diff options
Diffstat (limited to 'include/linux/netfs.h')
| -rw-r--r-- | include/linux/netfs.h | 362 |
1 files changed, 315 insertions, 47 deletions
diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 071d05d81d38..243c0f737938 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -21,7 +21,7 @@ #include <linux/rolling_buffer.h> enum netfs_sreq_ref_trace; -typedef struct mempool_s mempool_t; +typedef struct mempool mempool_t; struct folio_queue; /** @@ -48,11 +48,9 @@ enum netfs_io_source { NETFS_INVALID_READ, NETFS_UPLOAD_TO_SERVER, NETFS_WRITE_TO_CACHE, - NETFS_INVALID_WRITE, } __mode(byte); -typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error, - bool was_async); +typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error); /* * Per-inode context. This wraps the VFS inode. @@ -64,14 +62,13 @@ struct netfs_inode { struct fscache_cookie *cache; #endif struct mutex wb_lock; /* Writeback serialisation */ - loff_t remote_i_size; /* Size of the remote file */ - loff_t zero_point; /* Size after which we assume there's no data + loff_t _remote_i_size; /* Size of the remote file */ + loff_t _zero_point; /* Size after which we assume there's no data * on the server */ atomic_t io_count; /* Number of outstanding reqs */ unsigned long flags; #define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */ #define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */ -#define NETFS_ICTX_WRITETHROUGH 2 /* Write-through caching */ #define NETFS_ICTX_MODIFIED_ATTR 3 /* Indicate change in mtime/ctime */ #define NETFS_ICTX_SINGLE_NO_UPLOAD 4 /* Monolithic payload, cache but no upload */ }; @@ -143,16 +140,16 @@ struct netfs_io_stream { void (*issue_write)(struct netfs_io_subrequest *subreq); /* Collection tracking */ struct list_head subrequests; /* Contributory I/O operations */ - struct netfs_io_subrequest *front; /* Op being collected */ unsigned long long collected_to; /* Position we've collected results to */ size_t transferred; /* The amount transferred from this stream */ - enum netfs_io_source source; /* Where to read from/write to */ unsigned short error; /* Aggregate error for the stream */ + enum netfs_io_source source; /* Where to read from/write to */ unsigned char stream_nr; /* Index of stream in parent table */ bool avail; /* T if stream is available */ bool active; /* T if stream is active */ bool need_retry; /* T if this stream needs retrying */ bool failed; /* T if this stream failed */ + bool transferred_valid; /* T is ->transferred is valid */ }; /* @@ -191,7 +188,6 @@ struct netfs_io_subrequest { unsigned long flags; #define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */ #define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */ -#define NETFS_SREQ_SEEK_DATA_READ 3 /* Set if ->read() should SEEK_DATA first */ #define NETFS_SREQ_MADE_PROGRESS 4 /* Set if we transferred at least some data */ #define NETFS_SREQ_ONDEMAND 5 /* Set if it's from on-demand read mode */ #define NETFS_SREQ_BOUNDARY 6 /* Set if ends on hard boundary (eg. ceph object) */ @@ -207,6 +203,7 @@ enum netfs_io_origin { NETFS_READ_GAPS, /* This read is a synchronous read to fill gaps */ NETFS_READ_SINGLE, /* This read should be treated as a single object */ NETFS_READ_FOR_WRITE, /* This read is to prepare a write */ + NETFS_UNBUFFERED_READ, /* This is an unbuffered read */ NETFS_DIO_READ, /* This is a direct I/O read */ NETFS_WRITEBACK, /* This write was triggered by writepages */ NETFS_WRITEBACK_SINGLE, /* This monolithic write was triggered by writepages */ @@ -223,16 +220,18 @@ enum netfs_io_origin { */ struct netfs_io_request { union { - struct work_struct work; + struct work_struct cleanup_work; /* Deferred cleanup work */ struct rcu_head rcu; }; + struct work_struct work; /* Result collector work */ struct inode *inode; /* The file being accessed */ struct address_space *mapping; /* The mapping being accessed */ struct kiocb *iocb; /* AIO completion vector */ struct netfs_cache_resources cache_resources; struct netfs_io_request *copy_to_cache; /* Request to write just-read data to the cache */ - struct readahead_control *ractl; /* Readahead descriptor */ +#ifdef CONFIG_PROC_FS struct list_head proc_link; /* Link in netfs_iorequests */ +#endif struct netfs_io_stream io_streams[2]; /* Streams of parallel I/O operations */ #define NR_IO_STREAMS 2 //wreq->nr_io_streams struct netfs_group *group; /* Writeback group being written back */ @@ -243,46 +242,43 @@ struct netfs_io_request { void *netfs_priv; /* Private data for the netfs */ void *netfs_priv2; /* Private data for the netfs */ struct bio_vec *direct_bv; /* DIO buffer list (when handling iovec-iter) */ - unsigned int direct_bv_count; /* Number of elements in direct_bv[] */ - unsigned int debug_id; - unsigned int rsize; /* Maximum read size (0 for none) */ - unsigned int wsize; /* Maximum write size (0 for none) */ - atomic_t subreq_counter; /* Next subreq->debug_index */ - unsigned int nr_group_rel; /* Number of refs to release on ->group */ - spinlock_t lock; /* Lock for queuing subreqs */ unsigned long long submitted; /* Amount submitted for I/O so far */ unsigned long long len; /* Length of the request */ size_t transferred; /* Amount to be indicated as transferred */ long error; /* 0 or error that occurred */ - enum netfs_io_origin origin; /* Origin of the request */ - bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */ unsigned long long i_size; /* Size of the file */ unsigned long long start; /* Start position */ atomic64_t issued_to; /* Write issuer folio cursor */ unsigned long long collected_to; /* Point we've collected to */ unsigned long long cleaned_to; /* Position we've cleaned folios to */ unsigned long long abandon_to; /* Position to abandon folios to */ - pgoff_t no_unlock_folio; /* Don't unlock this folio after read */ + const struct folio *no_unlock_folio; /* Don't unlock this folio after read */ + unsigned int direct_bv_count; /* Number of elements in direct_bv[] */ + unsigned int debug_id; + unsigned int rsize; /* Maximum read size (0 for none) */ + unsigned int wsize; /* Maximum write size (0 for none) */ + atomic_t subreq_counter; /* Next subreq->debug_index */ + unsigned int nr_group_rel; /* Number of refs to release on ->group */ + spinlock_t lock; /* Lock for queuing subreqs */ unsigned char front_folio_order; /* Order (size) of front folio */ + enum netfs_io_origin origin; /* Origin of the request */ + bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */ refcount_t ref; unsigned long flags; -#define NETFS_RREQ_OFFLOAD_COLLECTION 0 /* Offload collection to workqueue */ -#define NETFS_RREQ_NO_UNLOCK_FOLIO 2 /* Don't unlock no_unlock_folio on completion */ -#define NETFS_RREQ_DONT_UNLOCK_FOLIOS 3 /* Don't unlock the folios on completion */ -#define NETFS_RREQ_FAILED 4 /* The request failed */ -#define NETFS_RREQ_IN_PROGRESS 5 /* Unlocked when the request completes */ -#define NETFS_RREQ_FOLIO_COPY_TO_CACHE 6 /* Copy current folio to cache from read */ -#define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */ -#define NETFS_RREQ_NONBLOCK 9 /* Don't block if possible (O_NONBLOCK) */ -#define NETFS_RREQ_BLOCKED 10 /* We blocked */ -#define NETFS_RREQ_PAUSE 11 /* Pause subrequest generation */ +#define NETFS_RREQ_IN_PROGRESS 0 /* Unlocked when the request completes (has ref) */ +#define NETFS_RREQ_ALL_QUEUED 1 /* All subreqs are now queued */ +#define NETFS_RREQ_PAUSE 2 /* Pause subrequest generation */ +#define NETFS_RREQ_FAILED 3 /* The request failed */ +#define NETFS_RREQ_RETRYING 4 /* Set if we're in the retry path */ +#define NETFS_RREQ_SHORT_TRANSFER 5 /* Set if we have a short transfer */ +#define NETFS_RREQ_OFFLOAD_COLLECTION 8 /* Offload collection to workqueue */ +#define NETFS_RREQ_NO_UNLOCK_FOLIO 9 /* Don't unlock no_unlock_folio on completion */ +#define NETFS_RREQ_FOLIO_COPY_TO_CACHE 10 /* Copy current folio to cache from read */ +#define NETFS_RREQ_UPLOAD_TO_SERVER 11 /* Need to write to the server */ #define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */ -#define NETFS_RREQ_ALL_QUEUED 13 /* All subreqs are now queued */ -#define NETFS_RREQ_NEED_RETRY 14 /* Need to try retrying */ #define NETFS_RREQ_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark * write to cache on read */ const struct netfs_request_ops *netfs_ops; - void (*cleanup)(struct netfs_io_request *req); }; /* @@ -321,7 +317,6 @@ struct netfs_request_ops { */ enum netfs_read_from_hole { NETFS_READ_HOLE_IGNORE, - NETFS_READ_HOLE_CLEAR, NETFS_READ_HOLE_FAIL, }; @@ -439,16 +434,14 @@ void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq); void netfs_get_subrequest(struct netfs_io_subrequest *subreq, enum netfs_sreq_ref_trace what); void netfs_put_subrequest(struct netfs_io_subrequest *subreq, - bool was_async, enum netfs_sreq_ref_trace what); + enum netfs_sreq_ref_trace what); ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len, struct iov_iter *new, iov_iter_extraction_t extraction_flags); size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset, size_t max_size, size_t max_segs); void netfs_prepare_write_failed(struct netfs_io_subrequest *subreq); -void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error, - bool was_async); -void netfs_queue_write_request(struct netfs_io_subrequest *subreq); +void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error); int netfs_start_io_read(struct inode *inode); void netfs_end_io_read(struct inode *inode); @@ -482,6 +475,254 @@ static inline struct netfs_inode *netfs_inode(struct inode *inode) } /** + * netfs_read_remote_i_size - Read remote_i_size safely + * @inode: The inode to access + * + * Read remote_i_size safely without the potential for tearing on 32-bit + * arches. + * + * NOTE: in a 32bit arch with a preemptable kernel and an UP compile the + * i_size_read/write must be atomic with respect to the local cpu (unlike with + * preempt disabled), but they don't need to be atomic with respect to other + * cpus like in true SMP (so they need either to either locally disable irq + * around the read or for example on x86 they can be still implemented as a + * cmpxchg8b without the need of the lock prefix). For SMP compiles and 64bit + * archs it makes no difference if preempt is enabled or not. + */ +static inline unsigned long long netfs_read_remote_i_size(const struct inode *inode) +{ + const struct netfs_inode *ictx = container_of(inode, struct netfs_inode, inode); + unsigned long long remote_i_size; + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + unsigned int seq; + + do { + seq = read_seqcount_begin(&inode->i_size_seqcount); + remote_i_size = ictx->_remote_i_size; + } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + remote_i_size = ictx->_remote_i_size; + preempt_enable(); +#else + /* Pairs with smp_store_release() in netfs_write_remote_i_size() */ + remote_i_size = smp_load_acquire(&ictx->_remote_i_size); +#endif + return remote_i_size; +} + +/* + * netfs_write_remote_i_size - Set remote_i_size safely + * @inode: The inode to access + * @remote_i_size: The new value for the size of the file on the server + * + * Set remote_i_size safely without the potential for tearing on 32-bit arches. + * + * Context: The caller must hold inode->i_lock. + * + * NOTE: unlike netfs_read_remote_i_size(), netfs_write_remote_i_size() does + * need locking around it (normally i_rwsem), otherwise on 32bit/SMP an update + * of i_size_seqcount can be lost, resulting in subsequent i_size_read() calls + * spinning forever. + */ +static inline void netfs_write_remote_i_size(struct inode *inode, + unsigned long long remote_i_size) +{ + struct netfs_inode *ictx = netfs_inode(inode); + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + write_seqcount_begin(&inode->i_size_seqcount); + ictx->_remote_i_size = remote_i_size; + write_seqcount_end(&inode->i_size_seqcount); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + ictx->_remote_i_size = remote_i_size; + preempt_enable(); +#else + /* + * Pairs with smp_load_acquire() in netfs_read_remote_i_size() to + * ensure changes related to inode size (such as page contents) are + * visible before we see the changed inode size. + */ + smp_store_release(&ictx->_remote_i_size, remote_i_size); +#endif +} + +/** + * netfs_read_zero_point - Read zero_point safely + * @inode: The inode to access + * + * Read zero_point safely without the potential for tearing on 32-bit + * arches. + * + * NOTE: in a 32bit arch with a preemptable kernel and an UP compile the + * i_size_read/write must be atomic with respect to the local cpu (unlike with + * preempt disabled), but they don't need to be atomic with respect to other + * cpus like in true SMP (so they need either to either locally disable irq + * around the read or for example on x86 they can be still implemented as a + * cmpxchg8b without the need of the lock prefix). For SMP compiles and 64bit + * archs it makes no difference if preempt is enabled or not. + */ +static inline unsigned long long netfs_read_zero_point(const struct inode *inode) +{ + struct netfs_inode *ictx = container_of(inode, struct netfs_inode, inode); + unsigned long long zero_point; + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + unsigned int seq; + + do { + seq = read_seqcount_begin(&inode->i_size_seqcount); + zero_point = ictx->_zero_point; + } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + zero_point = ictx->_zero_point; + preempt_enable(); +#else + /* Pairs with smp_store_release() in netfs_write_zero_point() */ + zero_point = smp_load_acquire(&ictx->_zero_point); +#endif + return zero_point; +} + +/* + * netfs_write_zero_point - Set zero_point safely + * @inode: The inode to access + * @zero_point: The new value for the point beyond which the server has no data + * + * Set zero_point safely without the potential for tearing on 32-bit arches. + * + * Context: The caller must hold inode->i_lock. + * + * NOTE: unlike netfs_read_zero_point(), netfs_write_zero_point() does need + * locking around it (normally i_rwsem), otherwise on 32bit/SMP an update of + * i_size_seqcount can be lost, resulting in subsequent read calls spinning + * forever. + */ +static inline void netfs_write_zero_point(struct inode *inode, + unsigned long long zero_point) +{ + struct netfs_inode *ictx = netfs_inode(inode); + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + write_seqcount_begin(&inode->i_size_seqcount); + ictx->_zero_point = zero_point; + write_seqcount_end(&inode->i_size_seqcount); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + ictx->_zero_point = zero_point; + preempt_enable(); +#else + /* + * Pairs with smp_load_acquire() in netfs_read_zero_point() to + * ensure changes related to inode size (such as page contents) are + * visible before we see the changed inode size. + */ + smp_store_release(&ictx->_zero_point, zero_point); +#endif +} + +/** + * netfs_read_sizes - Read remote_i_size and zero_point safely + * @inode: The inode to access + * @i_size: Where to return the local file size. + * @remote_i_size: Where to return the size of the file on the server + * @zero_point: Where to return the the point beyond which the server has no data + * + * Read remote_i_size and zero_point safely without the potential for tearing + * on 32-bit arches. + * + * NOTE: in a 32bit arch with a preemptable kernel and an UP compile the + * i_size_read/write must be atomic with respect to the local cpu (unlike with + * preempt disabled), but they don't need to be atomic with respect to other + * cpus like in true SMP (so they need either to either locally disable irq + * around the read or for example on x86 they can be still implemented as a + * cmpxchg8b without the need of the lock prefix). For SMP compiles and 64bit + * archs it makes no difference if preempt is enabled or not. + */ +static inline void netfs_read_sizes(const struct inode *inode, + unsigned long long *i_size, + unsigned long long *remote_i_size, + unsigned long long *zero_point) +{ + const struct netfs_inode *ictx = container_of(inode, struct netfs_inode, inode); +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + unsigned int seq; + + do { + seq = read_seqcount_begin(&inode->i_size_seqcount); + *i_size = inode->i_size; + *remote_i_size = ictx->_remote_i_size; + *zero_point = ictx->_zero_point; + } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + *i_size = inode->i_size; + *remote_i_size = ictx->_remote_i_size; + *zero_point = ictx->_zero_point; + preempt_enable(); +#else + /* Pairs with smp_store_release() in i_size_write() */ + *i_size = smp_load_acquire(&inode->i_size); + /* Pairs with smp_store_release() in netfs_write_remote_i_size() */ + *remote_i_size = smp_load_acquire(&ictx->_remote_i_size); + /* Pairs with smp_store_release() in netfs_write_zero_point() */ + *zero_point = smp_load_acquire(&ictx->_zero_point); +#endif +} + +/* + * netfs_write_sizes - Set i_size, remote_i_size and zero_point safely + * @inode: The inode to access + * @i_size: The new value for the local size of the file + * @remote_i_size: The new value for the size of the file on the server + * @zero_point: The new value for the point beyond which the server has no data + * + * Set both remote_i_size and zero_point safely without the potential for + * tearing on 32-bit arches. + * + * Context: The caller must hold inode->i_lock. + * + * NOTE: unlike netfs_read_zero_point(), netfs_write_zero_point() does need + * locking around it (normally i_rwsem), otherwise on 32bit/SMP an update of + * i_size_seqcount can be lost, resulting in subsequent read calls spinning + * forever. + */ +static inline void netfs_write_sizes(struct inode *inode, + unsigned long long i_size, + unsigned long long remote_i_size, + unsigned long long zero_point) +{ + struct netfs_inode *ictx = netfs_inode(inode); + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + write_seqcount_begin(&inode->i_size_seqcount); + inode->i_size = i_size; + ictx->_remote_i_size = remote_i_size; + ictx->_zero_point = zero_point; + write_seqcount_end(&inode->i_size_seqcount); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + inode->i_size = i_size; + ictx->_remote_i_size = remote_i_size; + ictx->_zero_point = zero_point; + preempt_enable(); +#else + /* + * Pairs with smp_load_acquire() in i_size_read(), + * netfs_read_remote_i_size() and netfs_read_zero_point() to ensure + * changes related to inode size (such as page contents) are visible + * before we see the changed inode size. + */ + smp_store_release(&inode->i_size, i_size); + smp_store_release(&ictx->_remote_i_size, remote_i_size); + smp_store_release(&ictx->_zero_point, zero_point); +#endif +} + +/** * netfs_inode_init - Initialise a netfslib inode context * @ctx: The netfs inode to initialise * @ops: The netfs's operations list @@ -495,8 +736,8 @@ static inline void netfs_inode_init(struct netfs_inode *ctx, bool use_zero_point) { ctx->ops = ops; - ctx->remote_i_size = i_size_read(&ctx->inode); - ctx->zero_point = LLONG_MAX; + ctx->_remote_i_size = i_size_read(&ctx->inode); + ctx->_zero_point = LLONG_MAX; ctx->flags = 0; atomic_set(&ctx->io_count, 0); #if IS_ENABLED(CONFIG_FSCACHE) @@ -505,7 +746,7 @@ static inline void netfs_inode_init(struct netfs_inode *ctx, mutex_init(&ctx->wb_lock); /* ->releasepage() drives zero_point */ if (use_zero_point) { - ctx->zero_point = ctx->remote_i_size; + ctx->_zero_point = ctx->_remote_i_size; mapping_set_release_always(ctx->inode.i_mapping); } } @@ -518,13 +759,40 @@ static inline void netfs_inode_init(struct netfs_inode *ctx, * * Inform the netfs lib that a file got resized so that it can adjust its state. */ -static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size, +static inline void netfs_resize_file(struct netfs_inode *ictx, + unsigned long long new_i_size, bool changed_on_server) { +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + struct inode *inode = &ictx->inode; + + preempt_disable(); + write_seqcount_begin(&inode->i_size_seqcount); if (changed_on_server) - ctx->remote_i_size = new_i_size; - if (new_i_size < ctx->zero_point) - ctx->zero_point = new_i_size; + ictx->_remote_i_size = new_i_size; + if (new_i_size < ictx->_zero_point) + ictx->_zero_point = new_i_size; + write_seqcount_end(&inode->i_size_seqcount); + preempt_enable(); +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) + preempt_disable(); + if (changed_on_server) + ictx->_remote_i_size = new_i_size; + if (new_i_size < ictx->_zero_point) + ictx->_zero_point = new_i_size; + preempt_enable(); +#else + /* + * Pairs with smp_load_acquire() in netfs_read_remote_i_size and + * netfs_read_zero_point() to ensure changes related to inode size + * (such as page contents) are visible before we see the changed inode + * size. + */ + if (changed_on_server) + smp_store_release(&ictx->_remote_i_size, new_i_size); + if (new_i_size < ictx->_zero_point) + smp_store_release(&ictx->_zero_point, new_i_size); +#endif } /** |