 lseg = NULL; 2040 if (atomic_dec_and_test(&lo->plh_waiting)) 2041 clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags); 2042 goto out_put_layout_hdr; 2043 } 2044 pnfs_put_layout_hdr(lo); 2045 goto lookup_again; 2046 } 2047 2048 /* 2049 * Because we free lsegs when sending LAYOUTRETURN, we need to wait 2050 * for LAYOUTRETURN. 2051 */ 2052 if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) { 2053 spin_unlock(&ino->i_lock); 2054 dprintk("%s wait for layoutreturn\n", __func__); 2055 lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo)); 2056 if (!IS_ERR(lseg)) { 2057 pnfs_put_layout_hdr(lo); 2058 dprintk("%s retrying\n", __func__); 2059 trace_pnfs_update_layout(ino, pos, count, iomode, lo, 2060 lseg, 2061 PNFS_UPDATE_LAYOUT_RETRY); 2062 goto lookup_again; 2063 } 2064 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2065 PNFS_UPDATE_LAYOUT_RETURN); 2066 goto out_put_layout_hdr; 2067 } 2068 2069 lseg = pnfs_find_lseg(lo, &arg, strict_iomode); 2070 if (lseg) { 2071 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2072 PNFS_UPDATE_LAYOUT_FOUND_CACHED); 2073 goto out_unlock; 2074 } 2075 2076 /* 2077 * Choose a stateid for the LAYOUTGET. If we don't have a layout 2078 * stateid, or it has been invalidated, then we must use the open 2079 * stateid. 2080 */ 2081 if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) { 2082 int status; 2083 2084 /* 2085 * The first layoutget for the file. Need to serialize per 2086 * RFC 5661 Errata 3208. 2087 */ 2088 if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, 2089 &lo->plh_flags)) { 2090 spin_unlock(&ino->i_lock); 2091 lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, 2092 NFS_LAYOUT_FIRST_LAYOUTGET, 2093 TASK_KILLABLE)); 2094 if (IS_ERR(lseg)) 2095 goto out_put_layout_hdr; 2096 pnfs_put_layout_hdr(lo); 2097 dprintk("%s retrying\n", __func__); 2098 goto lookup_again; 2099 } 2100 2101 spin_unlock(&ino->i_lock); 2102 first = true; 2103 status = nfs4_select_rw_stateid(ctx->state, 2104 iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ, 2105 NULL, &stateid, NULL); 2106 if (status != 0) { 2107 lseg = ERR_PTR(status); 2108 trace_pnfs_update_layout(ino, pos, count, 2109 iomode, lo, lseg, 2110 PNFS_UPDATE_LAYOUT_INVALID_OPEN); 2111 nfs4_schedule_stateid_recovery(server, ctx->state); 2112 pnfs_clear_first_layoutget(lo); 2113 pnfs_put_layout_hdr(lo); 2114 goto lookup_again; 2115 } 2116 spin_lock(&ino->i_lock); 2117 } else { 2118 nfs4_stateid_copy(&stateid, &lo->plh_stateid); 2119 } 2120 2121 if (pnfs_layoutgets_blocked(lo)) { 2122 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2123 PNFS_UPDATE_LAYOUT_BLOCKED); 2124 goto out_unlock; 2125 } 2126 nfs_layoutget_begin(lo); 2127 spin_unlock(&ino->i_lock); 2128 2129 _add_to_server_list(lo, server); 2130 2131 pg_offset = arg.offset & ~PAGE_MASK; 2132 if (pg_offset) { 2133 arg.offset -= pg_offset; 2134 arg.length += pg_offset; 2135 } 2136 if (arg.length != NFS4_MAX_UINT64) 2137 arg.length = PAGE_ALIGN(arg.length); 2138 2139 lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags); 2140 if (!lgp) { 2141 trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL, 2142 PNFS_UPDATE_LAYOUT_NOMEM); 2143 nfs_layoutget_end(lo); 2144 goto out_put_layout_hdr; 2145 } 2146 2147 lgp->lo = lo; 2148 pnfs_get_layout_hdr(lo); 2149 2150 lseg = nfs4_proc_layoutget(lgp, &timeout); 2151 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2152 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET); 2153 nfs_layoutget_end(lo); 2154 if (IS_ERR(lseg)) { 2155 switch(PTR_ERR(lseg)) { 2156 case -EBUSY: 2157 if (time_after(jiffies, giveup)) 2158 lseg = NULL; 2159 break; 2160 case -ERECALLCONFLICT: 2161 case -EAGAIN: 2162 break; 2163 case -ENODATA: > 2164 set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags); 2165 default: 2166 if (!nfs_error_is_fatal(PTR_ERR(lseg))) { 2167 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); 2168 lseg = NULL; 2169 } 2170 goto out_put_layout_hdr; 2171 } 2172 if (lseg) { 2173 if (first) 2174 pnfs_clear_first_layoutget(lo); 2175 trace_pnfs_update_layout(ino, pos, count, 2176 iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY); 2177 pnfs_put_layout_hdr(lo); 2178 goto lookup_again; 2179 } 2180 } else { 2181 pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode)); 2182 } 2183 2184 out_put_layout_hdr: 2185 if (first) 2186 pnfs_clear_first_layoutget(lo); 2187 trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg, 2188 PNFS_UPDATE_LAYOUT_EXIT); 2189 pnfs_put_layout_hdr(lo); 2190 out: 2191 dprintk("%s: inode %s/%llu pNFS layout segment %s for " 2192 "(%s, offset: %llu, length: %llu)\n", 2193 __func__, ino->i_sb->s_id, 2194 (unsigned long long)NFS_FILEID(ino), 2195 IS_ERR_OR_NULL(lseg) ? "not found" : "found", 2196 iomode==IOMODE_RW ? "read/write" : "read-only", 2197 (unsigned long long)pos, 2198 (unsigned long long)count); 2199 return lseg; 2200 out_unlock: 2201 spin_unlock(&ino->i_lock); 2202 goto out_put_layout_hdr; 2203 } 2204 EXPORT_SYMBOL_GPL(pnfs_update_layout); 2205 -- 0-DAY CI Kernel Test Service https://01.org/lkp
