| Message ID | 20180920211842.13721-4-longli@linuxonhyperv.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V3,(resend),1/7] CIFS: pass page offsets on SMB1 read/write | expand |
чт, 20 сент. 2018 г. в 14:22, Long Li <longli@linuxonhyperv.com>: > > From: Long Li <longli@microsoft.com> > > With direct I/O write, user supplied buffers are pinned to the memory and data > are transferred directly from user buffers to the transport layer. > > Change in v3: add support for kernel AIO > > Signed-off-by: Long Li <longli@microsoft.com> > --- > fs/cifs/cifsfs.h | 1 + > fs/cifs/file.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++--------- > 2 files changed, 166 insertions(+), 31 deletions(-) > > diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h > index ed5479c..cc54051 100644 > --- a/fs/cifs/cifsfs.h > +++ b/fs/cifs/cifsfs.h > @@ -104,6 +104,7 @@ extern ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to); > extern ssize_t cifs_direct_readv(struct kiocb *iocb, struct iov_iter *to); > extern ssize_t cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to); > extern ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from); > +extern ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from); > extern ssize_t cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from); > extern int cifs_lock(struct file *, int, struct file_lock *); > extern int cifs_fsync(struct file *, loff_t, loff_t, int); > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 6a939fa..2a5d209 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -2537,6 +2537,8 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, > loff_t saved_offset = offset; > pid_t pid; > struct TCP_Server_Info *server; > + struct page **pagevec; > + size_t start; > > if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) > pid = open_file->pid; > @@ -2553,38 +2555,74 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, > if (rc) > break; > > - nr_pages = get_numpages(wsize, len, &cur_len); > - wdata = cifs_writedata_alloc(nr_pages, > + if (ctx->direct_io) { > + cur_len = iov_iter_get_pages_alloc( > + from, &pagevec, wsize, &start); > + if (cur_len < 0) { > + cifs_dbg(VFS, > + "direct_writev couldn't get user pages " > + "(rc=%zd) iter type %d iov_offset %zd count" > + " %zd\n", > + cur_len, from->type, > + from->iov_offset, from->count); > + dump_stack(); > + break; > + } > + iov_iter_advance(from, cur_len); > + > + nr_pages = (cur_len + start + PAGE_SIZE - 1) / PAGE_SIZE; > + > + wdata = cifs_writedata_direct_alloc(pagevec, > cifs_uncached_writev_complete); > - if (!wdata) { > - rc = -ENOMEM; > - add_credits_and_wake_if(server, credits, 0); > - break; > - } > + if (!wdata) { > + rc = -ENOMEM; > + add_credits_and_wake_if(server, credits, 0); > + break; > + } > > - rc = cifs_write_allocate_pages(wdata->pages, nr_pages); > - if (rc) { > - kfree(wdata); > - add_credits_and_wake_if(server, credits, 0); > - break; > - } > > - num_pages = nr_pages; > - rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); > - if (rc) { > - for (i = 0; i < nr_pages; i++) > - put_page(wdata->pages[i]); > - kfree(wdata); > - add_credits_and_wake_if(server, credits, 0); > - break; > - } > + wdata->page_offset = start; > + wdata->tailsz = > + nr_pages > 1 ? > + cur_len - (PAGE_SIZE - start) - > + (nr_pages - 2) * PAGE_SIZE : > + cur_len; > + } else { > + nr_pages = get_numpages(wsize, len, &cur_len); > + wdata = cifs_writedata_alloc(nr_pages, > + cifs_uncached_writev_complete); > + if (!wdata) { > + rc = -ENOMEM; > + add_credits_and_wake_if(server, credits, 0); > + break; > + } > > - /* > - * Bring nr_pages down to the number of pages we actually used, > - * and free any pages that we didn't use. > - */ > - for ( ; nr_pages > num_pages; nr_pages--) > - put_page(wdata->pages[nr_pages - 1]); > + rc = cifs_write_allocate_pages(wdata->pages, nr_pages); > + if (rc) { > + kfree(wdata); > + add_credits_and_wake_if(server, credits, 0); > + break; > + } > + > + num_pages = nr_pages; > + rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); > + if (rc) { > + for (i = 0; i < nr_pages; i++) > + put_page(wdata->pages[i]); > + kfree(wdata); > + add_credits_and_wake_if(server, credits, 0); > + break; > + } > + > + /* > + * Bring nr_pages down to the number of pages we actually used, > + * and free any pages that we didn't use. > + */ > + for ( ; nr_pages > num_pages; nr_pages--) > + put_page(wdata->pages[nr_pages - 1]); > + > + wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); > + } > > wdata->sync_mode = WB_SYNC_ALL; > wdata->nr_pages = nr_pages; > @@ -2593,7 +2631,6 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, > wdata->pid = pid; > wdata->bytes = cur_len; > wdata->pagesz = PAGE_SIZE; > - wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); > wdata->credits = credits; > wdata->ctx = ctx; > kref_get(&ctx->refcount); > @@ -2687,8 +2724,9 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) > kref_put(&wdata->refcount, cifs_uncached_writedata_release); > } > > - for (i = 0; i < ctx->npages; i++) > - put_page(ctx->bv[i].bv_page); > + if (!ctx->direct_io) > + for (i = 0; i < ctx->npages; i++) > + put_page(ctx->bv[i].bv_page); > > cifs_stats_bytes_written(tcon, ctx->total_len); > set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags); > @@ -2703,6 +2741,102 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) > complete(&ctx->done); > } > > +ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from) the same comment as for readv: this function is almost identical to cifs_user_writev, can't the latter be refactored to avoid code duplication? > +{ > + struct file *file = iocb->ki_filp; > + ssize_t total_written = 0; > + struct cifsFileInfo *cfile; > + struct cifs_tcon *tcon; > + struct cifs_sb_info *cifs_sb; > + struct TCP_Server_Info *server; > + size_t len = iov_iter_count(from); > + int rc; > + struct cifs_aio_ctx *ctx; > + > + /* > + * iov_iter_get_pages_alloc doesn't work with ITER_KVEC. > + * In this case, fall back to non-direct write function. > + * this could be improved by getting pages directly in ITER_KVEC > + */ > + if (from->type & ITER_KVEC) { > + cifs_dbg(FYI, "use non-direct cifs_user_writev for kvec I/O\n"); > + return cifs_user_writev(iocb, from); > + } > + > + rc = generic_write_checks(iocb, from); > + if (rc <= 0) > + return rc; > + > + cifs_sb = CIFS_FILE_SB(file); > + cfile = file->private_data; > + tcon = tlink_tcon(cfile->tlink); > + server = tcon->ses->server; > + > + if (!server->ops->async_writev) > + return -ENOSYS; > + > + ctx = cifs_aio_ctx_alloc(); > + if (!ctx) > + return -ENOMEM; > + > + ctx->cfile = cifsFileInfo_get(cfile); > + > + if (!is_sync_kiocb(iocb)) > + ctx->iocb = iocb; > + > + ctx->pos = iocb->ki_pos; > + > + ctx->direct_io = true; > + ctx->iter = *from; > + ctx->len = len; > + > + /* grab a lock here due to read response handlers can access ctx */ > + mutex_lock(&ctx->aio_mutex); > + > + rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, from, > + cfile, cifs_sb, &ctx->list, ctx); > + > + /* > + * If at least one write was successfully sent, then discard any rc > + * value from the later writes. If the other write succeeds, then > + * we'll end up returning whatever was written. If it fails, then > + * we'll get a new rc value from that. > + */ > + if (!list_empty(&ctx->list)) > + rc = 0; > + > + mutex_unlock(&ctx->aio_mutex); > + > + if (rc) { > + kref_put(&ctx->refcount, cifs_aio_ctx_release); > + return rc; > + } > + > + if (!is_sync_kiocb(iocb)) { > + kref_put(&ctx->refcount, cifs_aio_ctx_release); > + return -EIOCBQUEUED; > + } > + > + rc = wait_for_completion_killable(&ctx->done); > + if (rc) { > + mutex_lock(&ctx->aio_mutex); > + ctx->rc = rc = -EINTR; > + total_written = ctx->total_len; > + mutex_unlock(&ctx->aio_mutex); > + } else { > + rc = ctx->rc; > + total_written = ctx->total_len; > + } > + > + kref_put(&ctx->refcount, cifs_aio_ctx_release); > + > + if (unlikely(!total_written)) > + return rc; > + > + iocb->ki_pos += total_written; > + return total_written; > +} > + > ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) > { > struct file *file = iocb->ki_filp; > -- > 2.7.4 > -- Best regards, Pavel Shilovsky
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index ed5479c..cc54051 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -104,6 +104,7 @@ extern ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_direct_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from); +extern ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from); extern ssize_t cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from); extern int cifs_lock(struct file *, int, struct file_lock *); extern int cifs_fsync(struct file *, loff_t, loff_t, int); diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 6a939fa..2a5d209 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2537,6 +2537,8 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, loff_t saved_offset = offset; pid_t pid; struct TCP_Server_Info *server; + struct page **pagevec; + size_t start; if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) pid = open_file->pid; @@ -2553,38 +2555,74 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, if (rc) break; - nr_pages = get_numpages(wsize, len, &cur_len); - wdata = cifs_writedata_alloc(nr_pages, + if (ctx->direct_io) { + cur_len = iov_iter_get_pages_alloc( + from, &pagevec, wsize, &start); + if (cur_len < 0) { + cifs_dbg(VFS, + "direct_writev couldn't get user pages " + "(rc=%zd) iter type %d iov_offset %zd count" + " %zd\n", + cur_len, from->type, + from->iov_offset, from->count); + dump_stack(); + break; + } + iov_iter_advance(from, cur_len); + + nr_pages = (cur_len + start + PAGE_SIZE - 1) / PAGE_SIZE; + + wdata = cifs_writedata_direct_alloc(pagevec, cifs_uncached_writev_complete); - if (!wdata) { - rc = -ENOMEM; - add_credits_and_wake_if(server, credits, 0); - break; - } + if (!wdata) { + rc = -ENOMEM; + add_credits_and_wake_if(server, credits, 0); + break; + } - rc = cifs_write_allocate_pages(wdata->pages, nr_pages); - if (rc) { - kfree(wdata); - add_credits_and_wake_if(server, credits, 0); - break; - } - num_pages = nr_pages; - rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); - if (rc) { - for (i = 0; i < nr_pages; i++) - put_page(wdata->pages[i]); - kfree(wdata); - add_credits_and_wake_if(server, credits, 0); - break; - } + wdata->page_offset = start; + wdata->tailsz = + nr_pages > 1 ? + cur_len - (PAGE_SIZE - start) - + (nr_pages - 2) * PAGE_SIZE : + cur_len; + } else { + nr_pages = get_numpages(wsize, len, &cur_len); + wdata = cifs_writedata_alloc(nr_pages, + cifs_uncached_writev_complete); + if (!wdata) { + rc = -ENOMEM; + add_credits_and_wake_if(server, credits, 0); + break; + } - /* - * Bring nr_pages down to the number of pages we actually used, - * and free any pages that we didn't use. - */ - for ( ; nr_pages > num_pages; nr_pages--) - put_page(wdata->pages[nr_pages - 1]); + rc = cifs_write_allocate_pages(wdata->pages, nr_pages); + if (rc) { + kfree(wdata); + add_credits_and_wake_if(server, credits, 0); + break; + } + + num_pages = nr_pages; + rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); + if (rc) { + for (i = 0; i < nr_pages; i++) + put_page(wdata->pages[i]); + kfree(wdata); + add_credits_and_wake_if(server, credits, 0); + break; + } + + /* + * Bring nr_pages down to the number of pages we actually used, + * and free any pages that we didn't use. + */ + for ( ; nr_pages > num_pages; nr_pages--) + put_page(wdata->pages[nr_pages - 1]); + + wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); + } wdata->sync_mode = WB_SYNC_ALL; wdata->nr_pages = nr_pages; @@ -2593,7 +2631,6 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, wdata->pid = pid; wdata->bytes = cur_len; wdata->pagesz = PAGE_SIZE; - wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); wdata->credits = credits; wdata->ctx = ctx; kref_get(&ctx->refcount); @@ -2687,8 +2724,9 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) kref_put(&wdata->refcount, cifs_uncached_writedata_release); } - for (i = 0; i < ctx->npages; i++) - put_page(ctx->bv[i].bv_page); + if (!ctx->direct_io) + for (i = 0; i < ctx->npages; i++) + put_page(ctx->bv[i].bv_page); cifs_stats_bytes_written(tcon, ctx->total_len); set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags); @@ -2703,6 +2741,102 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) complete(&ctx->done); } +ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + ssize_t total_written = 0; + struct cifsFileInfo *cfile; + struct cifs_tcon *tcon; + struct cifs_sb_info *cifs_sb; + struct TCP_Server_Info *server; + size_t len = iov_iter_count(from); + int rc; + struct cifs_aio_ctx *ctx; + + /* + * iov_iter_get_pages_alloc doesn't work with ITER_KVEC. + * In this case, fall back to non-direct write function. + * this could be improved by getting pages directly in ITER_KVEC + */ + if (from->type & ITER_KVEC) { + cifs_dbg(FYI, "use non-direct cifs_user_writev for kvec I/O\n"); + return cifs_user_writev(iocb, from); + } + + rc = generic_write_checks(iocb, from); + if (rc <= 0) + return rc; + + cifs_sb = CIFS_FILE_SB(file); + cfile = file->private_data; + tcon = tlink_tcon(cfile->tlink); + server = tcon->ses->server; + + if (!server->ops->async_writev) + return -ENOSYS; + + ctx = cifs_aio_ctx_alloc(); + if (!ctx) + return -ENOMEM; + + ctx->cfile = cifsFileInfo_get(cfile); + + if (!is_sync_kiocb(iocb)) + ctx->iocb = iocb; + + ctx->pos = iocb->ki_pos; + + ctx->direct_io = true; + ctx->iter = *from; + ctx->len = len; + + /* grab a lock here due to read response handlers can access ctx */ + mutex_lock(&ctx->aio_mutex); + + rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, from, + cfile, cifs_sb, &ctx->list, ctx); + + /* + * If at least one write was successfully sent, then discard any rc + * value from the later writes. If the other write succeeds, then + * we'll end up returning whatever was written. If it fails, then + * we'll get a new rc value from that. + */ + if (!list_empty(&ctx->list)) + rc = 0; + + mutex_unlock(&ctx->aio_mutex); + + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } + + if (!is_sync_kiocb(iocb)) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return -EIOCBQUEUED; + } + + rc = wait_for_completion_killable(&ctx->done); + if (rc) { + mutex_lock(&ctx->aio_mutex); + ctx->rc = rc = -EINTR; + total_written = ctx->total_len; + mutex_unlock(&ctx->aio_mutex); + } else { + rc = ctx->rc; + total_written = ctx->total_len; + } + + kref_put(&ctx->refcount, cifs_aio_ctx_release); + + if (unlikely(!total_written)) + return rc; + + iocb->ki_pos += total_written; + return total_written; +} + ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp;