Hi David,
I have tested netfs integration with fsc mount option enabled. But, I
observed function "netfs_cache_prepare_read" always returns
"NETFS_DOWNLOAD_FROM_SERVER" because cres->ops(i.e cachefiles
operations) is not set.
static enum netfs_read_source netfs_cache_prepare_read(struct
netfs_read_subrequest *subreq,
loff_t i_size)
{
struct netfs_read_request *rreq = subreq->rreq;
struct netfs_cache_resources *cres = &rreq->cache_resources;
if (cres->ops)
return cres->ops->prepare_read(subreq, i_size);
if (subreq->start >= rreq->i_size)
return NETFS_FILL_WITH_ZEROES;
return NETFS_DOWNLOAD_FROM_SERVER;
I have used cifs-experimental branch in your repo to test netfs changes.
Please let me know if any work needs to be done for netfs to integrate
with cachefiles?
Regards,
Rohith
On Wed, Jan 26, 2022 at 1:24 AM David Howells <dhowells@xxxxxxxxxx> wrote:
>
>
> ---
>
> fs/cifs/Kconfig | 1
> fs/cifs/cifsfs.c | 6
> fs/cifs/cifsfs.h | 3
> fs/cifs/cifsglob.h | 6
> fs/cifs/cifssmb.c | 9 -
> fs/cifs/file.c | 824 ++++++++----------------------------------------
> fs/cifs/fscache.c | 31 --
> fs/cifs/fscache.h | 52 ---
> fs/cifs/inode.c | 17 +
> fs/cifs/smb2pdu.c | 15 +
> fs/netfs/read_helper.c | 7
> 11 files changed, 182 insertions(+), 789 deletions(-)
>
> diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
> index 3b7e3b9e4fd2..c47e2d3a101f 100644
> --- a/fs/cifs/Kconfig
> +++ b/fs/cifs/Kconfig
> @@ -2,6 +2,7 @@
> config CIFS
> tristate "SMB3 and CIFS support (advanced network filesystem)"
> depends on INET
> + select NETFS_SUPPORT
> select NLS
> select CRYPTO
> select CRYPTO_MD5
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index a56cb9c8c5ff..bd06df3bb24b 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -936,7 +936,7 @@ cifs_loose_read_iter(struct kiocb *iocb, struct iov_iter *iter)
> struct inode *inode = file_inode(iocb->ki_filp);
>
> if (iocb->ki_flags & IOCB_DIRECT)
> - return cifs_user_readv(iocb, iter);
> + return netfs_direct_read_iter(iocb, iter);
>
> rc = cifs_revalidate_mapping(inode);
> if (rc)
> @@ -1314,7 +1314,7 @@ const struct file_operations cifs_file_strict_ops = {
> };
>
> const struct file_operations cifs_file_direct_ops = {
> - .read_iter = cifs_direct_readv,
> + .read_iter = netfs_direct_read_iter,
> .write_iter = cifs_direct_writev,
> .open = cifs_open,
> .release = cifs_close,
> @@ -1370,7 +1370,7 @@ const struct file_operations cifs_file_strict_nobrl_ops = {
> };
>
> const struct file_operations cifs_file_direct_nobrl_ops = {
> - .read_iter = cifs_direct_readv,
> + .read_iter = netfs_direct_read_iter,
> .write_iter = cifs_direct_writev,
> .open = cifs_open,
> .release = cifs_close,
> diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
> index 1c77bbc0815f..c7d5c268fc47 100644
> --- a/fs/cifs/cifsfs.h
> +++ b/fs/cifs/cifsfs.h
> @@ -85,6 +85,7 @@ extern const struct inode_operations cifs_dfs_referral_inode_operations;
>
>
> /* Functions related to files and directories */
> +extern const struct netfs_request_ops cifs_req_ops;
> extern const struct file_operations cifs_file_ops;
> extern const struct file_operations cifs_file_direct_ops; /* if directio mnt */
> extern const struct file_operations cifs_file_strict_ops; /* if strictio mnt */
> @@ -94,8 +95,6 @@ extern const struct file_operations cifs_file_strict_nobrl_ops;
> extern int cifs_open(struct inode *inode, struct file *file);
> extern int cifs_close(struct inode *inode, struct file *file);
> extern int cifs_closedir(struct inode *inode, struct file *file);
> -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);
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 3a4fed645636..938e4e9827ed 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -1313,18 +1313,14 @@ struct cifs_aio_ctx {
>
> /* asynchronous read support */
> struct cifs_readdata {
> + struct netfs_read_subrequest *subreq;
> struct kref refcount;
> - struct list_head list;
> - struct completion done;
> struct cifsFileInfo *cfile;
> - struct address_space *mapping;
> - struct cifs_aio_ctx *ctx;
> __u64 offset;
> ssize_t got_bytes;
> unsigned int bytes;
> pid_t pid;
> int result;
> - struct work_struct work;
> struct iov_iter iter;
> struct kvec iov[2];
> struct TCP_Server_Info *server;
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index 38e7276352e2..c9fb77a8b31b 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -23,6 +23,7 @@
> #include <linux/swap.h>
> #include <linux/task_io_accounting_ops.h>
> #include <linux/uaccess.h>
> +#include <linux/netfs.h>
> #include "cifspdu.h"
> #include "cifsfs.h"
> #include "cifsglob.h"
> @@ -1609,7 +1610,13 @@ cifs_readv_callback(struct mid_q_entry *mid)
> rdata->result = -EIO;
> }
>
> - queue_work(cifsiod_wq, &rdata->work);
> + if (rdata->result == 0 || rdata->result == -EAGAIN)
> + iov_iter_advance(&rdata->subreq->iter, rdata->got_bytes);
> + netfs_subreq_terminated(rdata->subreq,
> + (rdata->result == 0 || rdata->result == -EAGAIN) ?
> + rdata->got_bytes : rdata->result,
> + false);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> DeleteMidQEntry(mid);
> add_credits(server, &credits, 0);
> }
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index f9b9a1562e17..36559de02e37 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -21,6 +21,7 @@
> #include <linux/slab.h>
> #include <linux/swap.h>
> #include <linux/mm.h>
> +#include <linux/netfs.h>
> #include <asm/div64.h>
> #include "cifsfs.h"
> #include "cifspdu.h"
> @@ -3306,12 +3307,8 @@ static struct cifs_readdata *cifs_readdata_alloc(work_func_t complete)
> struct cifs_readdata *rdata;
>
> rdata = kzalloc(sizeof(*rdata), GFP_KERNEL);
> - if (rdata) {
> + if (rdata)
> kref_init(&rdata->refcount);
> - INIT_LIST_HEAD(&rdata->list);
> - init_completion(&rdata->done);
> - INIT_WORK(&rdata->work, complete);
> - }
>
> return rdata;
> }
> @@ -3322,8 +3319,6 @@ cifs_readdata_release(struct kref *refcount)
> struct cifs_readdata *rdata = container_of(refcount,
> struct cifs_readdata, refcount);
>
> - if (rdata->ctx)
> - kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release);
> #ifdef CONFIG_CIFS_SMB_DIRECT
> if (rdata->mr) {
> smbd_deregister_mr(rdata->mr);
> @@ -3336,370 +3331,6 @@ cifs_readdata_release(struct kref *refcount)
> kfree(rdata);
> }
>
> -static void collect_uncached_read_data(struct cifs_aio_ctx *ctx);
> -
> -static void
> -cifs_uncached_readv_complete(struct work_struct *work)
> -{
> - struct cifs_readdata *rdata = container_of(work,
> - struct cifs_readdata, work);
> -
> - complete(&rdata->done);
> - collect_uncached_read_data(rdata->ctx);
> - /* the below call can possibly free the last ref to aio ctx */
> - kref_put(&rdata->refcount, cifs_readdata_release);
> -}
> -
> -static int cifs_resend_rdata(struct cifs_readdata *rdata,
> - struct list_head *rdata_list,
> - struct cifs_aio_ctx *ctx)
> -{
> - unsigned int rsize;
> - struct cifs_credits credits;
> - int rc;
> - struct TCP_Server_Info *server;
> -
> - /* XXX: should we pick a new channel here? */
> - server = rdata->server;
> -
> - do {
> - if (rdata->cfile->invalidHandle) {
> - rc = cifs_reopen_file(rdata->cfile, true);
> - if (rc == -EAGAIN)
> - continue;
> - else if (rc)
> - break;
> - }
> -
> - /*
> - * Wait for credits to resend this rdata.
> - * Note: we are attempting to resend the whole rdata not in
> - * segments
> - */
> - do {
> - rc = server->ops->wait_mtu_credits(server, rdata->bytes,
> - &rsize, &credits);
> -
> - if (rc)
> - goto fail;
> -
> - if (rsize < rdata->bytes) {
> - add_credits_and_wake_if(server, &credits, 0);
> - msleep(1000);
> - }
> - } while (rsize < rdata->bytes);
> - rdata->credits = credits;
> -
> - rc = adjust_credits(server, &rdata->credits, rdata->bytes);
> - if (!rc) {
> - if (rdata->cfile->invalidHandle)
> - rc = -EAGAIN;
> - else {
> -#ifdef CONFIG_CIFS_SMB_DIRECT
> - if (rdata->mr) {
> - rdata->mr->need_invalidate = true;
> - smbd_deregister_mr(rdata->mr);
> - rdata->mr = NULL;
> - }
> -#endif
> - rc = server->ops->async_readv(rdata);
> - }
> - }
> -
> - /* If the read was successfully sent, we are done */
> - if (!rc) {
> - /* Add to aio pending list */
> - list_add_tail(&rdata->list, rdata_list);
> - return 0;
> - }
> -
> - /* Roll back credits and retry if needed */
> - add_credits_and_wake_if(server, &rdata->credits, 0);
> - } while (rc == -EAGAIN);
> -
> -fail:
> - kref_put(&rdata->refcount, cifs_readdata_release);
> - return rc;
> -}
> -
> -static int
> -cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
> - struct cifs_sb_info *cifs_sb, struct list_head *rdata_list,
> - struct cifs_aio_ctx *ctx)
> -{
> - struct cifs_readdata *rdata;
> - unsigned int rsize;
> - struct cifs_credits credits_on_stack;
> - struct cifs_credits *credits = &credits_on_stack;
> - size_t cur_len;
> - int rc;
> - pid_t pid;
> - struct TCP_Server_Info *server;
> -
> - server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
> -
> - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> - pid = open_file->pid;
> - else
> - pid = current->tgid;
> -
> - do {
> - if (open_file->invalidHandle) {
> - rc = cifs_reopen_file(open_file, true);
> - if (rc == -EAGAIN)
> - continue;
> - else if (rc)
> - break;
> - }
> -
> - rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->rsize,
> - &rsize, credits);
> - if (rc)
> - break;
> -
> - cur_len = min_t(const size_t, len, rsize);
> -
> - rdata = cifs_readdata_alloc(cifs_uncached_readv_complete);
> - if (!rdata) {
> - add_credits_and_wake_if(server, credits, 0);
> - rc = -ENOMEM;
> - break;
> - }
> -
> - rdata->server = server;
> - rdata->cfile = cifsFileInfo_get(open_file);
> - rdata->offset = offset;
> - rdata->bytes = cur_len;
> - rdata->pid = pid;
> - rdata->credits = credits_on_stack;
> - rdata->ctx = ctx;
> - kref_get(&ctx->refcount);
> -
> - rdata->iter = ctx->iter;
> - iov_iter_advance(&rdata->iter, offset - ctx->pos);
> - iov_iter_truncate(&rdata->iter, cur_len);
> -
> - rc = adjust_credits(server, &rdata->credits, rdata->bytes);
> -
> - if (!rc) {
> - if (rdata->cfile->invalidHandle)
> - rc = -EAGAIN;
> - else
> - rc = server->ops->async_readv(rdata);
> - }
> -
> - if (rc) {
> - add_credits_and_wake_if(server, &rdata->credits, 0);
> - kref_put(&rdata->refcount, cifs_readdata_release);
> - if (rc == -EAGAIN)
> - continue;
> - break;
> - }
> -
> - list_add_tail(&rdata->list, rdata_list);
> - offset += cur_len;
> - len -= cur_len;
> - } while (len > 0);
> -
> - return rc;
> -}
> -
> -static void
> -collect_uncached_read_data(struct cifs_aio_ctx *ctx)
> -{
> - struct cifs_readdata *rdata, *tmp;
> - struct iov_iter *to = &ctx->iter;
> - struct cifs_sb_info *cifs_sb;
> - int rc;
> -
> - cifs_sb = CIFS_SB(ctx->cfile->dentry->d_sb);
> -
> - mutex_lock(&ctx->aio_mutex);
> -
> - if (list_empty(&ctx->list)) {
> - mutex_unlock(&ctx->aio_mutex);
> - return;
> - }
> -
> - rc = ctx->rc;
> - /* the loop below should proceed in the order of increasing offsets */
> -again:
> - list_for_each_entry_safe(rdata, tmp, &ctx->list, list) {
> - if (!rc) {
> - if (!try_wait_for_completion(&rdata->done)) {
> - mutex_unlock(&ctx->aio_mutex);
> - return;
> - }
> -
> - if (rdata->result == -EAGAIN) {
> - /* resend call if it's a retryable error */
> - struct list_head tmp_list;
> - unsigned int got_bytes = rdata->got_bytes;
> -
> - list_del_init(&rdata->list);
> - INIT_LIST_HEAD(&tmp_list);
> -
> - if (ctx->direct_io) {
> - /*
> - * Re-use rdata as this is a
> - * direct I/O
> - */
> - rc = cifs_resend_rdata(
> - rdata,
> - &tmp_list, ctx);
> - } else {
> - rc = cifs_send_async_read(
> - rdata->offset + got_bytes,
> - rdata->bytes - got_bytes,
> - rdata->cfile, cifs_sb,
> - &tmp_list, ctx);
> -
> - kref_put(&rdata->refcount,
> - cifs_readdata_release);
> - }
> -
> - list_splice(&tmp_list, &ctx->list);
> -
> - goto again;
> - } else if (rdata->result)
> - rc = rdata->result;
> -
> - /* if there was a short read -- discard anything left */
> - if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
> - rc = -ENODATA;
> -
> - ctx->total_len += rdata->got_bytes;
> - }
> - list_del_init(&rdata->list);
> - kref_put(&rdata->refcount, cifs_readdata_release);
> - }
> -
> - if (!ctx->direct_io)
> - ctx->total_len = ctx->len - iov_iter_count(to);
> -
> - /* mask nodata case */
> - if (rc == -ENODATA)
> - rc = 0;
> -
> - ctx->rc = (rc == 0) ? (ssize_t)ctx->total_len : rc;
> -
> - mutex_unlock(&ctx->aio_mutex);
> -
> - if (ctx->iocb && ctx->iocb->ki_complete)
> - ctx->iocb->ki_complete(ctx->iocb, ctx->rc);
> - else
> - complete(&ctx->done);
> -}
> -
> -static ssize_t __cifs_readv(
> - struct kiocb *iocb, struct iov_iter *to, bool direct)
> -{
> - size_t len;
> - struct file *file = iocb->ki_filp;
> - struct cifs_sb_info *cifs_sb;
> - struct cifsFileInfo *cfile;
> - struct cifs_tcon *tcon;
> - ssize_t rc, total_read = 0;
> - loff_t offset = iocb->ki_pos;
> - struct cifs_aio_ctx *ctx;
> -
> - /*
> - * iov_iter_get_pages_alloc() doesn't work with ITER_KVEC,
> - * fall back to data copy read path
> - * this could be improved by getting pages directly in ITER_KVEC
> - */
> - if (direct && iov_iter_is_kvec(to)) {
> - cifs_dbg(FYI, "use non-direct cifs_user_readv for kvec I/O\n");
> - direct = false;
> - }
> -
> - len = iov_iter_count(to);
> - if (!len)
> - return 0;
> -
> - cifs_sb = CIFS_FILE_SB(file);
> - cfile = file->private_data;
> - tcon = tlink_tcon(cfile->tlink);
> -
> - if (!tcon->ses->server->ops->async_readv)
> - return -ENOSYS;
> -
> - if ((file->f_flags & O_ACCMODE) == O_WRONLY)
> - cifs_dbg(FYI, "attempting read on write only file instance\n");
> -
> - ctx = cifs_aio_ctx_alloc();
> - if (!ctx)
> - return -ENOMEM;
> -
> - ctx->pos = offset;
> - ctx->direct_io = direct;
> - ctx->len = len;
> - ctx->cfile = cifsFileInfo_get(cfile);
> -
> - if (!is_sync_kiocb(iocb))
> - ctx->iocb = iocb;
> -
> - if (iter_is_iovec(to))
> - ctx->should_dirty = true;
> -
> - rc = extract_iter_to_iter(to, len, &ctx->iter, &ctx->bv);
> - if (rc < 0) {
> - kref_put(&ctx->refcount, cifs_aio_ctx_release);
> - return rc;
> - }
> - ctx->npages = rc;
> -
> - /* grab a lock here due to read response handlers can access ctx */
> - mutex_lock(&ctx->aio_mutex);
> -
> - rc = cifs_send_async_read(offset, len, cfile, cifs_sb, &ctx->list, ctx);
> -
> - /* if at least one read request send succeeded, then reset rc */
> - 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_read = ctx->total_len;
> - mutex_unlock(&ctx->aio_mutex);
> - } else {
> - rc = ctx->rc;
> - total_read = ctx->total_len;
> - }
> -
> - kref_put(&ctx->refcount, cifs_aio_ctx_release);
> -
> - if (total_read) {
> - iocb->ki_pos += total_read;
> - return total_read;
> - }
> - return rc;
> -}
> -
> -ssize_t cifs_direct_readv(struct kiocb *iocb, struct iov_iter *to)
> -{
> - return __cifs_readv(iocb, to, true);
> -}
> -
> -ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
> -{
> - return __cifs_readv(iocb, to, false);
> -}
> -
> ssize_t
> cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
> {
> @@ -3720,12 +3351,15 @@ cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
> * pos+len-1.
> */
> if (!CIFS_CACHE_READ(cinode))
> - return cifs_user_readv(iocb, to);
> + return netfs_direct_read_iter(iocb, to);
>
> if (cap_unix(tcon->ses) &&
> (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
> - ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
> + ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
> + if (iocb->ki_flags & IOCB_DIRECT)
> + return netfs_direct_read_iter(iocb, to);
> return generic_file_read_iter(iocb, to);
> + }
>
> /*
> * We need to hold the sem to be sure nobody modifies lock list
> @@ -3734,104 +3368,16 @@ cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
> down_read(&cinode->lock_sem);
> if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
> tcon->ses->server->vals->shared_lock_type,
> - 0, NULL, CIFS_READ_OP))
> - rc = generic_file_read_iter(iocb, to);
> + 0, NULL, CIFS_READ_OP)) {
> + if (iocb->ki_flags & IOCB_DIRECT)
> + rc = netfs_direct_read_iter(iocb, to);
> + else
> + rc = generic_file_read_iter(iocb, to);
> + }
> up_read(&cinode->lock_sem);
> return rc;
> }
>
> -static ssize_t
> -cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
> -{
> - int rc = -EACCES;
> - unsigned int bytes_read = 0;
> - unsigned int total_read;
> - unsigned int current_read_size;
> - unsigned int rsize;
> - struct cifs_sb_info *cifs_sb;
> - struct cifs_tcon *tcon;
> - struct TCP_Server_Info *server;
> - unsigned int xid;
> - char *cur_offset;
> - struct cifsFileInfo *open_file;
> - struct cifs_io_parms io_parms = {0};
> - int buf_type = CIFS_NO_BUFFER;
> - __u32 pid;
> -
> - xid = get_xid();
> - cifs_sb = CIFS_FILE_SB(file);
> -
> - /* FIXME: set up handlers for larger reads and/or convert to async */
> - rsize = min_t(unsigned int, cifs_sb->ctx->rsize, CIFSMaxBufSize);
> -
> - if (file->private_data == NULL) {
> - rc = -EBADF;
> - free_xid(xid);
> - return rc;
> - }
> - open_file = file->private_data;
> - tcon = tlink_tcon(open_file->tlink);
> - server = cifs_pick_channel(tcon->ses);
> -
> - if (!server->ops->sync_read) {
> - free_xid(xid);
> - return -ENOSYS;
> - }
> -
> - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> - pid = open_file->pid;
> - else
> - pid = current->tgid;
> -
> - if ((file->f_flags & O_ACCMODE) == O_WRONLY)
> - cifs_dbg(FYI, "attempting read on write only file instance\n");
> -
> - for (total_read = 0, cur_offset = read_data; read_size > total_read;
> - total_read += bytes_read, cur_offset += bytes_read) {
> - do {
> - current_read_size = min_t(uint, read_size - total_read,
> - rsize);
> - /*
> - * For windows me and 9x we do not want to request more
> - * than it negotiated since it will refuse the read
> - * then.
> - */
> - if (!(tcon->ses->capabilities &
> - tcon->ses->server->vals->cap_large_files)) {
> - current_read_size = min_t(uint,
> - current_read_size, CIFSMaxBufSize);
> - }
> - if (open_file->invalidHandle) {
> - rc = cifs_reopen_file(open_file, true);
> - if (rc != 0)
> - break;
> - }
> - io_parms.pid = pid;
> - io_parms.tcon = tcon;
> - io_parms.offset = *offset;
> - io_parms.length = current_read_size;
> - io_parms.server = server;
> - rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
> - &bytes_read, &cur_offset,
> - &buf_type);
> - } while (rc == -EAGAIN);
> -
> - if (rc || (bytes_read == 0)) {
> - if (total_read) {
> - break;
> - } else {
> - free_xid(xid);
> - return rc;
> - }
> - } else {
> - cifs_stats_bytes_read(tcon, total_read);
> - *offset += bytes_read;
> - }
> - }
> - free_xid(xid);
> - return total_read;
> -}
> -
> /*
> * If the page is mmap'ed into a process' page tables, then we need to make
> * sure that it doesn't change while being written back.
> @@ -3901,224 +3447,149 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
> }
>
> /*
> - * Unlock a bunch of folios in the pagecache.
> + * Issue a read operation on behalf of the netfs helper functions. We're asked
> + * to make a read of a certain size at a point in the file. We are permitted
> + * to only read a portion of that, but as long as we read something, the netfs
> + * helper will call us again so that we can issue another read.
> */
> -static void cifs_unlock_folios(struct address_space *mapping, pgoff_t first, pgoff_t last)
> -{
> - struct folio *folio;
> - XA_STATE(xas, &mapping->i_pages, first);
> -
> - rcu_read_lock();
> - xas_for_each(&xas, folio, last) {
> - folio_unlock(folio);
> - }
> - rcu_read_unlock();
> -}
> -
> -static void cifs_readahead_complete(struct work_struct *work)
> -{
> - struct cifs_readdata *rdata = container_of(work,
> - struct cifs_readdata, work);
> - struct folio *folio;
> - pgoff_t last;
> - bool good = rdata->result == 0 || (rdata->result == -EAGAIN && rdata->got_bytes);
> -
> - XA_STATE(xas, &rdata->mapping->i_pages, rdata->offset / PAGE_SIZE);
> -
> -#if 0
> - if (good)
> - cifs_readpage_to_fscache(rdata->mapping->host, page);
> -#endif
> -
> - if (iov_iter_count(&rdata->iter) > 0)
> - iov_iter_zero(iov_iter_count(&rdata->iter), &rdata->iter);
> -
> - last = round_down(rdata->offset + rdata->got_bytes - 1, PAGE_SIZE);
> -
> - xas_for_each(&xas, folio, last) {
> - if (good) {
> - flush_dcache_folio(folio);
> - folio_mark_uptodate(folio);
> - }
> - folio_unlock(folio);
> - }
> -
> - kref_put(&rdata->refcount, cifs_readdata_release);
> -}
> -
> -static void cifs_readahead(struct readahead_control *ractl)
> +static void cifs_req_issue_op(struct netfs_read_subrequest *subreq)
> {
> - struct cifsFileInfo *open_file = ractl->file->private_data;
> - struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(ractl->file);
> + struct netfs_read_request *rreq = subreq->rreq;
> struct TCP_Server_Info *server;
> + struct cifs_readdata *rdata;
> + struct cifsFileInfo *open_file = rreq->netfs_priv;
> + struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb);
> + struct cifs_credits credits_on_stack, *credits = &credits_on_stack;
> unsigned int xid;
> pid_t pid;
> int rc = 0;
> + unsigned int rsize;
>
> xid = get_xid();
>
> if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> pid = open_file->pid;
> else
> - pid = current->tgid;
> + pid = current->tgid; // Ummm... This may be a workqueue
>
> server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
>
> - cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
> - __func__, ractl->file, ractl->mapping, readahead_count(ractl));
> -
> - /*
> - * Chop the readahead request up into rsize-sized read requests.
> - */
> - while (readahead_count(ractl) - ractl->_batch_count) {
> - unsigned int i, nr_pages, rsize;
> - struct cifs_readdata *rdata;
> - struct cifs_credits credits_on_stack;
> - struct cifs_credits *credits = &credits_on_stack;
> + cifs_dbg(FYI, "%s: op=%08x[%x] mapping=%p len=%zu/%zu\n",
> + __func__, rreq->debug_id, subreq->debug_index, rreq->mapping,
> + subreq->transferred, subreq->len);
>
> - if (open_file->invalidHandle) {
> + if (open_file->invalidHandle) {
> + do {
> rc = cifs_reopen_file(open_file, true);
> - if (rc) {
> - if (rc == -EAGAIN)
> - continue;
> - break;
> - }
> - }
> -
> - rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->rsize,
> - &rsize, credits);
> + } while (rc == -EAGAIN);
> if (rc)
> - break;
> - nr_pages = min_t(size_t, rsize / PAGE_SIZE, readahead_count(ractl));
> -
> - /*
> - * Give up immediately if rsize is too small to read an entire
> - * page. The VFS will fall back to readpage. We should never
> - * reach this point however since we set ra_pages to 0 when the
> - * rsize is smaller than a cache page.
> - */
> - if (unlikely(!nr_pages)) {
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> -
> - rdata = cifs_readdata_alloc(cifs_readahead_complete);
> - if (!rdata) {
> - /* best to give up if we're out of mem */
> - add_credits_and_wake_if(server, credits, 0);
> - break;
> - }
> + goto out;
> + }
>
> - rdata->offset = readahead_pos(ractl);
> - rdata->bytes = nr_pages * PAGE_SIZE;
> - rdata->cfile = cifsFileInfo_get(open_file);
> - rdata->server = server;
> - rdata->mapping = ractl->mapping;
> - rdata->pid = pid;
> - rdata->credits = credits_on_stack;
> + rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->rsize, &rsize, credits);
> + if (rc)
> + goto out;
>
> - for (i = 0; i < nr_pages; i++)
> - if (!readahead_folio(ractl))
> - BUG();
> + rdata = cifs_readdata_alloc(NULL);
> + if (!rdata) {
> + add_credits_and_wake_if(server, credits, 0);
> + rc = -ENOMEM;
> + goto out;
> + }
>
> - iov_iter_xarray(&rdata->iter, READ, &rdata->mapping->i_pages,
> - rdata->offset, rdata->bytes);
> + __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
> + rdata->subreq = subreq;
> + rdata->cfile = cifsFileInfo_get(open_file);
> + rdata->server = server;
> + rdata->offset = subreq->start + subreq->transferred;
> + rdata->bytes = subreq->len - subreq->transferred;
> + rdata->pid = pid;
> + rdata->credits = credits_on_stack;
> + rdata->iter = subreq->iter;
>
> - rc = adjust_credits(server, &rdata->credits, rdata->bytes);
> - if (!rc) {
> - if (rdata->cfile->invalidHandle)
> - rc = -EAGAIN;
> - else
> - rc = server->ops->async_readv(rdata);
> - }
> + rc = adjust_credits(server, &rdata->credits, rdata->bytes);
> + if (!rc) {
> + if (rdata->cfile->invalidHandle)
> + rc = -EAGAIN;
> + else
> + rc = server->ops->async_readv(rdata);
> + }
>
> - if (rc) {
> - add_credits_and_wake_if(server, &rdata->credits, 0);
> - cifs_unlock_folios(rdata->mapping,
> - rdata->offset / PAGE_SIZE,
> - (rdata->offset + rdata->bytes - 1) / PAGE_SIZE);
> - /* Fallback to the readpage in error/reconnect cases */
> - kref_put(&rdata->refcount, cifs_readdata_release);
> - break;
> - }
> + if (rc) {
> + add_credits_and_wake_if(server, &rdata->credits, 0);
> + /* Fallback to the readpage in error/reconnect cases */
> + kref_put(&rdata->refcount, cifs_readdata_release);
> + goto out;
> }
>
> + kref_put(&rdata->refcount, cifs_readdata_release);
> +
> +out:
> free_xid(xid);
> + if (rc)
> + netfs_subreq_terminated(subreq, rc, false);
> +}
> +
> +static int cifs_init_rreq(struct netfs_read_request *rreq, struct file *file)
> +{
> + rreq->netfs_priv = file->private_data;
> + return 0;
> }
>
> /*
> - * cifs_readpage_worker must be called with the page pinned
> + * Expand the size of a readahead to the size of the rsize, if at least as
> + * large as a page, allowing for the possibility that rsize is not pow-2
> + * aligned.
> */
> -static int cifs_readpage_worker(struct file *file, struct page *page,
> - loff_t *poffset)
> +static void cifs_expand_readahead(struct netfs_read_request *rreq)
> {
> - char *read_data;
> - int rc;
> + struct cifs_sb_info *cifs_sb = CIFS_SB(rreq->inode->i_sb);
> + unsigned int rsize = cifs_sb->ctx->rsize;
> + loff_t misalignment, i_size = i_size_read(rreq->inode);
>
> - /* Is the page cached? */
> - rc = cifs_readpage_from_fscache(file_inode(file), page);
> - if (rc == 0)
> - goto read_complete;
> -
> - read_data = kmap(page);
> - /* for reads over a certain size could initiate async read ahead */
> -
> - rc = cifs_read(file, read_data, PAGE_SIZE, poffset);
> -
> - if (rc < 0)
> - goto io_error;
> - else
> - cifs_dbg(FYI, "Bytes read %d\n", rc);
> + if (rsize < PAGE_SIZE)
> + return;
>
> - /* we do not want atime to be less than mtime, it broke some apps */
> - file_inode(file)->i_atime = current_time(file_inode(file));
> - if (timespec64_compare(&(file_inode(file)->i_atime), &(file_inode(file)->i_mtime)))
> - file_inode(file)->i_atime = file_inode(file)->i_mtime;
> + if (rsize < INT_MAX)
> + rsize = roundup_pow_of_two(rsize);
> else
> - file_inode(file)->i_atime = current_time(file_inode(file));
> + rsize = ((unsigned int)INT_MAX + 1) / 2;
>
> - if (PAGE_SIZE > rc)
> - memset(read_data + rc, 0, PAGE_SIZE - rc);
> -
> - flush_dcache_page(page);
> - SetPageUptodate(page);
> -
> - /* send this page to the cache */
> - cifs_readpage_to_fscache(file_inode(file), page);
> -
> - rc = 0;
> -
> -io_error:
> - kunmap(page);
> - unlock_page(page);
> + misalignment = rreq->start & (rsize - 1);
> + if (misalignment) {
> + rreq->start -= misalignment;
> + rreq->len += misalignment;
> + }
>
> -read_complete:
> - return rc;
> + rreq->len = round_up(rreq->len, rsize);
> + if (rreq->start < i_size && rreq->len > i_size - rreq->start)
> + rreq->len = i_size - rreq->start;
> }
>
> -static int cifs_readpage(struct file *file, struct page *page)
> +static void cifs_rreq_done(struct netfs_read_request *rreq)
> {
> - loff_t offset = page_file_offset(page);
> - int rc = -EACCES;
> - unsigned int xid;
> + struct inode *inode = rreq->inode;
>
> - xid = get_xid();
> -
> - if (file->private_data == NULL) {
> - rc = -EBADF;
> - free_xid(xid);
> - return rc;
> - }
> -
> - cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
> - page, (int)offset, (int)offset);
> -
> - rc = cifs_readpage_worker(file, page, &offset);
> + /* we do not want atime to be less than mtime, it broke some apps */
> + inode->i_atime = current_time(inode);
> + if (timespec64_compare(&inode->i_atime, &inode->i_mtime))
> + inode->i_atime = inode->i_mtime;
> + else
> + inode->i_atime = current_time(inode);
> +}
>
> - free_xid(xid);
> - return rc;
> +static void cifs_req_cleanup(struct address_space *mapping, void *netfs_priv)
> +{
> }
>
> +const struct netfs_request_ops cifs_req_ops = {
> + .init_rreq = cifs_init_rreq,
> + .expand_readahead = cifs_expand_readahead,
> + .issue_op = cifs_req_issue_op,
> + .done = cifs_rreq_done,
> + .cleanup = cifs_req_cleanup,
> +};
> +
> static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
> {
> struct cifsFileInfo *open_file;
> @@ -4168,34 +3639,20 @@ static int cifs_write_begin(struct file *file, struct address_space *mapping,
> loff_t pos, unsigned len, unsigned flags,
> struct page **pagep, void **fsdata)
> {
> - int oncethru = 0;
> - pgoff_t index = pos >> PAGE_SHIFT;
> - loff_t offset = pos & (PAGE_SIZE - 1);
> - loff_t page_start = pos & PAGE_MASK;
> - loff_t i_size;
> - struct page *page;
> - int rc = 0;
> + struct folio *folio;
> + int rc;
>
> cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
>
> -start:
> - page = grab_cache_page_write_begin(mapping, index, flags);
> - if (!page) {
> - rc = -ENOMEM;
> - goto out;
> - }
> -
> - if (PageUptodate(page))
> - goto out;
> -
> - /*
> - * If we write a full page it will be up to date, no need to read from
> - * the server. If the write is short, we'll end up doing a sync write
> - * instead.
> + /* Prefetch area to be written into the cache if we're caching this
> + * file. We need to do this before we get a lock on the page in case
> + * there's more than one writer competing for the same cache block.
> */
> - if (len == PAGE_SIZE)
> - goto out;
> + rc = netfs_write_begin(file, mapping, pos, len, flags, &folio, fsdata);
> + if (rc < 0)
> + return rc;
>
> +#if 0
> /*
> * optimize away the read when we have an oplock, and we're not
> * expecting to use any of the data we'd be reading in. That
> @@ -4210,34 +3667,17 @@ static int cifs_write_begin(struct file *file, struct address_space *mapping,
> offset + len,
> PAGE_SIZE);
> /*
> - * PageChecked means that the parts of the page
> - * to which we're not writing are considered up
> - * to date. Once the data is copied to the
> - * page, it can be set uptodate.
> + * Marking a folio checked means that the parts of the
> + * page to which we're not writing are considered up to
> + * date. Once the data is copied to the page, it can be
> + * set uptodate.
> */
> - SetPageChecked(page);
> + folio_set_checked(folio);
> goto out;
> }
> }
> -
> - if ((file->f_flags & O_ACCMODE) != O_WRONLY && !oncethru) {
> - /*
> - * might as well read a page, it is fast enough. If we get
> - * an error, we don't need to return it. cifs_write_end will
> - * do a sync write instead since PG_uptodate isn't set.
> - */
> - cifs_readpage_worker(file, page, &page_start);
> - put_page(page);
> - oncethru = 1;
> - goto start;
> - } else {
> - /* we could try using another file handle if there is one -
> - but how would we lock it to prevent close of that handle
> - racing with this read? In any case
> - this will be written out by write_end so is fine */
> - }
> -out:
> - *pagep = page;
> +#endif
> + *pagep = folio_page(folio, (pos - folio_pos(folio)) / PAGE_SIZE);
> return rc;
> }
>
> @@ -4429,8 +3869,8 @@ static int cifs_set_page_dirty(struct page *page)
> #endif
>
> const struct address_space_operations cifs_addr_ops = {
> - .readpage = cifs_readpage,
> - .readahead = cifs_readahead,
> + .readpage = netfs_readpage,
> + .readahead = netfs_readahead,
> .writepage = cifs_writepage,
> .writepages = cifs_writepages,
> .write_begin = cifs_write_begin,
> @@ -4455,7 +3895,7 @@ const struct address_space_operations cifs_addr_ops = {
> * to leave cifs_readpages out of the address space operations.
> */
> const struct address_space_operations cifs_addr_ops_smallbuf = {
> - .readpage = cifs_readpage,
> + .readpage = netfs_readpage,
> .writepage = cifs_writepage,
> .writepages = cifs_writepages,
> .write_begin = cifs_write_begin,
> diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
> index a7e7e5a97b7f..bb1c3a372de4 100644
> --- a/fs/cifs/fscache.c
> +++ b/fs/cifs/fscache.c
> @@ -134,34 +134,3 @@ void cifs_fscache_release_inode_cookie(struct inode *inode)
> cifsi->netfs_ctx.cache = NULL;
> }
> }
> -
> -/*
> - * Retrieve a page from FS-Cache
> - */
> -int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
> -{
> - cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
> - __func__, cifs_inode_cookie(inode), page, inode);
> - return -ENOBUFS; // Needs conversion to using netfslib
> -}
> -
> -/*
> - * Retrieve a set of pages from FS-Cache
> - */
> -int __cifs_readpages_from_fscache(struct inode *inode,
> - struct address_space *mapping,
> - struct list_head *pages,
> - unsigned *nr_pages)
> -{
> - cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
> - __func__, cifs_inode_cookie(inode), *nr_pages, inode);
> - return -ENOBUFS; // Needs conversion to using netfslib
> -}
> -
> -void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
> -{
> - cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
> - __func__, cifs_inode_cookie(inode), page, inode);
> -
> - // Needs conversion to using netfslib
> -}
> diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
> index 9f6e42e85d14..fdc03cd7b881 100644
> --- a/fs/cifs/fscache.h
> +++ b/fs/cifs/fscache.h
> @@ -58,14 +58,6 @@ void cifs_fscache_fill_coherency(struct inode *inode,
> }
>
>
> -extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
> -extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
> -extern int __cifs_readpages_from_fscache(struct inode *,
> - struct address_space *,
> - struct list_head *,
> - unsigned *);
> -extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
> -
> static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
> {
> return netfs_i_cookie(inode);
> @@ -80,33 +72,6 @@ static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags
> i_size_read(inode), flags);
> }
>
> -static inline int cifs_readpage_from_fscache(struct inode *inode,
> - struct page *page)
> -{
> - if (cifs_inode_cookie(inode))
> - return __cifs_readpage_from_fscache(inode, page);
> -
> - return -ENOBUFS;
> -}
> -
> -static inline int cifs_readpages_from_fscache(struct inode *inode,
> - struct address_space *mapping,
> - struct list_head *pages,
> - unsigned *nr_pages)
> -{
> - if (cifs_inode_cookie(inode))
> - return __cifs_readpages_from_fscache(inode, mapping, pages,
> - nr_pages);
> - return -ENOBUFS;
> -}
> -
> -static inline void cifs_readpage_to_fscache(struct inode *inode,
> - struct page *page)
> -{
> - if (PageFsCache(page))
> - __cifs_readpage_to_fscache(inode, page);
> -}
> -
> #else /* CONFIG_CIFS_FSCACHE */
> static inline
> void cifs_fscache_fill_coherency(struct inode *inode,
> @@ -123,23 +88,6 @@ static inline void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool upd
> static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
> static inline void cifs_invalidate_cache(struct inode *inode, unsigned int flags) {}
>
> -static inline int
> -cifs_readpage_from_fscache(struct inode *inode, struct page *page)
> -{
> - return -ENOBUFS;
> -}
> -
> -static inline int cifs_readpages_from_fscache(struct inode *inode,
> - struct address_space *mapping,
> - struct list_head *pages,
> - unsigned *nr_pages)
> -{
> - return -ENOBUFS;
> -}
> -
> -static inline void cifs_readpage_to_fscache(struct inode *inode,
> - struct page *page) {}
> -
> #endif /* CONFIG_CIFS_FSCACHE */
>
> #endif /* _CIFS_FSCACHE_H */
> diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
> index 7d8b3ceb2af3..b6a9ded9fbb2 100644
> --- a/fs/cifs/inode.c
> +++ b/fs/cifs/inode.c
> @@ -26,6 +26,19 @@
> #include "fs_context.h"
> #include "cifs_ioctl.h"
>
> +/*
> + * Set parameters for the netfs library
> + */
> +static void cifs_set_netfs_context(struct inode *inode)
> +{
> + struct netfs_i_context *ctx = netfs_i_context(inode);
> + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
> +
> + netfs_i_context_init(inode, &cifs_req_ops);
> + ctx->rsize = cifs_sb->ctx->rsize;
> + ctx->wsize = cifs_sb->ctx->wsize;
> +}
> +
> static void cifs_set_ops(struct inode *inode)
> {
> struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
> @@ -209,8 +222,10 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr)
>
> if (fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL)
> inode->i_flags |= S_AUTOMOUNT;
> - if (inode->i_state & I_NEW)
> + if (inode->i_state & I_NEW) {
> + cifs_set_netfs_context(inode);
> cifs_set_ops(inode);
> + }
> return 0;
> }
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index ebbea7526ee2..0d76cffb4e75 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -23,6 +23,7 @@
> #include <linux/uuid.h>
> #include <linux/pagemap.h>
> #include <linux/xattr.h>
> +#include <linux/netfs.h>
> #include "cifsglob.h"
> #include "cifsacl.h"
> #include "cifsproto.h"
> @@ -4185,7 +4186,19 @@ smb2_readv_callback(struct mid_q_entry *mid)
> tcon->tid, tcon->ses->Suid,
> rdata->offset, rdata->got_bytes);
>
> - queue_work(cifsiod_wq, &rdata->work);
> + if (rdata->result == -ENODATA) {
> + /* We may have got an EOF error because fallocate
> + * failed to enlarge the file.
> + */
> + if (rdata->subreq->start < rdata->subreq->rreq->i_size)
> + rdata->result = 0;
> + }
> + if (rdata->result == 0 || rdata->result == -EAGAIN)
> + iov_iter_advance(&rdata->subreq->iter, rdata->got_bytes);
> + netfs_subreq_terminated(rdata->subreq,
> + (rdata->result == 0 || rdata->result == -EAGAIN) ?
> + rdata->got_bytes : rdata->result, false);
> + kref_put(&rdata->refcount, cifs_readdata_release);
> DeleteMidQEntry(mid);
> add_credits(server, &credits, 0);
> }
> diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
> index df13c9b22ca8..1fa242140dc4 100644
> --- a/fs/netfs/read_helper.c
> +++ b/fs/netfs/read_helper.c
> @@ -553,8 +553,13 @@ static void netfs_rreq_assess_dio(struct netfs_read_request *rreq)
> list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
> if (subreq->error || subreq->transferred == 0)
> break;
> - for (i = 0; i < subreq->bv_count; i++)
> + for (i = 0; i < subreq->bv_count; i++) {
> flush_dcache_page(subreq->bv[i].bv_page);
> + // TODO: cifs marks pages in the destination buffer
> + // dirty under some circumstances after a read. Do we
> + // need to do that too?
> + set_page_dirty(subreq->bv[i].bv_page);
> + }
> transferred += subreq->transferred;
> if (subreq->transferred < subreq->len)
> break;
>
>
