diff options
| -rw-r--r-- | fs/ext4/ext4.h | 10 | ||||
| -rw-r--r-- | fs/ext4/extents.c | 10 | ||||
| -rw-r--r-- | fs/ext4/file.c | 60 | ||||
| -rw-r--r-- | fs/ext4/page-io.c | 25 | ||||
| -rw-r--r-- | fs/ext4/super.c | 13 |
5 files changed, 100 insertions, 18 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 0c8d97b..3aa0b72 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -848,6 +848,7 @@ struct ext4_inode_info { atomic_t i_ioend_count; /* Number of outstanding io_end structs */ /* current io_end structure for async DIO write*/ ext4_io_end_t *cur_aio_dio; + atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */ spinlock_t i_block_reservation_lock; @@ -2119,6 +2120,15 @@ static inline void set_bitmap_uptodate(struct buffer_head *bh) #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) +/* For ioend & aio unwritten conversion wait queues */ +#define EXT4_WQ_HASH_SZ 37 +#define ext4_ioend_wq(v) (&ext4__ioend_wq[((unsigned long)(v)) %\ + EXT4_WQ_HASH_SZ]) +#define ext4_aio_mutex(v) (&ext4__aio_mutex[((unsigned long)(v)) %\ + EXT4_WQ_HASH_SZ]) +extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ]; +extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ]; + #endif /* __KERNEL__ */ #endif /* _EXT4_H */ diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 63a7581..ccce8a7 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3174,9 +3174,10 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, * that this IO needs to convertion to written when IO is * completed */ - if (io) + if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { io->flag = EXT4_IO_END_UNWRITTEN; - else + atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); + } else ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); if (ext4_should_dioread_nolock(inode)) map->m_flags |= EXT4_MAP_UNINIT; @@ -3463,9 +3464,10 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, * that we need to perform convertion when IO is done. */ if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { - if (io) + if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { io->flag = EXT4_IO_END_UNWRITTEN; - else + atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); + } else ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); } diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 2e8322c..7b80d54 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -55,11 +55,47 @@ static int ext4_release_file(struct inode *inode, struct file *filp) return 0; } +static void ext4_aiodio_wait(struct inode *inode) +{ + wait_queue_head_t *wq = ext4_ioend_wq(inode); + + wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_aiodio_unwritten) == 0)); +} + +/* + * This tests whether the IO in question is block-aligned or not. + * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they + * are converted to written only after the IO is complete. Until they are + * mapped, these blocks appear as holes, so dio_zero_block() will assume that + * it needs to zero out portions of the start and/or end block. If 2 AIO + * threads are at work on the same unwritten block, they must be synchronized + * or one thread will zero the other's data, causing corruption. + */ +static int +ext4_unaligned_aio(struct inode *inode, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct super_block *sb = inode->i_sb; + int blockmask = sb->s_blocksize - 1; + size_t count = iov_length(iov, nr_segs); + loff_t final_size = pos + count; + + if (pos >= inode->i_size) + return 0; + + if ((pos & blockmask) || (final_size & blockmask)) + return 1; + + return 0; +} + 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; + int ret; /* * If we have encountered a bitmap-format file, the size limit @@ -78,9 +114,31 @@ 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); } - return generic_file_aio_write(iocb, 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)); + + return ret; } static const struct vm_operations_struct ext4_file_vm_ops = { diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 4e9b0a2..955cc30 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -32,14 +32,8 @@ static struct kmem_cache *io_page_cachep, *io_end_cachep; -#define WQ_HASH_SZ 37 -#define to_ioend_wq(v) (&ioend_wq[((unsigned long)v) % WQ_HASH_SZ]) -static wait_queue_head_t ioend_wq[WQ_HASH_SZ]; - int __init ext4_init_pageio(void) { - int i; - io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT); if (io_page_cachep == NULL) return -ENOMEM; @@ -48,9 +42,6 @@ int __init ext4_init_pageio(void) kmem_cache_destroy(io_page_cachep); return -ENOMEM; } - for (i = 0; i < WQ_HASH_SZ; i++) - init_waitqueue_head(&ioend_wq[i]); - return 0; } @@ -62,7 +53,7 @@ void ext4_exit_pageio(void) void ext4_ioend_wait(struct inode *inode) { - wait_queue_head_t *wq = to_ioend_wq(inode); + wait_queue_head_t *wq = ext4_ioend_wq(inode); wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0)); } @@ -87,7 +78,7 @@ void ext4_free_io_end(ext4_io_end_t *io) for (i = 0; i < io->num_io_pages; i++) put_io_page(io->pages[i]); io->num_io_pages = 0; - wq = to_ioend_wq(io->inode); + wq = ext4_ioend_wq(io->inode); if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count) && waitqueue_active(wq)) wake_up_all(wq); @@ -102,6 +93,7 @@ int ext4_end_io_nolock(ext4_io_end_t *io) struct inode *inode = io->inode; loff_t offset = io->offset; ssize_t size = io->size; + wait_queue_head_t *wq; int ret = 0; ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," @@ -126,7 +118,16 @@ int ext4_end_io_nolock(ext4_io_end_t *io) if (io->iocb) aio_complete(io->iocb, io->result, 0); /* clear the DIO AIO unwritten flag */ - io->flag &= ~EXT4_IO_END_UNWRITTEN; + if (io->flag & EXT4_IO_END_UNWRITTEN) { + io->flag &= ~EXT4_IO_END_UNWRITTEN; + /* Wake up anyone waiting on unwritten extent conversion */ + wq = ext4_ioend_wq(io->inode); + if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten) && + waitqueue_active(wq)) { + wake_up_all(wq); + } + } + return ret; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 86b0548..f6a318f 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -833,6 +833,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) ei->i_sync_tid = 0; ei->i_datasync_tid = 0; atomic_set(&ei->i_ioend_count, 0); + atomic_set(&ei->i_aiodio_unwritten, 0); return &ei->vfs_inode; } @@ -4800,11 +4801,21 @@ static void ext4_exit_feat_adverts(void) kfree(ext4_feat); } +/* Shared across all ext4 file systems */ +wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ]; +struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ]; + static int __init ext4_init_fs(void) { - int err; + int i, err; ext4_check_flag_values(); + + for (i = 0; i < EXT4_WQ_HASH_SZ; i++) { + mutex_init(&ext4__aio_mutex[i]); + init_waitqueue_head(&ext4__ioend_wq[i]); + } + err = ext4_init_pageio(); if (err) return err; |