lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20240130055414.2143959-2-willy@infradead.org> Date: Tue, 30 Jan 2024 05:54:11 +0000 From: "Matthew Wilcox (Oracle)" <willy@...radead.org> To: Christoph Hellwig <hch@....de> Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>, linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org Subject: [PATCH 1/3] fs: Introduce buffered_write_operations Start the process of moving write_begin and write_end out from the address_space_operations to their own struct. Make them take a folio instead of a page, and pass a pointer to the fsdata to write_end (so that we don't need to initialise it). Pass an optional buffered_write_operations pointer to various functions in filemap.c. The old names are available as macros for now, except for generic_file_write_iter() which is used as a function pointer by many filesystems. Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org> --- fs/jfs/file.c | 3 +- fs/ramfs/file-mmu.c | 3 +- fs/ufs/file.c | 2 +- include/linux/fs.h | 3 -- include/linux/pagemap.h | 22 +++++++++++++ mm/filemap.c | 70 +++++++++++++++++++++++++++-------------- 6 files changed, 71 insertions(+), 32 deletions(-) diff --git a/fs/jfs/file.c b/fs/jfs/file.c index 01b6912e60f8..9c62445ea6be 100644 --- a/fs/jfs/file.c +++ b/fs/jfs/file.c @@ -4,8 +4,7 @@ * Portions Copyright (C) Christoph Hellwig, 2001-2002 */ -#include <linux/mm.h> -#include <linux/fs.h> +#include <linux/pagemap.h> #include <linux/posix_acl.h> #include <linux/quotaops.h> #include "jfs_incore.h" diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c index c7a1aa3c882b..a621b08b0235 100644 --- a/fs/ramfs/file-mmu.c +++ b/fs/ramfs/file-mmu.c @@ -24,8 +24,7 @@ * caches is sufficient. */ -#include <linux/fs.h> -#include <linux/mm.h> +#include <linux/pagemap.h> #include <linux/ramfs.h> #include <linux/sched.h> diff --git a/fs/ufs/file.c b/fs/ufs/file.c index 6558882a89ef..b557d4a14143 100644 --- a/fs/ufs/file.c +++ b/fs/ufs/file.c @@ -24,7 +24,7 @@ * ext2 fs regular file handling primitives */ -#include <linux/fs.h> +#include <linux/pagemap.h> #include "ufs_fs.h" #include "ufs.h" diff --git a/include/linux/fs.h b/include/linux/fs.h index ed5966a70495..92dc0cf08b1f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3048,10 +3048,7 @@ extern int generic_file_rw_checks(struct file *file_in, struct file *file_out); ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to, ssize_t already_read); extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); -extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); -extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *); -ssize_t generic_perform_write(struct kiocb *, struct iov_iter *); ssize_t direct_write_fallback(struct kiocb *iocb, struct iov_iter *iter, ssize_t direct_written, ssize_t buffered_written); diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 2df35e65557d..a5c474ad230e 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -18,6 +18,28 @@ struct folio_batch; +struct buffered_write_operations { + int (*write_begin)(struct file *, struct address_space *mapping, + loff_t pos, size_t len, struct folio **foliop, + void **fsdata); + int (*write_end)(struct file *, struct address_space *mapping, + loff_t pos, size_t len, size_t copied, + struct folio *folio, void **fsdata); +}; + +ssize_t filemap_write_iter(struct kiocb *, struct iov_iter *, + const struct buffered_write_operations *); +ssize_t __filemap_write_iter(struct kiocb *, struct iov_iter *, + const struct buffered_write_operations *); +ssize_t filemap_perform_write(struct kiocb *, struct iov_iter *, + const struct buffered_write_operations *); + +ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); +#define generic_perform_write(kiocb, iter) \ + filemap_perform_write(kiocb, iter, NULL) +#define __generic_file_write_iter(kiocb, iter) \ + __filemap_write_iter(kiocb, iter, NULL) + unsigned long invalidate_mapping_pages(struct address_space *mapping, pgoff_t start, pgoff_t end); diff --git a/mm/filemap.c b/mm/filemap.c index 750e779c23db..66d779b787c8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -95,7 +95,7 @@ * ->invalidate_lock (filemap_fault) * ->lock_page (filemap_fault, access_process_vm) * - * ->i_rwsem (generic_perform_write) + * ->i_rwsem (filemap_perform_write) * ->mmap_lock (fault_in_readable->do_page_fault) * * bdi->wb.list_lock @@ -3890,7 +3890,8 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from) } EXPORT_SYMBOL(generic_file_direct_write); -ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) +ssize_t filemap_perform_write(struct kiocb *iocb, struct iov_iter *i, + const struct buffered_write_operations *ops) { struct file *file = iocb->ki_filp; loff_t pos = iocb->ki_pos; @@ -3900,9 +3901,9 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) ssize_t written = 0; do { - struct page *page; - unsigned long offset; /* Offset into pagecache page */ - unsigned long bytes; /* Bytes to write to page */ + struct folio *folio; + size_t offset; /* Offset into pagecache folio */ + size_t bytes; /* Bytes to write to page */ size_t copied; /* Bytes copied from user */ void *fsdata = NULL; @@ -3927,19 +3928,31 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) break; } - status = a_ops->write_begin(file, mapping, pos, bytes, + if (ops) + status = ops->write_begin(file, mapping, pos, bytes, + &folio, &fsdata); + else { + struct page *page; + status = a_ops->write_begin(file, mapping, pos, bytes, &page, &fsdata); + if (status >= 0) + folio = page_folio(page); + } if (unlikely(status < 0)) break; if (mapping_writably_mapped(mapping)) - flush_dcache_page(page); + flush_dcache_folio(folio); - copied = copy_page_from_iter_atomic(page, offset, bytes, i); - flush_dcache_page(page); + copied = copy_folio_from_iter_atomic(folio, offset, bytes, i); + flush_dcache_folio(folio); - status = a_ops->write_end(file, mapping, pos, bytes, copied, - page, fsdata); + if (ops) + status = ops->write_end(file, mapping, pos, bytes, + copied, folio, &fsdata); + else + status = a_ops->write_end(file, mapping, pos, bytes, + copied, &folio->page, fsdata); if (unlikely(status != copied)) { iov_iter_revert(i, copied - max(status, 0L)); if (unlikely(status < 0)) @@ -3969,12 +3982,13 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i) iocb->ki_pos += written; return written; } -EXPORT_SYMBOL(generic_perform_write); +EXPORT_SYMBOL(filemap_perform_write); /** - * __generic_file_write_iter - write data to a file - * @iocb: IO state structure (file, offset, etc.) - * @from: iov_iter with data to write + * __filemap_write_iter - write data to a file + * @iocb: IO state structure (file, offset, etc.) + * @from: iov_iter with data to write + * @ops: How to inform the filesystem that a write is starting/finishing. * * This function does all the work needed for actually writing data to a * file. It does all basic checks, removes SUID from the file, updates @@ -3992,7 +4006,8 @@ EXPORT_SYMBOL(generic_perform_write); * * number of bytes written, even for truncated writes * * negative error code if no data has been written at all */ -ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +ssize_t __filemap_write_iter(struct kiocb *iocb, struct iov_iter *from, + const struct buffered_write_operations *ops) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -4019,27 +4034,29 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (ret < 0 || !iov_iter_count(from) || IS_DAX(inode)) return ret; return direct_write_fallback(iocb, from, ret, - generic_perform_write(iocb, from)); + filemap_perform_write(iocb, from, ops)); } - return generic_perform_write(iocb, from); + return filemap_perform_write(iocb, from, ops); } -EXPORT_SYMBOL(__generic_file_write_iter); +EXPORT_SYMBOL(__filemap_write_iter); /** - * generic_file_write_iter - write data to a file + * filemap_write_iter - write data to a file * @iocb: IO state structure * @from: iov_iter with data to write * - * This is a wrapper around __generic_file_write_iter() to be used by most + * This is a wrapper around __filemap_write_iter() to be used by most * filesystems. It takes care of syncing the file in case of O_SYNC file * and acquires i_rwsem as needed. + * * Return: - * * negative error code if no data has been written at all of + * * negative error code if no data has been written at all or if * vfs_fsync_range() failed for a synchronous write * * number of bytes written, even for truncated writes */ -ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +ssize_t filemap_write_iter(struct kiocb *iocb, struct iov_iter *from, + const struct buffered_write_operations *ops) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; @@ -4048,13 +4065,18 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) inode_lock(inode); ret = generic_write_checks(iocb, from); if (ret > 0) - ret = __generic_file_write_iter(iocb, from); + ret = __filemap_write_iter(iocb, from, ops); inode_unlock(inode); if (ret > 0) ret = generic_write_sync(iocb, ret); return ret; } + +ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + return filemap_write_iter(iocb, from, NULL); +} EXPORT_SYMBOL(generic_file_write_iter); /** -- 2.43.0
Powered by blists - more mailing lists