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| author | Christoph Hellwig <hch@infradead.org> | 2013-09-04 15:04:39 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-09-04 09:23:46 -0400 |
| commit | 7b7a8665edd8db733980389b098530f9e4f630b2 (patch) | |
| tree | 968d570a9f0c4d861226aefed2f5f97a131c8d53 /include | |
| parent | 4b6ccca701ef5977d0ffbc2c932430dea88b38b6 (diff) | |
| download | linux-stable-7b7a8665edd8db733980389b098530f9e4f630b2.tar.gz linux-stable-7b7a8665edd8db733980389b098530f9e4f630b2.tar.bz2 linux-stable-7b7a8665edd8db733980389b098530f9e4f630b2.zip | |
direct-io: Implement generic deferred AIO completions
Add support to the core direct-io code to defer AIO completions to user
context using a workqueue. This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.
The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.
Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara. I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.
JK: Fixed ext4 part, dynamic allocation of the workqueue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/buffer_head.h | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 7 |
2 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 91fa9a94ae92..d77797a52b7b 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -36,6 +36,7 @@ enum bh_state_bits { BH_Quiet, /* Buffer Error Prinks to be quiet */ BH_Meta, /* Buffer contains metadata */ BH_Prio, /* Buffer should be submitted with REQ_PRIO */ + BH_Defer_Completion, /* Defer AIO completion to workqueue */ BH_PrivateStart,/* not a state bit, but the first bit available * for private allocation by other entities @@ -128,6 +129,7 @@ BUFFER_FNS(Write_EIO, write_io_error) BUFFER_FNS(Unwritten, unwritten) BUFFER_FNS(Meta, meta) BUFFER_FNS(Prio, prio) +BUFFER_FNS(Defer_Completion, defer_completion) #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) diff --git a/include/linux/fs.h b/include/linux/fs.h index 65c9929cd340..c9013876eb29 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -46,6 +46,7 @@ struct vfsmount; struct cred; struct swap_info_struct; struct seq_file; +struct workqueue_struct; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -63,8 +64,7 @@ struct buffer_head; typedef int (get_block_t)(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, - ssize_t bytes, void *private, int ret, - bool is_async); + ssize_t bytes, void *private); #define MAY_EXEC 0x00000001 #define MAY_WRITE 0x00000002 @@ -1328,6 +1328,9 @@ struct super_block { /* Being remounted read-only */ int s_readonly_remount; + + /* AIO completions deferred from interrupt context */ + struct workqueue_struct *s_dio_done_wq; }; /* superblock cache pruning functions */ |