From fe6c9c6e3e3e332b998393d214fba9d09ab0acb0 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 23 Jun 2022 10:51:46 -0700 Subject: mm: Add balance_dirty_pages_ratelimited_flags() function This adds the helper function balance_dirty_pages_ratelimited_flags(). It adds the parameter flags to balance_dirty_pages_ratelimited(). The flags parameter is passed to balance_dirty_pages(). For async buffered writes the flag value will be BDP_ASYNC. If balance_dirty_pages() gets called for async buffered write, we don't want to wait. Instead we need to indicate to the caller that throttling is needed so that it can stop writing and offload the rest of the write to a context that can block. The new helper function is also used by balance_dirty_pages_ratelimited(). Signed-off-by: Jan Kara Signed-off-by: Stefan Roesch Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220623175157.1715274-4-shr@fb.com [axboe: fix kerneltest bot 'ret' issue] Signed-off-by: Jens Axboe --- include/linux/writeback.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index da21d63f70e2..b8c9610c2313 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -364,7 +364,14 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); void wb_update_bandwidth(struct bdi_writeback *wb); + +/* Invoke balance dirty pages in async mode. */ +#define BDP_ASYNC 0x0001 + void balance_dirty_pages_ratelimited(struct address_space *mapping); +int balance_dirty_pages_ratelimited_flags(struct address_space *mapping, + unsigned int flags); + bool wb_over_bg_thresh(struct bdi_writeback *wb); typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, -- cgit v1.2.3-59-g8ed1b From 8017553980d0bbfef3e66c583363828565afd6da Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Thu, 23 Jun 2022 10:51:50 -0700 Subject: fs: add a FMODE_BUF_WASYNC flags for f_mode This introduces the flag FMODE_BUF_WASYNC. If devices support async buffered writes, this flag can be set. It also modifies the check in generic_write_checks to take async buffered writes into consideration. Signed-off-by: Stefan Roesch Reviewed-by: Christoph Hellwig Reviewed-by: Christian Brauner (Microsoft) Reviewed-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220623175157.1715274-8-shr@fb.com Signed-off-by: Jens Axboe --- fs/read_write.c | 4 +++- include/linux/fs.h | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/fs/read_write.c b/fs/read_write.c index e0777eefd846..319d88825d1c 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1660,7 +1660,9 @@ int generic_write_checks_count(struct kiocb *iocb, loff_t *count) if (iocb->ki_flags & IOCB_APPEND) iocb->ki_pos = i_size_read(inode); - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) + if ((iocb->ki_flags & IOCB_NOWAIT) && + !((iocb->ki_flags & IOCB_DIRECT) || + (file->f_mode & FMODE_BUF_WASYNC))) return -EINVAL; return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count); diff --git a/include/linux/fs.h b/include/linux/fs.h index 9ad5e3520fae..bc84847c201e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -180,6 +180,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* File supports async buffered reads */ #define FMODE_BUF_RASYNC ((__force fmode_t)0x40000000) +/* File supports async nowait buffered writes */ +#define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000) + /* * Attribute flags. These should be or-ed together to figure out what * has been changed! -- cgit v1.2.3-59-g8ed1b From 66fa3cedf16abc82d19b943e3289c82e685419d5 Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Thu, 23 Jun 2022 10:51:53 -0700 Subject: fs: Add async write file modification handling. This adds a file_modified_async() function to return -EAGAIN if the request either requires to remove privileges or needs to update the file modification time. This is required for async buffered writes, so the request gets handled in the io worker of io-uring. Signed-off-by: Stefan Roesch Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Christian Brauner (Microsoft) Reviewed-by: Darrick J. Wong Link: https://lore.kernel.org/r/20220623175157.1715274-11-shr@fb.com Signed-off-by: Jens Axboe --- fs/inode.c | 45 ++++++++++++++++++++++++++++++++++++++++++--- include/linux/fs.h | 1 + 2 files changed, 43 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/fs/inode.c b/fs/inode.c index ff726d99ecc7..259ebf438893 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2116,17 +2116,21 @@ int file_update_time(struct file *file) EXPORT_SYMBOL(file_update_time); /** - * file_modified - handle mandated vfs changes when modifying a file + * file_modified_flags - handle mandated vfs changes when modifying a file * @file: file that was modified + * @flags: kiocb flags * * When file has been modified ensure that special * file privileges are removed and time settings are updated. * + * If IOCB_NOWAIT is set, special file privileges will not be removed and + * time settings will not be updated. It will return -EAGAIN. + * * Context: Caller must hold the file's inode lock. * * Return: 0 on success, negative errno on failure. */ -int file_modified(struct file *file) +static int file_modified_flags(struct file *file, int flags) { int ret; struct inode *inode = file_inode(file); @@ -2136,7 +2140,7 @@ int file_modified(struct file *file) * Clear the security bits if the process is not being run by root. * This keeps people from modifying setuid and setgid binaries. */ - ret = __file_remove_privs(file, 0); + ret = __file_remove_privs(file, flags); if (ret) return ret; @@ -2146,11 +2150,46 @@ int file_modified(struct file *file) ret = inode_needs_update_time(inode, &now); if (ret <= 0) return ret; + if (flags & IOCB_NOWAIT) + return -EAGAIN; return __file_update_time(file, &now, ret); } + +/** + * file_modified - handle mandated vfs changes when modifying a file + * @file: file that was modified + * + * When file has been modified ensure that special + * file privileges are removed and time settings are updated. + * + * Context: Caller must hold the file's inode lock. + * + * Return: 0 on success, negative errno on failure. + */ +int file_modified(struct file *file) +{ + return file_modified_flags(file, 0); +} EXPORT_SYMBOL(file_modified); +/** + * kiocb_modified - handle mandated vfs changes when modifying a file + * @iocb: iocb that was modified + * + * When file has been modified ensure that special + * file privileges are removed and time settings are updated. + * + * Context: Caller must hold the file's inode lock. + * + * Return: 0 on success, negative errno on failure. + */ +int kiocb_modified(struct kiocb *iocb) +{ + return file_modified_flags(iocb->ki_filp, iocb->ki_flags); +} +EXPORT_SYMBOL_GPL(kiocb_modified); + int inode_needs_sync(struct inode *inode) { if (IS_SYNC(inode)) diff --git a/include/linux/fs.h b/include/linux/fs.h index bc84847c201e..c0d99b5a166b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2390,6 +2390,7 @@ static inline void file_accessed(struct file *file) } extern int file_modified(struct file *file); +int kiocb_modified(struct kiocb *iocb); int sync_inode_metadata(struct inode *inode, int wait); -- cgit v1.2.3-59-g8ed1b