diff options
| -rw-r--r-- | Documentation/filesystems/iomap/operations.rst | 20 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 2 | ||||
| -rw-r--r-- | fs/iomap/direct-io.c | 20 | ||||
| -rw-r--r-- | fs/iomap/trace.h | 2 | ||||
| -rw-r--r-- | include/linux/iomap.h | 8 |
5 files changed, 36 insertions, 16 deletions
diff --git a/Documentation/filesystems/iomap/operations.rst b/Documentation/filesystems/iomap/operations.rst index d1535109587a..b08a79d11d9f 100644 --- a/Documentation/filesystems/iomap/operations.rst +++ b/Documentation/filesystems/iomap/operations.rst @@ -514,8 +514,8 @@ IOMAP_WRITE`` with any combination of the following enhancements: if the mapping is unwritten and the filesystem cannot handle zeroing the unaligned regions without exposing stale contents. - * ``IOMAP_ATOMIC``: This write is being issued with torn-write - protection. + * ``IOMAP_ATOMIC_HW``: This write is being issued with torn-write + protection based on HW-offload support. Only a single bio can be created for the write, and the write must not be split into multiple I/O requests, i.e. flag REQ_ATOMIC must be set. @@ -526,8 +526,20 @@ IOMAP_WRITE`` with any combination of the following enhancements: conversion or copy on write), all updates for the entire file range must be committed atomically as well. Only one space mapping is allowed per untorn write. - Untorn writes must be aligned to, and must not be longer than, a - single file block. + Untorn writes may be longer than a single file block. In all cases, + the mapping start disk block must have at least the same alignment as + the write offset. + + * ``IOMAP_ATOMIC_SW``: This write is being issued with torn-write + protection via a software mechanism provided by the filesystem. + All the disk block alignment and single bio restrictions which apply + to IOMAP_ATOMIC_HW do not apply here. + SW-based untorn writes would typically be used as a fallback when + HW-based untorn writes may not be issued, e.g. the range of the write + covers multiple extents, meaning that it is not possible to issue + a single bio. + All filesystem metadata updates for the entire file range must be + committed atomically as well. Callers commonly hold ``i_rwsem`` in shared or exclusive mode before calling this function. diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 7c54ae5fcbd4..ba2f1e3db7c7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3467,7 +3467,7 @@ static inline bool ext4_want_directio_fallback(unsigned flags, ssize_t written) return false; /* atomic writes are all-or-nothing */ - if (flags & IOMAP_ATOMIC) + if (flags & IOMAP_ATOMIC_HW) return false; /* can only try again if we wrote nothing */ diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index e1e32e2bb0bf..5299f70428ef 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -317,7 +317,7 @@ static int iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, * clearing the WRITE_THROUGH flag in the dio request. */ static inline blk_opf_t iomap_dio_bio_opflags(struct iomap_dio *dio, - const struct iomap *iomap, bool use_fua, bool atomic) + const struct iomap *iomap, bool use_fua, bool atomic_hw) { blk_opf_t opflags = REQ_SYNC | REQ_IDLE; @@ -329,7 +329,7 @@ static inline blk_opf_t iomap_dio_bio_opflags(struct iomap_dio *dio, opflags |= REQ_FUA; else dio->flags &= ~IOMAP_DIO_WRITE_THROUGH; - if (atomic) + if (atomic_hw) opflags |= REQ_ATOMIC; return opflags; @@ -340,8 +340,8 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio) const struct iomap *iomap = &iter->iomap; struct inode *inode = iter->inode; unsigned int fs_block_size = i_blocksize(inode), pad; + bool atomic_hw = iter->flags & IOMAP_ATOMIC_HW; const loff_t length = iomap_length(iter); - bool atomic = iter->flags & IOMAP_ATOMIC; loff_t pos = iter->pos; blk_opf_t bio_opf; struct bio *bio; @@ -351,7 +351,7 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio) u64 copied = 0; size_t orig_count; - if (atomic && length != fs_block_size) + if (atomic_hw && length != iter->len) return -EINVAL; if ((pos | length) & (bdev_logical_block_size(iomap->bdev) - 1) || @@ -428,7 +428,7 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio) goto out; } - bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua, atomic); + bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua, atomic_hw); nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, BIO_MAX_VECS); do { @@ -461,7 +461,7 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio) } n = bio->bi_iter.bi_size; - if (WARN_ON_ONCE(atomic && n != length)) { + if (WARN_ON_ONCE(atomic_hw && n != length)) { /* * This bio should have covered the complete length, * which it doesn't, so error. We may need to zero out @@ -652,9 +652,6 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iocb->ki_flags & IOCB_NOWAIT) iomi.flags |= IOMAP_NOWAIT; - if (iocb->ki_flags & IOCB_ATOMIC) - iomi.flags |= IOMAP_ATOMIC; - if (iov_iter_rw(iter) == READ) { /* reads can always complete inline */ dio->flags |= IOMAP_DIO_INLINE_COMP; @@ -689,6 +686,11 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, iomi.flags |= IOMAP_OVERWRITE_ONLY; } + if (dio_flags & IOMAP_DIO_ATOMIC_SW) + iomi.flags |= IOMAP_ATOMIC_SW; + else if (iocb->ki_flags & IOCB_ATOMIC) + iomi.flags |= IOMAP_ATOMIC_HW; + /* for data sync or sync, we need sync completion processing */ if (iocb_is_dsync(iocb)) { dio->flags |= IOMAP_DIO_NEED_SYNC; diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h index 9eab2c8ac3c5..69af89044ebd 100644 --- a/fs/iomap/trace.h +++ b/fs/iomap/trace.h @@ -99,7 +99,7 @@ DEFINE_RANGE_EVENT(iomap_dio_rw_queued); { IOMAP_FAULT, "FAULT" }, \ { IOMAP_DIRECT, "DIRECT" }, \ { IOMAP_NOWAIT, "NOWAIT" }, \ - { IOMAP_ATOMIC, "ATOMIC" } + { IOMAP_ATOMIC_HW, "ATOMIC_HW" } #define IOMAP_F_FLAGS_STRINGS \ { IOMAP_F_NEW, "NEW" }, \ diff --git a/include/linux/iomap.h b/include/linux/iomap.h index ea29388b2fba..9cd93530013c 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -189,8 +189,9 @@ struct iomap_folio_ops { #else #define IOMAP_DAX 0 #endif /* CONFIG_FS_DAX */ -#define IOMAP_ATOMIC (1 << 9) +#define IOMAP_ATOMIC_HW (1 << 9) /* HW-based torn-write protection */ #define IOMAP_DONTCACHE (1 << 10) +#define IOMAP_ATOMIC_SW (1 << 11)/* SW-based torn-write protection */ struct iomap_ops { /* @@ -502,6 +503,11 @@ struct iomap_dio_ops { */ #define IOMAP_DIO_PARTIAL (1 << 2) +/* + * Use software-based torn-write protection. + */ +#define IOMAP_DIO_ATOMIC_SW (1 << 3) + ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, unsigned int dio_flags, void *private, size_t done_before); |