From cd35b6cb46649750b7dbd0df0e2d767415d8917b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 1 Apr 2025 15:02:21 -0700 Subject: [PATCH 1/2] nfs: add missing selections of CONFIG_CRC32 nfs.ko, nfsd.ko, and lockd.ko all use crc32_le(), which is available only when CONFIG_CRC32 is enabled. But the only NFS kconfig option that selected CONFIG_CRC32 was CONFIG_NFS_DEBUG, which is client-specific and did not actually guard the use of crc32_le() even on the client. The code worked around this bug by only actually calling crc32_le() when CONFIG_CRC32 is built-in, instead hard-coding '0' in other cases. This avoided randconfig build errors, and in real kernels the fallback code was unlikely to be reached since CONFIG_CRC32 is 'default y'. But, this really needs to just be done properly, especially now that I'm planning to update CONFIG_CRC32 to not be 'default y'. Therefore, make CONFIG_NFS_FS, CONFIG_NFSD, and CONFIG_LOCKD select CONFIG_CRC32. Then remove the fallback code that becomes unnecessary, as well as the selection of CONFIG_CRC32 from CONFIG_NFS_DEBUG. Fixes: 1264a2f053a3 ("NFS: refactor code for calculating the crc32 hash of a filehandle") Signed-off-by: Eric Biggers Acked-by: Anna Schumaker Signed-off-by: Chuck Lever --- fs/Kconfig | 1 + fs/nfs/Kconfig | 2 +- fs/nfs/internal.h | 7 ------- fs/nfs/nfs4session.h | 4 ---- fs/nfsd/Kconfig | 1 + fs/nfsd/nfsfh.h | 7 ------- include/linux/nfs.h | 7 ------- 7 files changed, 3 insertions(+), 26 deletions(-) diff --git a/fs/Kconfig b/fs/Kconfig index 64d420e3c4758..8fd1011f7d628 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -368,6 +368,7 @@ config GRACE_PERIOD config LOCKD tristate depends on FILE_LOCKING + select CRC32 select GRACE_PERIOD config LOCKD_V4 diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index d3f76101ad4b9..07932ce9246c1 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -2,6 +2,7 @@ config NFS_FS tristate "NFS client support" depends on INET && FILE_LOCKING && MULTIUSER + select CRC32 select LOCKD select SUNRPC select NFS_COMMON @@ -196,7 +197,6 @@ config NFS_USE_KERNEL_DNS config NFS_DEBUG bool depends on NFS_FS && SUNRPC_DEBUG - select CRC32 default y config NFS_DISABLE_UDP_SUPPORT diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index fae2c7ae4acc2..59bb4d0338f39 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -899,18 +899,11 @@ u64 nfs_timespec_to_change_attr(const struct timespec64 *ts) return ((u64)ts->tv_sec << 30) + ts->tv_nsec; } -#ifdef CONFIG_CRC32 static inline u32 nfs_stateid_hash(const nfs4_stateid *stateid) { return ~crc32_le(0xFFFFFFFF, &stateid->other[0], NFS4_STATEID_OTHER_SIZE); } -#else -static inline u32 nfs_stateid_hash(nfs4_stateid *stateid) -{ - return 0; -} -#endif static inline bool nfs_error_is_fatal(int err) { diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h index 351616c61df54..f9c291e2165cd 100644 --- a/fs/nfs/nfs4session.h +++ b/fs/nfs/nfs4session.h @@ -148,16 +148,12 @@ static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst, memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN); } -#ifdef CONFIG_CRC32 /* * nfs_session_id_hash - calculate the crc32 hash for the session id * @session - pointer to session */ #define nfs_session_id_hash(sess_id) \ (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data))) -#else -#define nfs_session_id_hash(session) (0) -#endif #else /* defined(CONFIG_NFS_V4_1) */ static inline int nfs4_init_session(struct nfs_client *clp) diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig index 792d3fed1b45f..731a88f6313eb 100644 --- a/fs/nfsd/Kconfig +++ b/fs/nfsd/Kconfig @@ -4,6 +4,7 @@ config NFSD depends on INET depends on FILE_LOCKING depends on FSNOTIFY + select CRC32 select LOCKD select SUNRPC select EXPORTFS diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h index 876152a91f122..5103c2f4d2253 100644 --- a/fs/nfsd/nfsfh.h +++ b/fs/nfsd/nfsfh.h @@ -267,7 +267,6 @@ static inline bool fh_fsid_match(const struct knfsd_fh *fh1, return true; } -#ifdef CONFIG_CRC32 /** * knfsd_fh_hash - calculate the crc32 hash for the filehandle * @fh - pointer to filehandle @@ -279,12 +278,6 @@ static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh) { return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size); } -#else -static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh) -{ - return 0; -} -#endif /** * fh_clear_pre_post_attrs - Reset pre/post attributes diff --git a/include/linux/nfs.h b/include/linux/nfs.h index 9ad727ddfedb3..0906a0b40c6aa 100644 --- a/include/linux/nfs.h +++ b/include/linux/nfs.h @@ -55,7 +55,6 @@ enum nfs3_stable_how { NFS_INVALID_STABLE_HOW = -1 }; -#ifdef CONFIG_CRC32 /** * nfs_fhandle_hash - calculate the crc32 hash for the filehandle * @fh - pointer to filehandle @@ -67,10 +66,4 @@ static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh) { return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size); } -#else /* CONFIG_CRC32 */ -static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh) -{ - return 0; -} -#endif /* CONFIG_CRC32 */ #endif /* _LINUX_NFS_H */ From a1d14d931bf700c1025db8c46d6731aa5cf440f9 Mon Sep 17 00:00:00 2001 From: Li Lingfeng Date: Thu, 10 Apr 2025 09:57:08 +0800 Subject: [PATCH 2/2] nfsd: decrease sc_count directly if fail to queue dl_recall A deadlock warning occurred when invoking nfs4_put_stid following a failed dl_recall queue operation: T1 T2 nfs4_laundromat nfs4_get_client_reaplist nfs4_anylock_blockers __break_lease spin_lock // ctx->flc_lock spin_lock // clp->cl_lock nfs4_lockowner_has_blockers locks_owner_has_blockers spin_lock // flctx->flc_lock nfsd_break_deleg_cb nfsd_break_one_deleg nfs4_put_stid refcount_dec_and_lock spin_lock // clp->cl_lock When a file is opened, an nfs4_delegation is allocated with sc_count initialized to 1, and the file_lease holds a reference to the delegation. The file_lease is then associated with the file through kernel_setlease. The disassociation is performed in nfsd4_delegreturn via the following call chain: nfsd4_delegreturn --> destroy_delegation --> destroy_unhashed_deleg --> nfs4_unlock_deleg_lease --> kernel_setlease --> generic_delete_lease The corresponding sc_count reference will be released after this disassociation. Since nfsd_break_one_deleg executes while holding the flc_lock, the disassociation process becomes blocked when attempting to acquire flc_lock in generic_delete_lease. This means: 1) sc_count in nfsd_break_one_deleg will not be decremented to 0; 2) The nfs4_put_stid called by nfsd_break_one_deleg will not attempt to acquire cl_lock; 3) Consequently, no deadlock condition is created. Given that sc_count in nfsd_break_one_deleg remains non-zero, we can safely perform refcount_dec on sc_count directly. This approach effectively avoids triggering deadlock warnings. Fixes: 230ca758453c ("nfsd: put dl_stid if fail to queue dl_recall") Signed-off-by: Li Lingfeng Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- fs/nfsd/nfs4state.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 2041268b398a4..59a693f22452b 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -5430,7 +5430,7 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp) queued = nfsd4_run_cb(&dp->dl_recall); WARN_ON_ONCE(!queued); if (!queued) - nfs4_put_stid(&dp->dl_stid); + refcount_dec(&dp->dl_stid.sc_count); } /* Called from break_lease() with flc_lock held. */