From 1b15129d9af7723878d433d66b9a3fe2acffabc4 Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Fri, 9 Oct 2026 18:38:29 +0800 Subject: [PATCH] ext4: add tracepoints for EOF block zeroing and disksize-grow I/O Add tracepoints to track the disksize-grow-pending lifecycle in the writeback path and the block-zero-EOF entry point: - ext4_iomap_wb_disksize_pending_submit: ioend is marked as DISKSIZE_GROW_IO in ext4_iomap_writeback_submit(). - ext4_iomap_wb_disksize_pending_complete: ioend of type DISKSIZE_GROW_IO completes in ext4_iomap_finish_ioend(). - ext4_iomap_wb_disksize_pending_wait: ioend worker waits for the pending zeroed EOF block to complete. - ext4_iomap_wb_update_disksize: i_disksize is advanced in ext4_iomap_wb_update_disksize, including the new value and whether the update is a disksize-grow completion. - ext4_block_zero_eof: ext4_block_zero_eof is called with the range and zeroing outcome, capturing the producer-side entry point. Together with the previous mark/clear/wait tracepoints, these cover the full lifetime of the disksize-grow-pending state. Signed-off-by: Zhang Yi Tested-by: syzbot@syzkaller.appspotmail.com Link: https://patch.msgid.link/20261009103831.2978767-1-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/inode.c | 3 + fs/ext4/page-io.c | 11 ++- include/trace/events/ext4.h | 129 ++++++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index cb2b089d4419..8cb6551684b3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4417,6 +4417,8 @@ static int ext4_iomap_writeback_submit(struct iomap_writepage_ctx *wpc, round_down(ioend->io_offset, blocksize) <= pstart && round_up(ioend->io_offset + ioend->io_size, blocksize) >= pstart + plen) { + trace_ext4_iomap_wb_disksize_pending_submit(inode, + ioend->io_offset, ioend->io_size); ioend->io_bio.bi_end_io = ext4_iomap_end_bio; ioend->io_private = (void *)EXT4_IOMAP_IOEND_DISKSIZE_GROW_IO; } @@ -5033,6 +5035,7 @@ int ext4_block_zero_eof(struct inode *inode, loff_t from, loff_t end) return err; } + trace_ext4_block_zero_eof(inode, from, length, did_zero, zero_written); return 0; } diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 4f1176b9332f..734d856a6d47 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -31,6 +31,8 @@ #include "xattr.h" #include "acl.h" +#include + static struct kmem_cache *io_end_cachep; static struct kmem_cache *io_end_vec_cachep; @@ -574,6 +576,7 @@ static void ext4_iomap_wb_disksize_pending_wait(struct inode *inode, if (!plen || pos < pstart + plen) return; + trace_ext4_iomap_wb_disksize_pending_wait(inode, pos, size); ext4_iomap_wait_disksize_pending(inode); } @@ -617,8 +620,11 @@ static int ext4_iomap_wb_update_disksize(handle_t *handle, struct inode *inode, * after the data has been persisted. */ new_disksize = is_disksize_grow ? i_size : min(end, i_size); - if (new_disksize > ei->i_disksize) + if (new_disksize > ei->i_disksize) { + trace_ext4_iomap_wb_update_disksize(inode, end, i_size, + ei->i_disksize, new_disksize, is_disksize_grow); WRITE_ONCE(ei->i_disksize, new_disksize); + } up_write(&ei->i_data_sem); ret = ext4_mark_inode_dirty(handle, inode); if (ret) @@ -641,6 +647,9 @@ static void ext4_iomap_finish_ioend(struct iomap_ioend *ioend) int ret, err; ret = blk_status_to_errno(ioend->io_bio.bi_status); + if (is_disksize_grow) + trace_ext4_iomap_wb_disksize_pending_complete(ioend->io_inode, + ioend->io_offset, ioend->io_size, ret); if (unlikely(ret)) { if (test_opt(sb, DATA_ERR_ABORT) && !ext4_emergency_state(sb)) jbd2_journal_abort(EXT4_SB(sb)->s_journal, ret); diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index d33456d06b00..92048da9dae4 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -3237,6 +3237,135 @@ DEFINE_EVENT(ext4_iomap_disksize_pending, ext4_iomap_wait_disksize_pending, TP_ARGS(inode) ); +/* disksize pending I/O tracepoints for iomap Buffered I/O path */ +DECLARE_EVENT_CLASS(ext4_iomap_wb_disksize_pending, + TP_PROTO(struct inode *inode, loff_t io_offset, size_t io_size), + TP_ARGS(inode, io_offset, io_size), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(u64, ino) + __field(loff_t, io_offset) + __field(size_t, io_size) + __field(loff_t, i_size) + __field(loff_t, i_disksize) + ), + TP_fast_assign( + __entry->dev = inode->i_sb->s_dev; + __entry->ino = inode->i_ino; + __entry->io_offset = io_offset; + __entry->io_size = io_size; + __entry->i_size = i_size_read(inode); + __entry->i_disksize = READ_ONCE(EXT4_I(inode)->i_disksize); + ), + TP_printk("dev %d:%d ino %llu io_offset %lld io_size %zu i_size %lld i_disksize %lld", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->ino, __entry->io_offset, __entry->io_size, + __entry->i_size, __entry->i_disksize) +); + +DEFINE_EVENT(ext4_iomap_wb_disksize_pending, + ext4_iomap_wb_disksize_pending_submit, + TP_PROTO(struct inode *inode, loff_t io_offset, size_t io_size), + TP_ARGS(inode, io_offset, io_size) +); + +DEFINE_EVENT(ext4_iomap_wb_disksize_pending, + ext4_iomap_wb_disksize_pending_wait, + TP_PROTO(struct inode *inode, loff_t io_offset, size_t io_size), + TP_ARGS(inode, io_offset, io_size) +); + +TRACE_EVENT(ext4_iomap_wb_disksize_pending_complete, + TP_PROTO(struct inode *inode, loff_t io_offset, size_t io_size, + int ret), + TP_ARGS(inode, io_offset, io_size, ret), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(u64, ino) + __field(loff_t, io_offset) + __field(size_t, io_size) + __field(loff_t, i_size) + __field(loff_t, i_disksize) + __field(int, ret) + ), + TP_fast_assign( + __entry->dev = inode->i_sb->s_dev; + __entry->ino = inode->i_ino; + __entry->io_offset = io_offset; + __entry->io_size = io_size; + __entry->i_size = i_size_read(inode); + __entry->i_disksize = READ_ONCE(EXT4_I(inode)->i_disksize); + __entry->ret = ret; + ), + TP_printk("dev %d:%d ino %llu io_offset %lld io_size %zu ret %d i_size %lld i_disksize %lld", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->ino, __entry->io_offset, __entry->io_size, + __entry->ret, __entry->i_size, __entry->i_disksize) +); + +/* i_disksize update tracepoint */ +TRACE_EVENT(ext4_iomap_wb_update_disksize, + TP_PROTO(struct inode *inode, loff_t end, loff_t i_size, + loff_t i_disksize, loff_t new_disksize, + bool is_disksize_grow), + TP_ARGS(inode, end, i_size, i_disksize, new_disksize, + is_disksize_grow), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(u64, ino) + __field(loff_t, end) + __field(loff_t, i_size) + __field(loff_t, i_disksize) + __field(loff_t, new_disksize) + __field(bool, is_disksize_grow) + ), + TP_fast_assign( + __entry->dev = inode->i_sb->s_dev; + __entry->ino = inode->i_ino; + __entry->end = end; + __entry->i_size = i_size; + __entry->i_disksize = i_disksize; + __entry->new_disksize = new_disksize; + __entry->is_disksize_grow = is_disksize_grow; + ), + TP_printk("dev %d:%d ino %llu end %lld i_size %lld i_disksize %lld new_disksize %lld is_disksize_grow %d", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->ino, __entry->end, __entry->i_size, + __entry->i_disksize, __entry->new_disksize, + __entry->is_disksize_grow) +); + +/* Block zero EOF tracepoint */ +TRACE_EVENT(ext4_block_zero_eof, + TP_PROTO(struct inode *inode, loff_t from, loff_t length, + bool did_zero, bool zero_written), + TP_ARGS(inode, from, length, did_zero, zero_written), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(u64, ino) + __field(loff_t, from) + __field(loff_t, length) + __field(loff_t, i_size) + __field(loff_t, i_disksize) + __field(bool, did_zero) + __field(bool, zero_written) + ), + TP_fast_assign( + __entry->dev = inode->i_sb->s_dev; + __entry->ino = inode->i_ino; + __entry->from = from; + __entry->length = length; + __entry->i_size = inode->i_size; + __entry->i_disksize = READ_ONCE(EXT4_I(inode)->i_disksize); + __entry->did_zero = did_zero; + __entry->zero_written = zero_written; + ), + TP_printk("dev %d:%d ino %llu zero EOF from %lld length %lld i_size %lld i_disksize %lld did_zero %d zero_written %d", + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->ino, + __entry->from, __entry->length, __entry->i_size, + __entry->i_disksize, __entry->did_zero, __entry->zero_written) +); + #endif /* _TRACE_EXT4_H */ /* This part must be outside protection */