diff options
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 121 |
1 files changed, 98 insertions, 23 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 782eecb..3b0e3bd 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -90,11 +90,91 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov, } static ssize_t +ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + struct blk_plug plug; + int unaligned_aio = 0; + ssize_t ret; + int overwrite = 0; + size_t length = iov_length(iov, nr_segs); + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && + !is_sync_kiocb(iocb)) + unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos); + + /* Unaligned direct AIO must be serialized; see comment above */ + if (unaligned_aio) { + static unsigned long unaligned_warn_time; + + /* Warn about this once per day */ + if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ)) + ext4_msg(inode->i_sb, KERN_WARNING, + "Unaligned AIO/DIO on inode %ld by %s; " + "performance will be poor.", + inode->i_ino, current->comm); + mutex_lock(ext4_aio_mutex(inode)); + ext4_aiodio_wait(inode); + } + + BUG_ON(iocb->ki_pos != pos); + + mutex_lock(&inode->i_mutex); + blk_start_plug(&plug); + + iocb->private = &overwrite; + + /* check whether we do a DIO overwrite or not */ + if (ext4_should_dioread_nolock(inode) && !unaligned_aio && + !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) { + struct ext4_map_blocks map; + unsigned int blkbits = inode->i_blkbits; + int err, len; + + map.m_lblk = pos >> blkbits; + map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits) + - map.m_lblk; + len = map.m_len; + + err = ext4_map_blocks(NULL, inode, &map, 0); + /* + * 'err==len' means that all of blocks has been preallocated no + * matter they are initialized or not. For excluding + * uninitialized extents, we need to check m_flags. There are + * two conditions that indicate for initialized extents. + * 1) If we hit extent cache, EXT4_MAP_MAPPED flag is returned; + * 2) If we do a real lookup, non-flags are returned. + * So we should check these two conditions. + */ + if (err == len && (map.m_flags & EXT4_MAP_MAPPED)) + overwrite = 1; + } + + ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); + mutex_unlock(&inode->i_mutex); + + if (ret > 0 || ret == -EIOCBQUEUED) { + ssize_t err; + + err = generic_write_sync(file, pos, ret); + if (err < 0 && ret > 0) + ret = err; + } + blk_finish_plug(&plug); + + if (unaligned_aio) + mutex_unlock(ext4_aio_mutex(inode)); + + return ret; +} + +static ssize_t ext4_file_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) { struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; - int unaligned_aio = 0; ssize_t ret; /* @@ -114,29 +194,12 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov, nr_segs = iov_shorten((struct iovec *)iov, nr_segs, sbi->s_bitmap_maxbytes - pos); } - } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) && - !is_sync_kiocb(iocb))) { - unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos); } - /* Unaligned direct AIO must be serialized; see comment above */ - if (unaligned_aio) { - static unsigned long unaligned_warn_time; - - /* Warn about this once per day */ - if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ)) - ext4_msg(inode->i_sb, KERN_WARNING, - "Unaligned AIO/DIO on inode %ld by %s; " - "performance will be poor.", - inode->i_ino, current->comm); - mutex_lock(ext4_aio_mutex(inode)); - ext4_aiodio_wait(inode); - } - - ret = generic_file_aio_write(iocb, iov, nr_segs, pos); - - if (unaligned_aio) - mutex_unlock(ext4_aio_mutex(inode)); + if (unlikely(iocb->ki_filp->f_flags & O_DIRECT)) + ret = ext4_file_dio_write(iocb, iov, nr_segs, pos); + else + ret = generic_file_aio_write(iocb, iov, nr_segs, pos); return ret; } @@ -181,9 +244,21 @@ static int ext4_file_open(struct inode * inode, struct file * filp) path.dentry = mnt->mnt_root; cp = d_path(&path, buf, sizeof(buf)); if (!IS_ERR(cp)) { + handle_t *handle; + int err; + + handle = ext4_journal_start_sb(sb, 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + err = ext4_journal_get_write_access(handle, sbi->s_sbh); + if (err) { + ext4_journal_stop(handle); + return err; + } strlcpy(sbi->s_es->s_last_mounted, cp, sizeof(sbi->s_es->s_last_mounted)); - ext4_mark_super_dirty(sb); + ext4_handle_dirty_super(handle, sb); + ext4_journal_stop(handle); } } /* |