diff options
Diffstat (limited to 'fs/ext3/fsync.c')
| -rw-r--r-- | fs/ext3/fsync.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c new file mode 100644 index 000000000..1cb9c7e10 --- /dev/null +++ b/fs/ext3/fsync.c @@ -0,0 +1,109 @@ +/* + * 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) { + /* Make sure that we read updated state */ + smp_rmb(); + if (EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS) + return -EROFS; + 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; +} |