From 1888635532fbbd6be4a4368621085c3a197279f8 Mon Sep 17 00:00:00 2001 From: Julian Sun Date: Tue, 30 Sep 2025 16:53:15 +0800 Subject: writeback: Wake up waiting tasks when finishing the writeback of a chunk. Writing back a large number of pages can take a lots of time. This issue is exacerbated when the underlying device is slow or subject to block layer rate limiting, which in turn triggers unexpected hung task warnings. We can trigger a wake-up once a chunk has been written back and the waiting time for writeback exceeds half of sysctl_hung_task_timeout_secs. This action allows the hung task detector to be aware of the writeback progress, thereby eliminating these unexpected hung task warnings. This patch has passed the xfstests 'check -g quick' test based on ext4, with no additional failures introduced. Signed-off-by: Julian Sun Reviewed-by: Jan Kara Suggested-by: Peter Zijlstra Signed-off-by: Christian Brauner --- include/linux/backing-dev-defs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index c5c9d89c73ed..c8aa749790b1 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -63,6 +63,7 @@ enum wb_reason { struct wb_completion { atomic_t cnt; wait_queue_head_t *waitq; + unsigned long progress_stamp; /* The jiffies when slow progress is detected */ }; #define __WB_COMPLETION_INIT(_waitq) \ -- cgit v1.2.3 From d6e6215907640801b1f407dc9e871b19ca5a3805 Mon Sep 17 00:00:00 2001 From: Julian Sun Date: Tue, 30 Sep 2025 15:18:29 +0800 Subject: writeback: Add logging for slow writeback (exceeds sysctl_hung_task_timeout_secs) When a writeback work lasts for sysctl_hung_task_timeout_secs, we want to identify that there are tasks waiting for a long time-this helps us pinpoint potential issues. Additionally, recording the starting jiffies is useful when debugging a crashed vmcore. Signed-off-by: Julian Sun Signed-off-by: Christian Brauner --- fs/fs-writeback.c | 17 +++++++++++++++-- include/linux/backing-dev-defs.h | 1 + 2 files changed, 16 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 61a980a06cee..e76192d140e3 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -201,6 +201,19 @@ static void wb_queue_work(struct bdi_writeback *wb, spin_unlock_irq(&wb->work_lock); } +static bool wb_wait_for_completion_cb(struct wb_completion *done) +{ + unsigned long waited_secs = (jiffies - done->wait_start) / HZ; + + done->progress_stamp = jiffies; + if (waited_secs > sysctl_hung_task_timeout_secs) + pr_info("INFO: The task %s:%d has been waiting for writeback " + "completion for more than %lu seconds.", + current->comm, current->pid, waited_secs); + + return !atomic_read(&done->cnt); +} + /** * wb_wait_for_completion - wait for completion of bdi_writeback_works * @done: target wb_completion @@ -213,9 +226,9 @@ static void wb_queue_work(struct bdi_writeback *wb, */ void wb_wait_for_completion(struct wb_completion *done) { + done->wait_start = jiffies; atomic_dec(&done->cnt); /* put down the initial count */ - wait_event(*done->waitq, - ({ done->progress_stamp = jiffies; !atomic_read(&done->cnt); })); + wait_event(*done->waitq, wb_wait_for_completion_cb(done)); } #ifdef CONFIG_CGROUP_WRITEBACK diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index c8aa749790b1..610ef62b6a32 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -64,6 +64,7 @@ struct wb_completion { atomic_t cnt; wait_queue_head_t *waitq; unsigned long progress_stamp; /* The jiffies when slow progress is detected */ + unsigned long wait_start; /* The jiffies when waiting for the writeback work to finish */ }; #define __WB_COMPLETION_INIT(_waitq) \ -- cgit v1.2.3 From 7fabcb7fbabbcddd9dc42dbe4c92d18ce3e54283 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Oct 2025 10:04:17 +0200 Subject: mm,btrfs: add a filemap_flush_nr helper Abstract out the btrfs-specific behavior of kicking off I/O on a number of pages on an address_space into a well-defined helper. Note: there is no kerneldoc comment for the new function because it is not part of the public API. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251024080431.324236-7-hch@lst.de Reviewed-by: David Hildenbrand Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/btrfs/inode.c | 13 ++----------- include/linux/pagemap.h | 1 + mm/filemap.c | 22 ++++++++++++++++++++++ 3 files changed, 25 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index b97d6c1f7772..d12b8116adde 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8752,19 +8752,10 @@ static int start_delalloc_inodes(struct btrfs_root *root, long *nr_to_write, btrfs_queue_work(root->fs_info->flush_workers, &work->work); } else { - struct writeback_control wbc = { - .nr_to_write = *nr_to_write, - .sync_mode = WB_SYNC_NONE, - .range_start = 0, - .range_end = LLONG_MAX, - }; - - ret = filemap_fdatawrite_wbc(tmp_inode->i_mapping, - &wbc); + ret = filemap_flush_nr(tmp_inode->i_mapping, + nr_to_write); btrfs_add_delayed_iput(inode); - if (*nr_to_write != LONG_MAX) - *nr_to_write = wbc.nr_to_write; if (ret || *nr_to_write <= 0) goto out; } diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 09b581c1d878..cebdf160d3dd 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -38,6 +38,7 @@ int filemap_invalidate_pages(struct address_space *mapping, int write_inode_now(struct inode *, int sync); int filemap_fdatawrite(struct address_space *); int filemap_flush(struct address_space *); +int filemap_flush_nr(struct address_space *mapping, long *nr_to_write); int filemap_fdatawait_keep_errors(struct address_space *mapping); int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); int filemap_fdatawait_range_keep_errors(struct address_space *mapping, diff --git a/mm/filemap.c b/mm/filemap.c index 99d6919af60d..e344b79a012d 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -474,6 +474,28 @@ int filemap_flush(struct address_space *mapping) } EXPORT_SYMBOL(filemap_flush); +/* + * Start writeback on @nr_to_write pages from @mapping. No one but the existing + * btrfs caller should be using this. Talk to linux-mm if you think adding a + * new caller is a good idea. + */ +int filemap_flush_nr(struct address_space *mapping, long *nr_to_write) +{ + struct writeback_control wbc = { + .nr_to_write = *nr_to_write, + .sync_mode = WB_SYNC_NONE, + .range_start = 0, + .range_end = LLONG_MAX, + }; + int ret; + + ret = filemap_fdatawrite_wbc(mapping, &wbc); + if (!ret) + *nr_to_write = wbc.nr_to_write; + return ret; +} +EXPORT_SYMBOL_FOR_MODULES(filemap_flush_nr, "btrfs"); + /** * filemap_range_has_page - check if a page exists in range. * @mapping: address space within which to check -- cgit v1.2.3 From 1bcb413d0cd80efb386751910036a93147fd8dbc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Oct 2025 10:04:19 +0200 Subject: mm: remove filemap_fdatawrite_wbc Replace filemap_fdatawrite_wbc, which exposes a writeback_control to the callers with a filemap_writeback helper that takes all the possible arguments and declares the writeback_control itself. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251024080431.324236-9-hch@lst.de Reviewed-by: David Hildenbrand Reviewed-by: Jan Kara Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Christian Brauner --- fs/fs-writeback.c | 6 +++--- include/linux/pagemap.h | 2 -- mm/filemap.c | 54 +++++++++++++++++-------------------------------- 3 files changed, 21 insertions(+), 41 deletions(-) (limited to 'include/linux') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index e76192d140e3..4448de35ec8b 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -822,9 +822,9 @@ static void wbc_attach_and_unlock_inode(struct writeback_control *wbc, * @wbc: writeback_control of interest * @inode: target inode * - * This function is to be used by __filemap_fdatawrite_range(), which is an - * alternative entry point into writeback code, and first ensures @inode is - * associated with a bdi_writeback and attaches it to @wbc. + * This function is to be used by filemap_writeback(), which is an alternative + * entry point into writeback code, and first ensures @inode is associated with + * a bdi_writeback and attaches it to @wbc. */ void wbc_attach_fdatawrite_inode(struct writeback_control *wbc, struct inode *inode) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index cebdf160d3dd..678d8ae23d01 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -60,8 +60,6 @@ int filemap_fdatawrite_range(struct address_space *mapping, loff_t start, loff_t end); int filemap_check_errors(struct address_space *mapping); void __filemap_set_wb_err(struct address_space *mapping, int err); -int filemap_fdatawrite_wbc(struct address_space *mapping, - struct writeback_control *wbc); int kiocb_write_and_wait(struct kiocb *iocb, size_t count); static inline int filemap_write_and_wait(struct address_space *mapping) diff --git a/mm/filemap.c b/mm/filemap.c index 3d4c4a96c586..7126d0587c94 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -366,31 +366,30 @@ static int filemap_check_and_keep_errors(struct address_space *mapping) return 0; } -/** - * filemap_fdatawrite_wbc - start writeback on mapping dirty pages in range - * @mapping: address space structure to write - * @wbc: the writeback_control controlling the writeout - * - * Call writepages on the mapping using the provided wbc to control the - * writeout. - * - * Return: %0 on success, negative error code otherwise. - */ -int filemap_fdatawrite_wbc(struct address_space *mapping, - struct writeback_control *wbc) +static int filemap_writeback(struct address_space *mapping, loff_t start, + loff_t end, enum writeback_sync_modes sync_mode, + long *nr_to_write) { + struct writeback_control wbc = { + .sync_mode = sync_mode, + .nr_to_write = nr_to_write ? *nr_to_write : LONG_MAX, + .range_start = start, + .range_end = end, + }; int ret; if (!mapping_can_writeback(mapping) || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) return 0; - wbc_attach_fdatawrite_inode(wbc, mapping->host); - ret = do_writepages(mapping, wbc); - wbc_detach_inode(wbc); + wbc_attach_fdatawrite_inode(&wbc, mapping->host); + ret = do_writepages(mapping, &wbc); + wbc_detach_inode(&wbc); + + if (!ret && nr_to_write) + *nr_to_write = wbc.nr_to_write; return ret; } -EXPORT_SYMBOL(filemap_fdatawrite_wbc); /** * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range @@ -412,14 +411,7 @@ EXPORT_SYMBOL(filemap_fdatawrite_wbc); int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, loff_t end, int sync_mode) { - struct writeback_control wbc = { - .sync_mode = sync_mode, - .nr_to_write = LONG_MAX, - .range_start = start, - .range_end = end, - }; - - return filemap_fdatawrite_wbc(mapping, &wbc); + return filemap_writeback(mapping, start, end, sync_mode, NULL); } int filemap_fdatawrite_range(struct address_space *mapping, loff_t start, @@ -475,18 +467,8 @@ EXPORT_SYMBOL(filemap_flush); */ int filemap_flush_nr(struct address_space *mapping, long *nr_to_write) { - struct writeback_control wbc = { - .nr_to_write = *nr_to_write, - .sync_mode = WB_SYNC_NONE, - .range_start = 0, - .range_end = LLONG_MAX, - }; - int ret; - - ret = filemap_fdatawrite_wbc(mapping, &wbc); - if (!ret) - *nr_to_write = wbc.nr_to_write; - return ret; + return filemap_writeback(mapping, 0, LLONG_MAX, WB_SYNC_NONE, + nr_to_write); } EXPORT_SYMBOL_FOR_MODULES(filemap_flush_nr, "btrfs"); -- cgit v1.2.3 From 45cbce5b8877f339b72548f60aa97634044c255c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Oct 2025 10:04:20 +0200 Subject: mm: remove __filemap_fdatawrite_range Use filemap_fdatawrite_range and filemap_fdatawrite_range_kick instead of the low-level __filemap_fdatawrite_range that requires the caller to know the internals of the writeback_control structure and remove __filemap_fdatawrite_range now that it is trivial and only two callers would be left. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251024080431.324236-10-hch@lst.de Reviewed-by: Jan Kara Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Christian Brauner --- fs/sync.c | 11 +++++------ include/linux/pagemap.h | 2 -- mm/fadvise.c | 3 +-- mm/filemap.c | 25 +++++++------------------ 4 files changed, 13 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/fs/sync.c b/fs/sync.c index 2955cd4c77a3..6d8b04e04c3c 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -280,14 +280,13 @@ int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, } if (flags & SYNC_FILE_RANGE_WRITE) { - int sync_mode = WB_SYNC_NONE; - if ((flags & SYNC_FILE_RANGE_WRITE_AND_WAIT) == SYNC_FILE_RANGE_WRITE_AND_WAIT) - sync_mode = WB_SYNC_ALL; - - ret = __filemap_fdatawrite_range(mapping, offset, endbyte, - sync_mode); + ret = filemap_fdatawrite_range(mapping, offset, + endbyte); + else + ret = filemap_fdatawrite_range_kick(mapping, offset, + endbyte); if (ret < 0) goto out; } diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 678d8ae23d01..d0a7dd43c835 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -54,8 +54,6 @@ static inline int filemap_fdatawait(struct address_space *mapping) bool filemap_range_has_page(struct address_space *, loff_t lstart, loff_t lend); int filemap_write_and_wait_range(struct address_space *mapping, loff_t lstart, loff_t lend); -int __filemap_fdatawrite_range(struct address_space *mapping, - loff_t start, loff_t end, int sync_mode); int filemap_fdatawrite_range(struct address_space *mapping, loff_t start, loff_t end); int filemap_check_errors(struct address_space *mapping); diff --git a/mm/fadvise.c b/mm/fadvise.c index 588fe76c5a14..f1be619f0e58 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -111,8 +111,7 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice) spin_unlock(&file->f_lock); break; case POSIX_FADV_DONTNEED: - __filemap_fdatawrite_range(mapping, offset, endbyte, - WB_SYNC_NONE); + filemap_fdatawrite_range_kick(mapping, offset, endbyte); /* * First and last FULL page! Partial pages are deliberately diff --git a/mm/filemap.c b/mm/filemap.c index 7126d0587c94..f90f5bb2b825 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -392,32 +392,23 @@ static int filemap_writeback(struct address_space *mapping, loff_t start, } /** - * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range + * filemap_fdatawrite_range - start writeback on mapping dirty pages in range * @mapping: address space structure to write * @start: offset in bytes where the range starts * @end: offset in bytes where the range ends (inclusive) - * @sync_mode: enable synchronous operation * * Start writeback against all of a mapping's dirty pages that lie * within the byte offsets inclusive. * - * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as - * opposed to a regular memory cleansing writeback. The difference between - * these two operations is that if a dirty page/buffer is encountered, it must - * be waited upon, and not just skipped over. + * This is a data integrity operation that waits upon dirty or in writeback + * pages. * * Return: %0 on success, negative error code otherwise. */ -int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, - loff_t end, int sync_mode) -{ - return filemap_writeback(mapping, start, end, sync_mode, NULL); -} - int filemap_fdatawrite_range(struct address_space *mapping, loff_t start, loff_t end) { - return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_ALL); + return filemap_writeback(mapping, start, end, WB_SYNC_ALL, NULL); } EXPORT_SYMBOL(filemap_fdatawrite_range); @@ -441,7 +432,7 @@ EXPORT_SYMBOL(filemap_fdatawrite); int filemap_fdatawrite_range_kick(struct address_space *mapping, loff_t start, loff_t end) { - return __filemap_fdatawrite_range(mapping, start, end, WB_SYNC_NONE); + return filemap_writeback(mapping, start, end, WB_SYNC_NONE, NULL); } EXPORT_SYMBOL_GPL(filemap_fdatawrite_range_kick); @@ -689,8 +680,7 @@ int filemap_write_and_wait_range(struct address_space *mapping, return 0; if (mapping_needs_writeback(mapping)) { - err = __filemap_fdatawrite_range(mapping, lstart, lend, - WB_SYNC_ALL); + err = filemap_fdatawrite_range(mapping, lstart, lend); /* * Even if the above returned error, the pages may be * written partially (e.g. -ENOSPC), so we wait for it. @@ -792,8 +782,7 @@ int file_write_and_wait_range(struct file *file, loff_t lstart, loff_t lend) return 0; if (mapping_needs_writeback(mapping)) { - err = __filemap_fdatawrite_range(mapping, lstart, lend, - WB_SYNC_ALL); + err = filemap_fdatawrite_range(mapping, lstart, lend); /* See comment of filemap_write_and_wait() */ if (err != -EIO) __filemap_fdatawait_range(mapping, lstart, lend); -- cgit v1.2.3 From c28d67b33cbf6da2043ee7517f1aa4cbf92dbbba Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Oct 2025 10:04:21 +0200 Subject: mm: rename filemap_fdatawrite_range_kick to filemap_flush_range Rename filemap_fdatawrite_range_kick to filemap_flush_range because it is the ranged version of filemap_flush. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251024080431.324236-11-hch@lst.de Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/sync.c | 3 +-- include/linux/fs.h | 6 +++--- mm/fadvise.c | 2 +- mm/filemap.c | 8 ++++---- 4 files changed, 9 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/fs/sync.c b/fs/sync.c index 6d8b04e04c3c..1759f6ba36cd 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -285,8 +285,7 @@ int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, ret = filemap_fdatawrite_range(mapping, offset, endbyte); else - ret = filemap_fdatawrite_range_kick(mapping, offset, - endbyte); + ret = filemap_flush_range(mapping, offset, endbyte); if (ret < 0) goto out; } diff --git a/include/linux/fs.h b/include/linux/fs.h index c895146c1444..a5dbfa20f8d7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3014,7 +3014,7 @@ extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart, extern int __must_check file_check_and_advance_wb_err(struct file *file); extern int __must_check file_write_and_wait_range(struct file *file, loff_t start, loff_t end); -int filemap_fdatawrite_range_kick(struct address_space *mapping, loff_t start, +int filemap_flush_range(struct address_space *mapping, loff_t start, loff_t end); static inline int file_write_and_wait(struct file *file) @@ -3051,8 +3051,8 @@ static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) } else if (iocb->ki_flags & IOCB_DONTCACHE) { struct address_space *mapping = iocb->ki_filp->f_mapping; - filemap_fdatawrite_range_kick(mapping, iocb->ki_pos - count, - iocb->ki_pos - 1); + filemap_flush_range(mapping, iocb->ki_pos - count, + iocb->ki_pos - 1); } return count; diff --git a/mm/fadvise.c b/mm/fadvise.c index f1be619f0e58..67028e30aa91 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -111,7 +111,7 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice) spin_unlock(&file->f_lock); break; case POSIX_FADV_DONTNEED: - filemap_fdatawrite_range_kick(mapping, offset, endbyte); + filemap_flush_range(mapping, offset, endbyte); /* * First and last FULL page! Partial pages are deliberately diff --git a/mm/filemap.c b/mm/filemap.c index f90f5bb2b825..fa770768ea3a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -419,7 +419,7 @@ int filemap_fdatawrite(struct address_space *mapping) EXPORT_SYMBOL(filemap_fdatawrite); /** - * filemap_fdatawrite_range_kick - start writeback on a range + * filemap_flush_range - start writeback on a range * @mapping: target address_space * @start: index to start writeback on * @end: last (inclusive) index for writeback @@ -429,12 +429,12 @@ EXPORT_SYMBOL(filemap_fdatawrite); * * Return: %0 on success, negative error code otherwise. */ -int filemap_fdatawrite_range_kick(struct address_space *mapping, loff_t start, +int filemap_flush_range(struct address_space *mapping, loff_t start, loff_t end) { return filemap_writeback(mapping, start, end, WB_SYNC_NONE, NULL); } -EXPORT_SYMBOL_GPL(filemap_fdatawrite_range_kick); +EXPORT_SYMBOL_GPL(filemap_flush_range); /** * filemap_flush - mostly a non-blocking flush @@ -447,7 +447,7 @@ EXPORT_SYMBOL_GPL(filemap_fdatawrite_range_kick); */ int filemap_flush(struct address_space *mapping) { - return filemap_fdatawrite_range_kick(mapping, 0, LLONG_MAX); + return filemap_flush_range(mapping, 0, LLONG_MAX); } EXPORT_SYMBOL(filemap_flush); -- cgit v1.2.3 From 90db4d4441f58d433ecf74f7e3bd17e0a553c20c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 17 Oct 2025 05:45:48 +0200 Subject: writeback: allow the file system to override MIN_WRITEBACK_PAGES The relatively low minimal writeback size of 4MiB means that written back inodes on rotational media are switched a lot. Besides introducing additional seeks, this also can lead to extreme file fragmentation on zoned devices when a lot of files are cached relative to the available writeback bandwidth. Add a superblock field that allows the file system to override the default size. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20251017034611.651385-3-hch@lst.de Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner --- fs/fs-writeback.c | 14 +++++--------- fs/super.c | 1 + include/linux/fs.h | 1 + include/linux/writeback.h | 5 +++++ 4 files changed, 12 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 30de37865fa1..52763fa499d6 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -32,11 +32,6 @@ #include #include "internal.h" -/* - * 4MB minimal write chunk size - */ -#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_SHIFT - 10)) - /* * Passed into wb_writeback(), essentially a subset of writeback_control */ @@ -1889,8 +1884,8 @@ out: return ret; } -static long writeback_chunk_size(struct bdi_writeback *wb, - struct wb_writeback_work *work) +static long writeback_chunk_size(struct super_block *sb, + struct bdi_writeback *wb, struct wb_writeback_work *work) { long pages; @@ -1913,7 +1908,8 @@ static long writeback_chunk_size(struct bdi_writeback *wb, pages = min(wb->avg_write_bandwidth / 2, global_wb_domain.dirty_limit / DIRTY_SCOPE); pages = min(pages, work->nr_pages); - return round_down(pages + MIN_WRITEBACK_PAGES, MIN_WRITEBACK_PAGES); + return round_down(pages + sb->s_min_writeback_pages, + sb->s_min_writeback_pages); } /* @@ -2015,7 +2011,7 @@ static long writeback_sb_inodes(struct super_block *sb, inode->i_state |= I_SYNC; wbc_attach_and_unlock_inode(&wbc, inode); - write_chunk = writeback_chunk_size(wb, work); + write_chunk = writeback_chunk_size(inode->i_sb, wb, work); wbc.nr_to_write = write_chunk; wbc.pages_skipped = 0; diff --git a/fs/super.c b/fs/super.c index 5bab94fb7e03..599c1d2641fe 100644 --- a/fs/super.c +++ b/fs/super.c @@ -389,6 +389,7 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, goto fail; if (list_lru_init_memcg(&s->s_inode_lru, s->s_shrink)) goto fail; + s->s_min_writeback_pages = MIN_WRITEBACK_PAGES; return s; fail: diff --git a/include/linux/fs.h b/include/linux/fs.h index a5dbfa20f8d7..6bf369095d2e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1583,6 +1583,7 @@ struct super_block { spinlock_t s_inode_wblist_lock; struct list_head s_inodes_wb; /* writeback inodes */ + long s_min_writeback_pages; } __randomize_layout; static inline struct user_namespace *i_user_ns(const struct inode *inode) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 22dd4adc5667..49e1dd96f43e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -374,4 +374,9 @@ bool redirty_page_for_writepage(struct writeback_control *, struct page *); void sb_mark_inode_writeback(struct inode *inode); void sb_clear_inode_writeback(struct inode *inode); +/* + * 4MB minimal write chunk size + */ +#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_SHIFT - 10)) + #endif /* WRITEBACK_H */ -- cgit v1.2.3 From 4952f35f0545f3b53dab8d5fd727c4827c2a2778 Mon Sep 17 00:00:00 2001 From: Julian Sun Date: Mon, 29 Sep 2025 19:13:49 +0800 Subject: fs: Make wbc_to_tag() inline and use it in fs. The logic in wbc_to_tag() is widely used in file systems, so modify this function to be inline and use it in file systems. This patch has only passed compilation tests, but it should be fine. Signed-off-by: Julian Sun Reviewed-by: Qu Wenruo Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/btrfs/extent_io.c | 5 +---- fs/ceph/addr.c | 6 +----- fs/ext4/inode.c | 5 +---- fs/f2fs/data.c | 5 +---- fs/gfs2/aops.c | 5 +---- include/linux/writeback.h | 7 +++++++ mm/page-writeback.c | 6 ------ 7 files changed, 12 insertions(+), 27 deletions(-) (limited to 'include/linux') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c123a3ef154a..170dd7e80d11 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2460,10 +2460,7 @@ static int extent_write_cache_pages(struct address_space *mapping, &BTRFS_I(inode)->runtime_flags)) wbc->tagged_writepages = 1; - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) tag_pages_for_writeback(mapping, index, end); diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 322ed268f14a..63b75d214210 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1045,11 +1045,7 @@ void ceph_init_writeback_ctl(struct address_space *mapping, ceph_wbc->index = ceph_wbc->start_index; ceph_wbc->end = -1; - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) { - ceph_wbc->tag = PAGECACHE_TAG_TOWRITE; - } else { - ceph_wbc->tag = PAGECACHE_TAG_DIRTY; - } + ceph_wbc->tag = wbc_to_tag(wbc); ceph_wbc->op_idx = -1; ceph_wbc->num_ops = 0; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f9e4ac87211e..58d6194045e2 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2619,10 +2619,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) handle_t *handle = NULL; int bpp = ext4_journal_blocks_per_folio(mpd->inode); - if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(mpd->wbc); mpd->map.m_len = 0; mpd->next_pos = mpd->start_pos; diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index ef38e62cda8f..826bcfb8230c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2986,10 +2986,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping, if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) range_whole = 1; } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: retry = 0; if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 47d74afd63ac..12394fc5dd29 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -311,10 +311,7 @@ static int gfs2_write_cache_jdata(struct address_space *mapping, range_whole = 1; cycled = 1; /* ignore range_cyclic tests */ } - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - tag = PAGECACHE_TAG_TOWRITE; - else - tag = PAGECACHE_TAG_DIRTY; + tag = wbc_to_tag(wbc); retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 49e1dd96f43e..2a81816f7507 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -196,6 +196,13 @@ static inline void wait_on_inode(struct inode *inode) !(READ_ONCE(inode->i_state) & I_NEW)); } +static inline xa_mark_t wbc_to_tag(struct writeback_control *wbc) +{ + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + return PAGECACHE_TAG_TOWRITE; + return PAGECACHE_TAG_DIRTY; +} + #ifdef CONFIG_CGROUP_WRITEBACK #include diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 757bc4d3b5b5..a124ab6a205d 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2434,12 +2434,6 @@ static bool folio_prepare_writeback(struct address_space *mapping, return true; } -static xa_mark_t wbc_to_tag(struct writeback_control *wbc) -{ - if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) - return PAGECACHE_TAG_TOWRITE; - return PAGECACHE_TAG_DIRTY; -} static pgoff_t wbc_end(struct writeback_control *wbc) { -- cgit v1.2.3