diff options
Diffstat (limited to 'fs/ext4/fsync.c')
| -rw-r--r-- | fs/ext4/fsync.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c new file mode 100644 index 0000000..dd1fd3c --- /dev/null +++ b/fs/ext4/fsync.c @@ -0,0 +1,88 @@ +/* + * linux/fs/ext3/fsync.c + * + * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) + * from + * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * from + * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds + * + * ext3fs fsync primitive + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + * + * Removed unnecessary code duplication for little endian machines + * and excessive __inline__s. + * Andi Kleen, 1997 + * + * Major simplications and cleanup - we only need to do the metadata, because + * we can depend on generic_block_fdatasync() to sync the data blocks. + */ + +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include <linux/writeback.h> +#include <linux/jbd.h> +#include <linux/ext3_fs.h> +#include <linux/ext3_jbd.h> + +/* + * akpm: A new design for ext3_sync_file(). + * + * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). + * There cannot be a transaction open by this task. + * Another task could have dirtied this inode. Its data can be in any + * state in the journalling system. + * + * What we do is just kick off a commit and wait on it. This will snapshot the + * inode to disk. + */ + +int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync) +{ + struct inode *inode = dentry->d_inode; + int ret = 0; + + J_ASSERT(ext3_journal_current_handle() == 0); + + /* + * data=writeback: + * The caller's filemap_fdatawrite()/wait will sync the data. + * sync_inode() will sync the metadata + * + * data=ordered: + * The caller's filemap_fdatawrite() will write the data and + * sync_inode() will write the inode if it is dirty. Then the caller's + * filemap_fdatawait() will wait on the pages. + * + * data=journal: + * filemap_fdatawrite won't do anything (the buffers are clean). + * ext3_force_commit will write the file data into the journal and + * will wait on that. + * filemap_fdatawait() will encounter a ton of newly-dirtied pages + * (they were dirtied by commit). But that's OK - the blocks are + * safe in-journal, which is all fsync() needs to ensure. + */ + if (ext3_should_journal_data(inode)) { + ret = ext3_force_commit(inode->i_sb); + goto out; + } + + /* + * The VFS has written the file data. If the inode is unaltered + * then we need not start a commit. + */ + if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = 0, /* sys_fsync did this */ + }; + ret = sync_inode(inode, &wbc); + } +out: + return ret; +} |