From 110cb2d2f9326030f13b7ec85d6d482934ea5462 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 4 Oct 2021 10:10:16 -0400 Subject: NFS: Instrument i_size_write() Generate a trace event whenever the NFS client modifies the size of a file. These new events aid troubleshooting workloads that trigger races around size updates. There are four new trace points, all named nfs_size_something so they are easy to grep for or enable as a group with a single glob. Size updated on the server: kworker/u24:10-194 [010] 369.939174: nfs_size_update: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899344277980615 cursize=250471 newsize=172083 Server-side size update reported via NFSv3 WCC attributes: fsx-1387 [006] 380.760686: nfs_size_wcc: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899355909932456 cursize=146792 newsize=171216 File has been truncated locally: fsx-1387 [007] 369.437421: nfs_size_truncate: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899231200117272 cursize=215244 newsize=0 File has been extended locally: fsx-1387 [007] 369.439213: nfs_size_grow: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899343704248410 cursize=258048 newsize=262144 Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 9 +++------ fs/nfs/nfstrace.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nfs/write.c | 1 + 3 files changed, 54 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 3bd0ae438663..a10572f278e6 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -671,6 +671,7 @@ static int nfs_vmtruncate(struct inode * inode, loff_t offset) if (err) goto out; + trace_nfs_size_truncate(inode, offset); i_size_write(inode, offset); /* Optimisation */ if (offset == 0) @@ -1456,6 +1457,7 @@ static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr) && (fattr->valid & NFS_ATTR_FATTR_SIZE) && i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size) && !nfs_have_writebacks(inode)) { + trace_nfs_size_wcc(inode, fattr->size); i_size_write(inode, nfs_size_to_loff_t(fattr->size)); } } @@ -2100,16 +2102,11 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) /* Do we perhaps have any outstanding writes, or has * the file grown beyond our last write? */ if (!nfs_have_writebacks(inode) || new_isize > cur_isize) { + trace_nfs_size_update(inode, new_isize); i_size_write(inode, new_isize); if (!have_writers) invalid |= NFS_INO_INVALID_DATA; } - dprintk("NFS: isize change on server for file %s/%ld " - "(%Ld to %Ld)\n", - inode->i_sb->s_id, - inode->i_ino, - (long long)cur_isize, - (long long)new_isize); } if (new_isize == 0 && !(fattr->valid & (NFS_ATTR_FATTR_SPACE_USED | diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h index 589f32fdbe63..44fd016a8e65 100644 --- a/fs/nfs/nfstrace.h +++ b/fs/nfs/nfstrace.h @@ -231,6 +231,56 @@ TRACE_EVENT(nfs_access_exit, ) ); +DECLARE_EVENT_CLASS(nfs_update_size_class, + TP_PROTO( + const struct inode *inode, + loff_t new_size + ), + + TP_ARGS(inode, new_size), + + TP_STRUCT__entry( + __field(dev_t, dev) + __field(u32, fhandle) + __field(u64, fileid) + __field(u64, version) + __field(loff_t, cur_size) + __field(loff_t, new_size) + ), + + TP_fast_assign( + const struct nfs_inode *nfsi = NFS_I(inode); + + __entry->dev = inode->i_sb->s_dev; + __entry->fhandle = nfs_fhandle_hash(&nfsi->fh); + __entry->fileid = nfsi->fileid; + __entry->version = inode_peek_iversion_raw(inode); + __entry->cur_size = i_size_read(inode); + __entry->new_size = new_size; + ), + + TP_printk( + "fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu cursize=%lld newsize=%lld", + MAJOR(__entry->dev), MINOR(__entry->dev), + (unsigned long long)__entry->fileid, + __entry->fhandle, __entry->version, + __entry->cur_size, __entry->new_size + ) +); + +#define DEFINE_NFS_UPDATE_SIZE_EVENT(name) \ + DEFINE_EVENT(nfs_update_size_class, nfs_size_##name, \ + TP_PROTO( \ + const struct inode *inode, \ + loff_t new_size \ + ), \ + TP_ARGS(inode, new_size)) + +DEFINE_NFS_UPDATE_SIZE_EVENT(truncate); +DEFINE_NFS_UPDATE_SIZE_EVENT(wcc); +DEFINE_NFS_UPDATE_SIZE_EVENT(update); +DEFINE_NFS_UPDATE_SIZE_EVENT(grow); + #define show_lookup_flags(flags) \ __print_flags(flags, "|", \ { LOOKUP_FOLLOW, "FOLLOW" }, \ diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 773ea2c8504d..b89d5ef3af0e 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -288,6 +288,7 @@ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int c end = page_file_offset(page) + ((loff_t)offset+count); if (i_size >= end) goto out; + trace_nfs_size_grow(inode, end); i_size_write(inode, end); NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE; nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); -- cgit v1.2.3