Merge tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs client updates from Steve French:
 "The largest subset of this is from David Howells et al: making the
  cifs/smb3 driver pass iov_iters down to the lowest layers, directly to
  the network transport rather than passing lists of pages around,
  helping multiple areas:

   - Pin user pages, thereby fixing the race between concurrent DIO read
     and fork, where the pages containing the DIO read buffer may end up
     belonging to the child process and not the parent - with the result
     that the parent might not see the retrieved data.

   - cifs shouldn't take refs on pages extracted from non-user-backed
     iterators (eg. KVEC). With these changes, cifs will apply the
     appropriate cleanup.

   - Making it easier to transition to using folios in cifs rather than
     pages by dealing with them through BVEC and XARRAY iterators.

   - Allowing cifs to use the new splice function

  The remainder are:

   - fixes for stable, including various fixes for uninitialized memory,
     wrong length field causing mount issue to very old servers,
     important directory lease fixes and reconnect fixes

   - cleanups (unused code removal, change one element array usage, and
     a change form strtobool to kstrtobool, and Kconfig cleanups)

   - SMBDIRECT (RDMA) fixes including iov_iter integration and UAF fixes

   - reconnect fixes

   - multichannel fixes, including improving channel allocation (to
     least used channel)

   - remove the last use of lock_page_killable by moving to
     folio_lock_killable"

* tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: (46 commits)
  update internal module version number for cifs.ko
  cifs: update ip_addr for ses only for primary chan setup
  cifs: use tcon allocation functions even for dummy tcon
  cifs: use the least loaded channel for sending requests
  cifs: DIO to/from KVEC-type iterators should now work
  cifs: Remove unused code
  cifs: Build the RDMA SGE list directly from an iterator
  cifs: Change the I/O paths to use an iterator rather than a page list
  cifs: Add a function to read into an iter from a socket
  cifs: Add some helper functions
  cifs: Add a function to Hash the contents of an iterator
  cifs: Add a function to build an RDMA SGE list from an iterator
  netfs: Add a function to extract an iterator into a scatterlist
  netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator
  cifs: Implement splice_read to pass down ITER_BVEC not ITER_PIPE
  splice: Export filemap/direct_splice_read()
  iov_iter: Add a function to extract a page list from an iterator
  iov_iter: Define flags to qualify page extraction.
  splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE
  splice: Add a func to do a splice from a buffered file without ITER_PIPE
  ...

1 files changed, 39 insertions, 42 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index cd8171a1c9a0..a99883f16d94 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -78,10 +78,6 @@
 #define SMB_ECHO_INTERVAL_MAX 600
 #define SMB_ECHO_INTERVAL_DEFAULT 60
 
-/* dns resolution intervals in seconds */
-#define SMB_DNS_RESOLVE_INTERVAL_MIN     120
-#define SMB_DNS_RESOLVE_INTERVAL_DEFAULT 600
-
 /* smb multichannel query server interfaces interval in seconds */
 #define SMB_INTERFACE_POLL_INTERVAL	600
 
@@ -217,11 +213,9 @@ static inline void cifs_free_open_info(struct cifs_open_info_data *data)
 struct smb_rqst {
 	struct kvec	*rq_iov;	/* array of kvecs */
 	unsigned int	rq_nvec;	/* number of kvecs in array */
-	struct page	**rq_pages;	/* pointer to array of page ptrs */
-	unsigned int	rq_offset;	/* the offset to the 1st page */
-	unsigned int	rq_npages;	/* number pages in array */
-	unsigned int	rq_pagesz;	/* page size to use */
-	unsigned int	rq_tailsz;	/* length of last page */
+	size_t		rq_iter_size;	/* Amount of data in ->rq_iter */
+	struct iov_iter	rq_iter;	/* Data iterator */
+	struct xarray	rq_buffer;	/* Page buffer for encryption */
 };
 
 struct mid_q_entry;
@@ -692,7 +686,6 @@ struct TCP_Server_Info {
 	/* point to the SMBD connection if RDMA is used instead of socket */
 	struct smbd_connection *smbd_conn;
 	struct delayed_work	echo; /* echo ping workqueue job */
-	struct delayed_work	resolve; /* dns resolution workqueue job */
 	char	*smallbuf;	/* pointer to current "small" buffer */
 	char	*bigbuf;	/* pointer to current "big" buffer */
 	/* Total size of this PDU. Only valid from cifs_demultiplex_thread */
@@ -1427,10 +1420,11 @@ struct cifs_aio_ctx {
 	struct cifsFileInfo	*cfile;
 	struct bio_vec		*bv;
 	loff_t			pos;
-	unsigned int		npages;
+	unsigned int		nr_pinned_pages;
 	ssize_t			rc;
 	unsigned int		len;
 	unsigned int		total_len;
+	unsigned int		bv_need_unpin;	/* If ->bv[] needs unpinning */
 	bool			should_dirty;
 	/*
 	 * Indicates if this aio_ctx is for direct_io,
@@ -1448,28 +1442,18 @@ struct cifs_readdata {
 	struct address_space		*mapping;
 	struct cifs_aio_ctx		*ctx;
 	__u64				offset;
+	ssize_t				got_bytes;
 	unsigned int			bytes;
-	unsigned int			got_bytes;
 	pid_t				pid;
 	int				result;
 	struct work_struct		work;
-	int (*read_into_pages)(struct TCP_Server_Info *server,
-				struct cifs_readdata *rdata,
-				unsigned int len);
-	int (*copy_into_pages)(struct TCP_Server_Info *server,
-				struct cifs_readdata *rdata,
-				struct iov_iter *iter);
+	struct iov_iter			iter;
 	struct kvec			iov[2];
 	struct TCP_Server_Info		*server;
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	struct smbd_mr			*mr;
 #endif
-	unsigned int			pagesz;
-	unsigned int			page_offset;
-	unsigned int			tailsz;
 	struct cifs_credits		credits;
-	unsigned int			nr_pages;
-	struct page			**pages;
 };
 
 /* asynchronous write support */
@@ -1481,6 +1465,8 @@ struct cifs_writedata {
 	struct work_struct		work;
 	struct cifsFileInfo		*cfile;
 	struct cifs_aio_ctx		*ctx;
+	struct iov_iter			iter;
+	struct bio_vec			*bv;
 	__u64				offset;
 	pid_t				pid;
 	unsigned int			bytes;
@@ -1489,12 +1475,7 @@ struct cifs_writedata {
 #ifdef CONFIG_CIFS_SMB_DIRECT
 	struct smbd_mr			*mr;
 #endif
-	unsigned int			pagesz;
-	unsigned int			page_offset;
-	unsigned int			tailsz;
 	struct cifs_credits		credits;
-	unsigned int			nr_pages;
-	struct page			**pages;
 };
 
 /*
@@ -2154,15 +2135,21 @@ static inline void move_cifs_info_to_smb2(struct smb2_file_all_info *dst, const
 	dst->FileNameLength = src->FileNameLength;
 }
 
-static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
-					    int num_rqst,
-					    const u8 *sig)
+static inline int cifs_get_num_sgs(const struct smb_rqst *rqst,
+				   int num_rqst,
+				   const u8 *sig)
 {
 	unsigned int len, skip;
 	unsigned int nents = 0;
 	unsigned long addr;
 	int i, j;
 
+	/*
+	 * The first rqst has a transform header where the first 20 bytes are
+	 * not part of the encrypted blob.
+	 */
+	skip = 20;
+
 	/* Assumes the first rqst has a transform header as the first iov.
 	 * I.e.
 	 * rqst[0].rq_iov[0]  is transform header
@@ -2170,14 +2157,22 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
 	 * rqst[1+].rq_iov[0+] data to be encrypted/decrypted
 	 */
 	for (i = 0; i < num_rqst; i++) {
-		/*
-		 * The first rqst has a transform header where the
-		 * first 20 bytes are not part of the encrypted blob.
+		/* We really don't want a mixture of pinned and unpinned pages
+		 * in the sglist.  It's hard to keep track of which is what.
+		 * Instead, we convert to a BVEC-type iterator higher up.
 		 */
+		if (WARN_ON_ONCE(user_backed_iter(&rqst[i].rq_iter)))
+			return -EIO;
+
+		/* We also don't want to have any extra refs or pins to clean
+		 * up in the sglist.
+		 */
+		if (WARN_ON_ONCE(iov_iter_extract_will_pin(&rqst[i].rq_iter)))
+			return -EIO;
+
 		for (j = 0; j < rqst[i].rq_nvec; j++) {
 			struct kvec *iov = &rqst[i].rq_iov[j];
 
-			skip = (i == 0) && (j == 0) ? 20 : 0;
 			addr = (unsigned long)iov->iov_base + skip;
 			if (unlikely(is_vmalloc_addr((void *)addr))) {
 				len = iov->iov_len - skip;
@@ -2186,8 +2181,9 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
 			} else {
 				nents++;
 			}
+			skip = 0;
 		}
-		nents += rqst[i].rq_npages;
+		nents += iov_iter_npages(&rqst[i].rq_iter, INT_MAX);
 	}
 	nents += DIV_ROUND_UP(offset_in_page(sig) + SMB2_SIGNATURE_SIZE, PAGE_SIZE);
 	return nents;
@@ -2196,9 +2192,9 @@ static inline unsigned int cifs_get_num_sgs(const struct smb_rqst *rqst,
 /* We can not use the normal sg_set_buf() as we will sometimes pass a
  * stack object as buf.
  */
-static inline struct scatterlist *cifs_sg_set_buf(struct scatterlist *sg,
-						  const void *buf,
-						  unsigned int buflen)
+static inline void cifs_sg_set_buf(struct sg_table *sgtable,
+				   const void *buf,
+				   unsigned int buflen)
 {
 	unsigned long addr = (unsigned long)buf;
 	unsigned int off = offset_in_page(addr);
@@ -2208,16 +2204,17 @@ static inline struct scatterlist *cifs_sg_set_buf(struct scatterlist *sg,
 		do {
 			unsigned int len = min_t(unsigned int, buflen, PAGE_SIZE - off);
 
-			sg_set_page(sg++, vmalloc_to_page((void *)addr), len, off);
+			sg_set_page(&sgtable->sgl[sgtable->nents++],
+				    vmalloc_to_page((void *)addr), len, off);
 
 			off = 0;
 			addr += PAGE_SIZE;
 			buflen -= len;
 		} while (buflen);
 	} else {
-		sg_set_page(sg++, virt_to_page(addr), buflen, off);
+		sg_set_page(&sgtable->sgl[sgtable->nents++],
+			    virt_to_page(addr), buflen, off);
 	}
-	return sg;
 }
 
 #endif	/* _CIFS_GLOB_H */