| /* |
| * 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/blkdev.h> |
| #include <linux/writeback.h> |
| #include "ext3.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, loff_t start, loff_t end, int datasync) |
| { |
| struct inode *inode = file->f_mapping->host; |
| struct ext3_inode_info *ei = EXT3_I(inode); |
| journal_t *journal = EXT3_SB(inode->i_sb)->s_journal; |
| int ret, needs_barrier = 0; |
| tid_t commit_tid; |
| |
| trace_ext3_sync_file_enter(file, datasync); |
| |
| if (inode->i_sb->s_flags & MS_RDONLY) |
| return 0; |
| |
| ret = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| if (ret) |
| goto out; |
| |
| J_ASSERT(ext3_journal_current_handle() == NULL); |
| |
| /* |
| * data=writeback,ordered: |
| * The caller's filemap_fdatawrite()/wait will sync the data. |
| * Metadata is in the journal, we wait for a proper transaction |
| * to commit here. |
| * |
| * 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; |
| } |
| |
| if (datasync) |
| commit_tid = atomic_read(&ei->i_datasync_tid); |
| else |
| commit_tid = atomic_read(&ei->i_sync_tid); |
| |
| if (test_opt(inode->i_sb, BARRIER) && |
| !journal_trans_will_send_data_barrier(journal, commit_tid)) |
| needs_barrier = 1; |
| log_start_commit(journal, commit_tid); |
| ret = log_wait_commit(journal, commit_tid); |
| |
| /* |
| * In case we didn't commit a transaction, we have to flush |
| * disk caches manually so that data really is on persistent |
| * storage |
| */ |
| if (needs_barrier) { |
| int err; |
| |
| err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); |
| if (!ret) |
| ret = err; |
| } |
| out: |
| trace_ext3_sync_file_exit(inode, ret); |
| return ret; |
| } |