From: Benjamin Coddington Date: Wed, 6 Jan 2016 15:40:18 +0000 (-0500) Subject: NFS: Use wait_on_atomic_t() for unlock after readahead X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=210c7c1750fdf769647d1d526c9ea34c412c9eee;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git NFS: Use wait_on_atomic_t() for unlock after readahead The use of wait_on_atomic_t() for waiting on I/O to complete before unlocking allows us to git rid of the NFS_IO_INPROGRESS flag, and thus the nfs_iocounter's flags member, and finally the nfs_iocounter altogether. The count of I/O is moved to the lock context, and the counter increment/decrement functions become simple enough to open-code. Signed-off-by: Benjamin Coddington [Trond: Fix up conflict with existing function nfs_wait_atomic_killable()] Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 178ec8da028f..4ef8f5addcad 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -756,7 +756,7 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) l_ctx = nfs_get_lock_context(nfs_file_open_context(filp)); if (!IS_ERR(l_ctx)) { - status = nfs_iocounter_wait(&l_ctx->io_count); + status = nfs_iocounter_wait(l_ctx); nfs_put_lock_context(l_ctx); if (status < 0) return status; diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 74fb1223c2f5..4b63d1bd5820 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -71,19 +71,25 @@ nfs_fattr_to_ino_t(struct nfs_fattr *fattr) return nfs_fileid_to_ino_t(fattr->fileid); } -/** - * nfs_wait_bit_killable - helper for functions that are sleeping on bit locks - * @word: long word containing the bit lock - */ -int nfs_wait_bit_killable(struct wait_bit_key *key, int mode) +static int nfs_wait_killable(int mode) { freezable_schedule_unsafe(); if (signal_pending_state(mode, current)) return -ERESTARTSYS; return 0; } + +int nfs_wait_bit_killable(struct wait_bit_key *key, int mode) +{ + return nfs_wait_killable(mode); +} EXPORT_SYMBOL_GPL(nfs_wait_bit_killable); +int nfs_wait_atomic_killable(atomic_t *p) +{ + return nfs_wait_killable(TASK_KILLABLE); +} + /** * nfs_compat_user_ino64 - returns the user-visible inode number * @fileid: 64-bit fileid @@ -699,7 +705,7 @@ static void nfs_init_lock_context(struct nfs_lock_context *l_ctx) l_ctx->lockowner.l_owner = current->files; l_ctx->lockowner.l_pid = current->tgid; INIT_LIST_HEAD(&l_ctx->list); - nfs_iocounter_init(&l_ctx->io_count); + atomic_set(&l_ctx->io_count, 0); } static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index ee81792d2886..4e8cc942336c 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -238,7 +238,7 @@ extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr, void (*release)(struct nfs_pgio_header *hdr)); void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos); -int nfs_iocounter_wait(struct nfs_io_counter *c); +int nfs_iocounter_wait(struct nfs_lock_context *l_ctx); extern const struct nfs_pageio_ops nfs_pgio_rw_ops; struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *); @@ -252,12 +252,6 @@ void nfs_free_request(struct nfs_page *req); struct nfs_pgio_mirror * nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc); -static inline void nfs_iocounter_init(struct nfs_io_counter *c) -{ - c->flags = 0; - atomic_set(&c->io_count, 0); -} - static inline bool nfs_pgio_has_mirroring(struct nfs_pageio_descriptor *desc) { WARN_ON_ONCE(desc->pg_mirror_count < 1); @@ -386,6 +380,7 @@ extern void nfs_clear_inode(struct inode *); extern void nfs_evict_inode(struct inode *); void nfs_zap_acl_cache(struct inode *inode); extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode); +extern int nfs_wait_atomic_killable(atomic_t *p); /* super.c */ extern const struct super_operations nfs_sops; diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index eeddbf0bf4c4..cb7e73ba059c 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -101,53 +101,18 @@ nfs_page_free(struct nfs_page *p) kmem_cache_free(nfs_page_cachep, p); } -static void -nfs_iocounter_inc(struct nfs_io_counter *c) -{ - atomic_inc(&c->io_count); -} - -static void -nfs_iocounter_dec(struct nfs_io_counter *c) -{ - if (atomic_dec_and_test(&c->io_count)) { - clear_bit(NFS_IO_INPROGRESS, &c->flags); - smp_mb__after_atomic(); - wake_up_bit(&c->flags, NFS_IO_INPROGRESS); - } -} - -static int -__nfs_iocounter_wait(struct nfs_io_counter *c) -{ - wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS); - DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS); - int ret = 0; - - do { - prepare_to_wait(wq, &q.wait, TASK_KILLABLE); - set_bit(NFS_IO_INPROGRESS, &c->flags); - if (atomic_read(&c->io_count) == 0) - break; - ret = nfs_wait_bit_killable(&q.key, TASK_KILLABLE); - } while (atomic_read(&c->io_count) != 0 && !ret); - finish_wait(wq, &q.wait); - return ret; -} - /** * nfs_iocounter_wait - wait for i/o to complete - * @c: nfs_io_counter to use + * @l_ctx: nfs_lock_context with io_counter to use * * returns -ERESTARTSYS if interrupted by a fatal signal. * Otherwise returns 0 once the io_count hits 0. */ int -nfs_iocounter_wait(struct nfs_io_counter *c) +nfs_iocounter_wait(struct nfs_lock_context *l_ctx) { - if (atomic_read(&c->io_count) == 0) - return 0; - return __nfs_iocounter_wait(c); + return wait_on_atomic_t(&l_ctx->io_count, nfs_wait_atomic_killable, + TASK_KILLABLE); } /* @@ -370,7 +335,7 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page, return ERR_CAST(l_ctx); } req->wb_lock_context = l_ctx; - nfs_iocounter_inc(&l_ctx->io_count); + atomic_inc(&l_ctx->io_count); /* Initialize the request struct. Initially, we assume a * long write-back delay. This will be adjusted in @@ -431,7 +396,8 @@ static void nfs_clear_request(struct nfs_page *req) req->wb_page = NULL; } if (l_ctx != NULL) { - nfs_iocounter_dec(&l_ctx->io_count); + if (atomic_dec_and_test(&l_ctx->io_count)) + wake_up_atomic_t(&l_ctx->io_count); nfs_put_lock_context(l_ctx); req->wb_lock_context = NULL; } diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 94828b3f8c95..8ba4f717b413 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1565,14 +1565,6 @@ static void nfs_writeback_result(struct rpc_task *task, } } -static int nfs_wait_atomic_killable(atomic_t *key) -{ - if (fatal_signal_pending(current)) - return -ERESTARTSYS; - freezable_schedule_unsafe(); - return 0; -} - static int wait_on_commit(struct nfs_mds_commit_info *cinfo) { return wait_on_atomic_t(&cinfo->rpcs_out, diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 9eee972863a7..196aaceafda7 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -60,18 +60,12 @@ struct nfs_lockowner { pid_t l_pid; }; -#define NFS_IO_INPROGRESS 0 -struct nfs_io_counter { - unsigned long flags; - atomic_t io_count; -}; - struct nfs_lock_context { atomic_t count; struct list_head list; struct nfs_open_context *open_context; struct nfs_lockowner lockowner; - struct nfs_io_counter io_count; + atomic_t io_count; }; struct nfs4_state;