From: Omar Sandoval <[email protected]> As part of simplifying all of the private data passed around for direct I/O, bh->b_private will no longer be passed to dio_iodone_t. Instead, filesystems should use iocb->private. ocfs2 already uses iocb->private for storing a couple of flag bits, but we can use it as a tagged pointer and hide all of the messiness in helpers.
Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> --- fs/ocfs2/aops.c | 19 ++++++++------- fs/ocfs2/aops.h | 64 +++++++++++++++++++++++++++++++++---------------- 2 files changed, 54 insertions(+), 29 deletions(-) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 93ca23c56b07..fc4a18b6ad3c 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -2104,12 +2104,13 @@ struct ocfs2_dio_write_ctxt { }; static struct ocfs2_dio_write_ctxt * -ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc) +ocfs2_dio_alloc_write_ctx(struct kiocb *iocb, int *alloc) { - struct ocfs2_dio_write_ctxt *dwc = NULL; + struct ocfs2_dio_write_ctxt *dwc; - if (bh->b_private) - return bh->b_private; + dwc = ocfs2_iocb_private(iocb); + if (dwc) + return dwc; dwc = kmalloc(sizeof(struct ocfs2_dio_write_ctxt), GFP_NOFS); if (dwc == NULL) @@ -2118,7 +2119,7 @@ ocfs2_dio_alloc_write_ctx(struct buffer_head *bh, int *alloc) dwc->dw_zero_count = 0; dwc->dw_orphaned = 0; dwc->dw_writer_pid = task_pid_nr(current); - bh->b_private = dwc; + ocfs2_iocb_set_private(iocb, dwc); *alloc = 1; return dwc; @@ -2184,7 +2185,7 @@ static int ocfs2_dio_wr_get_block(struct kiocb *iocb, struct inode *inode, bh_result->b_state = 0; } - dwc = ocfs2_dio_alloc_write_ctx(bh_result, &first_get_block); + dwc = ocfs2_dio_alloc_write_ctx(iocb, &first_get_block); if (unlikely(dwc == NULL)) { ret = -ENOMEM; mlog_errno(ret); @@ -2408,6 +2409,7 @@ static int ocfs2_dio_end_io(struct kiocb *iocb, ssize_t bytes, void *private) { + struct ocfs2_dio_write_ctxt *dwc; struct inode *inode = file_inode(iocb->ki_filp); int level; int ret = 0; @@ -2415,8 +2417,9 @@ static int ocfs2_dio_end_io(struct kiocb *iocb, /* this io's submitter should not have unlocked this before we could */ BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); - if (bytes > 0 && private) - ret = ocfs2_dio_end_io_write(inode, private, offset, bytes); + dwc = ocfs2_iocb_private(iocb); + if (bytes > 0 && dwc) + ret = ocfs2_dio_end_io_write(inode, dwc, offset, bytes); ocfs2_iocb_clear_rw_locked(iocb); diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h index 3494a62ed749..2c3219e0c010 100644 --- a/fs/ocfs2/aops.h +++ b/fs/ocfs2/aops.h @@ -63,32 +63,54 @@ int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size); int ocfs2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); -/* all ocfs2_dio_end_io()'s fault */ -#define ocfs2_iocb_is_rw_locked(iocb) \ - test_bit(0, (unsigned long *)&iocb->private) + +/* + * Direct I/O uses iocb->private as a tagged pointer. The bottom two bits + * defined below are used for communication between ocfs2_dio_end_io() and + * ocfs2_file_write/read_iter(). + */ +#define OCFS2_IOCB_RW_LOCK 1 +#define OCFS2_IOCB_RW_LOCK_LEVEL 2 + +static inline void *ocfs2_iocb_private(struct kiocb *iocb) +{ + return (void *)((unsigned long)iocb->private & ~3); +} + +static inline void ocfs2_iocb_set_private(struct kiocb *iocb, void *private) +{ + iocb->private = (void *)(((unsigned long)iocb->private & 3) | + ((unsigned long)private & ~3)); +} + +static inline bool ocfs2_iocb_is_rw_locked(struct kiocb *iocb) +{ + return (unsigned long)iocb->private & OCFS2_IOCB_RW_LOCK; +} + static inline void ocfs2_iocb_set_rw_locked(struct kiocb *iocb, int level) { - set_bit(0, (unsigned long *)&iocb->private); + unsigned long private = (unsigned long)iocb->private; + + private |= OCFS2_IOCB_RW_LOCK; if (level) - set_bit(1, (unsigned long *)&iocb->private); + private |= OCFS2_IOCB_RW_LOCK_LEVEL; else - clear_bit(1, (unsigned long *)&iocb->private); + private &= ~OCFS2_IOCB_RW_LOCK_LEVEL; + iocb->private = (void *)private; } -/* - * Using a named enum representing lock types in terms of #N bit stored in - * iocb->private, which is going to be used for communication between - * ocfs2_dio_end_io() and ocfs2_file_write/read_iter(). - */ -enum ocfs2_iocb_lock_bits { - OCFS2_IOCB_RW_LOCK = 0, - OCFS2_IOCB_RW_LOCK_LEVEL, - OCFS2_IOCB_NUM_LOCKS -}; - -#define ocfs2_iocb_clear_rw_locked(iocb) \ - clear_bit(OCFS2_IOCB_RW_LOCK, (unsigned long *)&iocb->private) -#define ocfs2_iocb_rw_locked_level(iocb) \ - test_bit(OCFS2_IOCB_RW_LOCK_LEVEL, (unsigned long *)&iocb->private) +static inline void ocfs2_iocb_clear_rw_locked(struct kiocb *iocb) +{ + unsigned long private = (unsigned long)iocb->private; + + private &= ~OCFS2_IOCB_RW_LOCK; + iocb->private = (void *)private; +} + +static inline bool ocfs2_iocb_rw_locked_level(struct kiocb *iocb) +{ + return (unsigned long)iocb->private & OCFS2_IOCB_RW_LOCK_LEVEL; +} #endif /* OCFS2_FILE_H */ -- 2.18.0
