diff options
Diffstat (limited to 'fs/ext4/file.c')
-rw-r--r-- | fs/ext4/file.c | 155 |
1 files changed, 78 insertions, 77 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index ca7502d89fd..4e8bc284ec0 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -57,7 +57,7 @@ static int ext4_release_file(struct inode *inode, struct file *filp) return 0; } -void ext4_unwritten_wait(struct inode *inode) +static void ext4_unwritten_wait(struct inode *inode) { wait_queue_head_t *wq = ext4_ioend_wq(inode); @@ -82,7 +82,7 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov, size_t count = iov_length(iov, nr_segs); loff_t final_size = pos + count; - if (pos >= inode->i_size) + if (pos >= i_size_read(inode)) return 0; if ((pos & blockmask) || (final_size & blockmask)) @@ -92,58 +92,91 @@ 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) +ext4_file_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 inode *inode = file_inode(iocb->ki_filp); + struct mutex *aio_mutex = NULL; struct blk_plug plug; - int unaligned_aio = 0; - ssize_t ret; + int o_direct = file->f_flags & O_DIRECT; int overwrite = 0; size_t length = iov_length(iov, nr_segs); + ssize_t ret; - if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && - !is_sync_kiocb(iocb)) - unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos); + BUG_ON(iocb->ki_pos != pos); - /* Unaligned direct AIO must be serialized; see comment above */ - if (unaligned_aio) { - mutex_lock(ext4_aio_mutex(inode)); + /* + * Unaligned direct AIO must be serialized; see comment above + * In the case of O_APPEND, assume that we must always serialize + */ + if (o_direct && + ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && + !is_sync_kiocb(iocb) && + (file->f_flags & O_APPEND || + ext4_unaligned_aio(inode, iov, nr_segs, pos))) { + aio_mutex = ext4_aio_mutex(inode); + mutex_lock(aio_mutex); ext4_unwritten_wait(inode); } - BUG_ON(iocb->ki_pos != pos); - mutex_lock(&inode->i_mutex); - blk_start_plug(&plug); + if (file->f_flags & O_APPEND) + iocb->ki_pos = pos = i_size_read(inode); + + /* + * If we have encountered a bitmap-format file, the size limit + * is smaller than s_maxbytes, which is for extent-mapped files. + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); - iocb->private = &overwrite; + if ((pos > sbi->s_bitmap_maxbytes) || + (pos == sbi->s_bitmap_maxbytes && length > 0)) { + mutex_unlock(&inode->i_mutex); + ret = -EFBIG; + goto errout; + } - /* 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; + if (pos + length > sbi->s_bitmap_maxbytes) { + nr_segs = iov_shorten((struct iovec *)iov, nr_segs, + sbi->s_bitmap_maxbytes - pos); + } + } - map.m_lblk = pos >> blkbits; - map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits) - - map.m_lblk; - len = map.m_len; + if (o_direct) { + blk_start_plug(&plug); - 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; + iocb->private = &overwrite; + + /* check whether we do a DIO overwrite or not */ + if (ext4_should_dioread_nolock(inode) && !aio_mutex && + !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 + * unwritten 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); @@ -156,45 +189,12 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov, if (err < 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 = file_inode(iocb->ki_filp); - ssize_t ret; - - /* - * If we have encountered a bitmap-format file, the size limit - * is smaller than s_maxbytes, which is for extent-mapped files. - */ - - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { - struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); - size_t length = iov_length(iov, nr_segs); - - if ((pos > sbi->s_bitmap_maxbytes || - (pos == sbi->s_bitmap_maxbytes && length > 0))) - return -EFBIG; - - if (pos + length > sbi->s_bitmap_maxbytes) { - nr_segs = iov_shorten((struct iovec *)iov, nr_segs, - sbi->s_bitmap_maxbytes - pos); - } - } - - 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); + if (o_direct) + blk_finish_plug(&plug); +errout: + if (aio_mutex) + mutex_unlock(aio_mutex); return ret; } @@ -244,6 +244,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); if (IS_ERR(handle)) return PTR_ERR(handle); + BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) { ext4_journal_stop(handle); |