From 07bf47fc324b0863e9c8e4bfc20a9d229ff4b595 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 11 Jul 2024 09:17:02 +0200 Subject: [PATCH] nfs: pass explicit offset/count to trace events MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit BugLink: https://bugs.launchpad.net/bugs/2083196 [ Upstream commit fada32ed6dbc748f447c8d050a961b75d946055a ] nfs_folio_length is unsafe to use without having the folio locked and a check for a NULL ->f_mapping that protects against truncations and can lead to kernel crashes. E.g. when running xfstests generic/065 with all nfs trace points enabled. Follow the model of the XFS trace points and pass in an explŃ–cit offset and length. This has the additional benefit that these values can be more accurate as some of the users touch partial folio ranges. Fixes: eb5654b3b89d ("NFS: Enable tracing of nfs_invalidate_folio() and nfs_launder_folio()") Reported-by: Chuck Lever Signed-off-by: Christoph Hellwig Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- fs/nfs/file.c | 5 +++-- fs/nfs/nfstrace.h | 36 ++++++++++++++++++++---------------- fs/nfs/read.c | 8 +++++--- fs/nfs/write.c | 10 +++++----- 4 files changed, 33 insertions(+), 26 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 8577ccf621f5..cc5229ed5cb7 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -434,7 +434,7 @@ static void nfs_invalidate_folio(struct folio *folio, size_t offset, /* Cancel any unstarted writes on this page */ nfs_wb_folio_cancel(inode, folio); folio_wait_fscache(folio); - trace_nfs_invalidate_folio(inode, folio); + trace_nfs_invalidate_folio(inode, folio_pos(folio) + offset, length); } /* @@ -502,7 +502,8 @@ static int nfs_launder_folio(struct folio *folio) folio_wait_fscache(folio); ret = nfs_wb_folio(inode, folio); - trace_nfs_launder_folio_done(inode, folio, ret); + trace_nfs_launder_folio_done(inode, folio_pos(folio), + folio_size(folio), ret); return ret; } diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h index afedb449b54f..6d45111b84fa 100644 --- a/fs/nfs/nfstrace.h +++ b/fs/nfs/nfstrace.h @@ -939,10 +939,11 @@ TRACE_EVENT(nfs_sillyrename_unlink, DECLARE_EVENT_CLASS(nfs_folio_event, TP_PROTO( const struct inode *inode, - struct folio *folio + loff_t offset, + size_t count ), - TP_ARGS(inode, folio), + TP_ARGS(inode, offset, count), TP_STRUCT__entry( __field(dev_t, dev) @@ -950,7 +951,7 @@ DECLARE_EVENT_CLASS(nfs_folio_event, __field(u64, fileid) __field(u64, version) __field(loff_t, offset) - __field(u32, count) + __field(size_t, count) ), TP_fast_assign( @@ -960,13 +961,13 @@ DECLARE_EVENT_CLASS(nfs_folio_event, __entry->fileid = nfsi->fileid; __entry->fhandle = nfs_fhandle_hash(&nfsi->fh); __entry->version = inode_peek_iversion_raw(inode); - __entry->offset = folio_file_pos(folio); - __entry->count = nfs_folio_length(folio); + __entry->offset = offset, + __entry->count = count; ), TP_printk( "fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu " - "offset=%lld count=%u", + "offset=%lld count=%zu", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->fileid, __entry->fhandle, __entry->version, @@ -978,18 +979,20 @@ DECLARE_EVENT_CLASS(nfs_folio_event, DEFINE_EVENT(nfs_folio_event, name, \ TP_PROTO( \ const struct inode *inode, \ - struct folio *folio \ + loff_t offset, \ + size_t count \ ), \ - TP_ARGS(inode, folio)) + TP_ARGS(inode, offset, count)) DECLARE_EVENT_CLASS(nfs_folio_event_done, TP_PROTO( const struct inode *inode, - struct folio *folio, + loff_t offset, + size_t count, int ret ), - TP_ARGS(inode, folio, ret), + TP_ARGS(inode, offset, count, ret), TP_STRUCT__entry( __field(dev_t, dev) @@ -998,7 +1001,7 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done, __field(u64, fileid) __field(u64, version) __field(loff_t, offset) - __field(u32, count) + __field(size_t, count) ), TP_fast_assign( @@ -1008,14 +1011,14 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done, __entry->fileid = nfsi->fileid; __entry->fhandle = nfs_fhandle_hash(&nfsi->fh); __entry->version = inode_peek_iversion_raw(inode); - __entry->offset = folio_file_pos(folio); - __entry->count = nfs_folio_length(folio); + __entry->offset = offset, + __entry->count = count, __entry->ret = ret; ), TP_printk( "fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu " - "offset=%lld count=%u ret=%d", + "offset=%lld count=%zu ret=%d", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->fileid, __entry->fhandle, __entry->version, @@ -1027,10 +1030,11 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done, DEFINE_EVENT(nfs_folio_event_done, name, \ TP_PROTO( \ const struct inode *inode, \ - struct folio *folio, \ + loff_t offset, \ + size_t count, \ int ret \ ), \ - TP_ARGS(inode, folio, ret)) + TP_ARGS(inode, offset, count, ret)) DEFINE_NFS_FOLIO_EVENT(nfs_aop_readpage); DEFINE_NFS_FOLIO_EVENT_DONE(nfs_aop_readpage_done); diff --git a/fs/nfs/read.c b/fs/nfs/read.c index a142287d86f6..88e6a78d37fb 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -332,13 +332,15 @@ out: int nfs_read_folio(struct file *file, struct folio *folio) { struct inode *inode = file_inode(file); + loff_t pos = folio_pos(folio); + size_t len = folio_size(folio); struct nfs_pageio_descriptor pgio; struct nfs_open_context *ctx; int ret; - trace_nfs_aop_readpage(inode, folio); + trace_nfs_aop_readpage(inode, pos, len); nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); - task_io_account_read(folio_size(folio)); + task_io_account_read(len); /* * Try to flush any pending writes to the file.. @@ -381,7 +383,7 @@ int nfs_read_folio(struct file *file, struct folio *folio) out_put: put_nfs_open_context(ctx); out: - trace_nfs_aop_readpage_done(inode, folio, ret); + trace_nfs_aop_readpage_done(inode, pos, len, ret); return ret; out_unlock: folio_unlock(folio); diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 5d9dc6c05325..7382c1135289 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -2077,17 +2077,17 @@ int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio) */ int nfs_wb_folio(struct inode *inode, struct folio *folio) { - loff_t range_start = folio_file_pos(folio); - loff_t range_end = range_start + (loff_t)folio_size(folio) - 1; + loff_t range_start = folio_pos(folio); + size_t len = folio_size(folio); struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, .range_start = range_start, - .range_end = range_end, + .range_end = range_start + len - 1, }; int ret; - trace_nfs_writeback_folio(inode, folio); + trace_nfs_writeback_folio(inode, range_start, len); for (;;) { folio_wait_writeback(folio); @@ -2105,7 +2105,7 @@ int nfs_wb_folio(struct inode *inode, struct folio *folio) goto out_error; } out_error: - trace_nfs_writeback_folio_done(inode, folio, ret); + trace_nfs_writeback_folio_done(inode, range_start, len, ret); return ret; }