From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by fg-out-1718.google.com with SMTP id e12so774850fga.4 for ; Thu, 10 Jan 2008 16:44:09 -0800 (PST) Subject: [PATCH 2/2][RFC][BUG] msync: updating ctime and mtime at syncing From: Anton Salikhmetov In-Reply-To: <1200006638.19293.42.camel@codedot> References: <1200006638.19293.42.camel@codedot> Content-Type: text/plain Date: Fri, 11 Jan 2008 03:44:09 +0300 Message-Id: <1200012249.20379.2.camel@codedot> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org From: Anton Salikhmetov Return-Path: To: linux-mm@kvack.org Cc: jakob@unthought.net, linux-kernel@vger.kernel.org, Valdis.Kletnieks@vt.edu, riel@redhat.com, ksm@42.dk, staubach@redhat.com, jesper.juhl@gmail.com List-ID: The patch contains changes for updating the ctime and mtime fields for memory mapped files: 1) adding a new flag triggering update of the inode data; 2) implementing a helper function for checking that flag and updating ctime and mtime; 3) updating time stamps for mapped files in sys_msync() and do_fsync(). Signed-off-by: Anton Salikhmetov --- diff --git a/fs/buffer.c b/fs/buffer.c index 7249e01..09adf7e 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -719,6 +719,7 @@ static int __set_page_dirty(struct page *page, } write_unlock_irq(&mapping->tree_lock); __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); + set_bit(AS_MCTIME, &mapping->flags); return 1; } diff --git a/fs/inode.c b/fs/inode.c index ed35383..c5b954e 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -22,6 +22,7 @@ #include #include #include +#include /* * This is needed for the following functions: @@ -1282,6 +1283,18 @@ void file_update_time(struct file *file) EXPORT_SYMBOL(file_update_time); +/* + * Update the ctime and mtime stamps after checking if they are to be updated. + */ +void mapped_file_update_time(struct file *file) +{ + if (test_and_clear_bit(AS_MCTIME, &file->f_mapping->flags)) { + get_file(file); + file_update_time(file); + fput(file); + } +} + int inode_needs_sync(struct inode *inode) { if (IS_SYNC(inode)) diff --git a/fs/sync.c b/fs/sync.c index 7cd005e..df57507 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -87,6 +87,8 @@ long do_fsync(struct file *file, int datasync) goto out; } + mapped_file_update_time(file); + ret = filemap_fdatawrite(mapping); /* diff --git a/include/linux/fs.h b/include/linux/fs.h index b3ec4a4..0b05118 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1978,6 +1978,7 @@ extern int inode_change_ok(struct inode *, struct iattr *); extern int __must_check inode_setattr(struct inode *, struct iattr *); extern void file_update_time(struct file *file); +extern void mapped_file_update_time(struct file *file); static inline ino_t parent_ino(struct dentry *dentry) { diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index db8a410..bf0f9e7 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -17,8 +17,9 @@ * Bits in mapping->flags. The lower __GFP_BITS_SHIFT bits are the page * allocation mode flags. */ -#define AS_EIO (__GFP_BITS_SHIFT + 0) /* IO error on async write */ +#define AS_EIO (__GFP_BITS_SHIFT + 0) /* IO error on async write */ #define AS_ENOSPC (__GFP_BITS_SHIFT + 1) /* ENOSPC on async write */ +#define AS_MCTIME (__GFP_BITS_SHIFT + 2) /* mtime and ctime to update */ static inline void mapping_set_error(struct address_space *mapping, int error) { diff --git a/mm/msync.c b/mm/msync.c index e788f7b..9d0a8f9 100644 --- a/mm/msync.c +++ b/mm/msync.c @@ -5,6 +5,7 @@ * Copyright (C) 1994-1999 Linus Torvalds * * Substantial code cleanup. + * Updating the ctime and mtime stamps for memory mapped files. * Copyright (C) 2008 Anton Salikhmetov */ @@ -22,6 +23,10 @@ * Nor does it mark the relevant pages dirty (it used to up to 2.6.17). * Now it doesn't do anything, since dirty pages are properly tracked. * + * The msync() system call updates the ctime and mtime fields for + * the mapped file when called with the MS_SYNC or MS_ASYNC flags + * according to the POSIX standard. + * * The application may now run fsync() to * write out the dirty pages and wait on the writeout and check the result. * Or the application may run fadvise(FADV_DONTNEED) against the fd to start @@ -74,14 +79,17 @@ asmlinkage long sys_msync(unsigned long start, size_t len, int flags) break; } file = vma->vm_file; - if ((flags & MS_SYNC) && file && (vma->vm_flags & VM_SHARED)) { - get_file(file); - up_read(&mm->mmap_sem); - error = do_fsync(file, 0); - fput(file); - if (error) - return error; - down_read(&mm->mmap_sem); + if (file && (vma->vm_flags & VM_SHARED)) { + mapped_file_update_time(file); + if (flags & MS_SYNC) { + get_file(file); + up_read(&mm->mmap_sem); + error = do_fsync(file, 0); + fput(file); + if (error) + return error; + down_read(&mm->mmap_sem); + } } start = vma->vm_end; diff --git a/mm/page-writeback.c b/mm/page-writeback.c index d55cfca..a85df0b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1025,6 +1025,7 @@ int __set_page_dirty_nobuffers(struct page *page) if (mapping->host) { /* !PageAnon && !swapper_space */ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); + set_bit(AS_MCTIME, &mapping->flags); } return 1; } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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