diff options
| author | Frank Mayhar <fmayhar@google.com> | 2010-05-17 08:00:00 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2010-05-17 08:00:00 -0400 |
| commit | 14ece1028b3ed53ffec1b1213ffc6acaf79ad77c (patch) | |
| tree | 8f5a13487139c68ef775c9d39b7be83386fdae06 | |
| parent | 60e6679e28518ccd67169c4a539d8cc7490eb8a6 (diff) | |
ext4: Make fsync sync new parent directories in no-journal mode
Add a new ext4 state to tell us when a file has been newly created; use
that state in ext4_sync_file in no-journal mode to tell us when we need
to sync the parent directory as well as the inode and data itself. This
fixes a problem in which a panic or power failure may lose the entire
file even when using fsync, since the parent directory entry is lost.
Addresses-Google-Bug: #2480057
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/ext4.h | 1 | ||||
| -rw-r--r-- | fs/ext4/fsync.c | 31 | ||||
| -rw-r--r-- | fs/ext4/namei.c | 2 |
3 files changed, 32 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 124ef771a618..60bd31026e7c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1180,6 +1180,7 @@ enum { EXT4_STATE_DA_ALLOC_CLOSE, /* Alloc DA blks on close */ EXT4_STATE_EXT_MIGRATE, /* Inode is migrating */ EXT4_STATE_DIO_UNWRITTEN, /* need convert on dio done*/ + EXT4_STATE_NEWENTRY, /* File just added to dir */ }; #define EXT4_INODE_BIT_FNS(name, field) \ diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c index 6ca7b6e59d83..e187f87acec0 100644 --- a/fs/ext4/fsync.c +++ b/fs/ext4/fsync.c @@ -35,6 +35,29 @@ #include <trace/events/ext4.h> /* + * If we're not journaling and this is a just-created file, we have to + * sync our parent directory (if it was freshly created) since + * otherwise it will only be written by writeback, leaving a huge + * window during which a crash may lose the file. This may apply for + * the parent directory's parent as well, and so on recursively, if + * they are also freshly created. + */ +static void ext4_sync_parent(struct inode *inode) +{ + struct dentry *dentry = NULL; + + while (inode && ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { + ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); + dentry = list_entry(inode->i_dentry.next, + struct dentry, d_alias); + if (!dentry || !dentry->d_parent || !dentry->d_parent->d_inode) + break; + inode = dentry->d_parent->d_inode; + sync_mapping_buffers(inode->i_mapping); + } +} + +/* * akpm: A new design for ext4_sync_file(). * * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). @@ -67,8 +90,12 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) if (ret < 0) return ret; - if (!journal) - return simple_fsync(file, dentry, datasync); + if (!journal) { + ret = simple_fsync(file, dentry, datasync); + if (!ret && !list_empty(&inode->i_dentry)) + ext4_sync_parent(inode); + return ret; + } /* * data=writeback,ordered: diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 83be743c8d1f..a43e6617b351 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1517,6 +1517,8 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry, de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize); retval = add_dirent_to_buf(handle, dentry, inode, de, bh); brelse(bh); + if (retval == 0) + ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); return retval; } |