smb: client: fix generic/694 due to wrong ->i_blocks

When updating ->i_size, make sure to always update ->i_blocks as well
until we query new allocation size from the server.

generic/694 was failing because smb3_simple_falloc() was missing the
update of ->i_blocks after calling cifs_setsize().  So, fix this by
updating ->i_blocks directly in cifs_setsize(), so all places that
call it doesn't need to worry about updating ->i_blocks later.

Reported-by: Shyam Prasad N <sprasad@microsoft.com>
Closes: https://lore.kernel.org/r/CANT5p=rqgRwaADB=b_PhJkqXjtfq3SFv41SSTXSVEHnuh871pA@mail.gmail.com
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: pcacjr

fs/smb/client/cifsglob.h

@@ -2386,4 +2386,10 @@ static inline int cifs_open_create_options(unsigned int oflags, int opts)
 	return opts;
 }
 
+/*
+ * The number of blocks is not related to (i_size / i_blksize), but instead
+ * 512 byte (2**9) size is required for calculating num blocks.
+ */
+#define CIFS_INO_BLOCKS(size) DIV_ROUND_UP_ULL((u64)(size), 512)
+
 #endif	/* _CIFS_GLOB_H */

fs/smb/client/file.c

@@ -993,7 +993,6 @@ static int cifs_do_truncate(const unsigned int xid, struct dentry *dentry)
 		if (!rc) {
 			netfs_resize_file(&cinode->netfs, 0, true);
 			cifs_setsize(inode, 0);
-			inode->i_blocks = 0;
 		}
 	}
 	if (cfile)

fs/smb/client/inode.c

@@ -219,13 +219,7 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr,
 	 */
 	if (is_size_safe_to_change(cifs_i, fattr->cf_eof, from_readdir)) {
 		i_size_write(inode, fattr->cf_eof);
-
-		/*
-		 * i_blocks is not related to (i_size / i_blksize),
-		 * but instead 512 byte (2**9) size is required for
-		 * calculating num blocks.
-		 */
-		inode->i_blocks = (512 - 1 + fattr->cf_bytes) >> 9;
+		inode->i_blocks = CIFS_INO_BLOCKS(fattr->cf_bytes);
 	}
 
 	if (S_ISLNK(fattr->cf_mode) && fattr->cf_symlink_target) {
@@ -3015,6 +3009,11 @@ void cifs_setsize(struct inode *inode, loff_t offset)
 {
 	spin_lock(&inode->i_lock);
 	i_size_write(inode, offset);
+	/*
+	 * Until we can query the server for actual allocation size,
+	 * this is best estimate we have for blocks allocated for a file.
+	 */
+	inode->i_blocks = CIFS_INO_BLOCKS(offset);
 	spin_unlock(&inode->i_lock);
 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 	truncate_pagecache(inode, offset);
@@ -3087,14 +3086,6 @@ int cifs_file_set_size(const unsigned int xid, struct dentry *dentry,
 	if (rc == 0) {
 		netfs_resize_file(&cifsInode->netfs, size, true);
 		cifs_setsize(inode, size);
-		/*
-		 * i_blocks is not related to (i_size / i_blksize), but instead
-		 * 512 byte (2**9) size is required for calculating num blocks.
-		 * Until we can query the server for actual allocation size,
-		 * this is best estimate we have for blocks allocated for a file
-		 * Number of blocks must be rounded up so size 1 is not 0 blocks
-		 */
-		inode->i_blocks = (512 - 1 + size) >> 9;
 	}
 
 	return rc;

fs/smb/client/smb2ops.c

@@ -1497,6 +1497,7 @@ smb2_close_getattr(const unsigned int xid, struct cifs_tcon *tcon,
 {
 	struct smb2_file_network_open_info file_inf;
 	struct inode *inode;
+	u64 asize;
 	int rc;
 
 	rc = __SMB2_close(xid, tcon, cfile->fid.persistent_fid,
@@ -1520,14 +1521,9 @@ smb2_close_getattr(const unsigned int xid, struct cifs_tcon *tcon,
 		inode_set_atime_to_ts(inode,
 				      cifs_NTtimeToUnix(file_inf.LastAccessTime));
 
-	/*
-	 * i_blocks is not related to (i_size / i_blksize),
-	 * but instead 512 byte (2**9) size is required for
-	 * calculating num blocks.
-	 */
-	if (le64_to_cpu(file_inf.AllocationSize) > 4096)
-		inode->i_blocks =
-			(512 - 1 + le64_to_cpu(file_inf.AllocationSize)) >> 9;
+	asize = le64_to_cpu(file_inf.AllocationSize);
+	if (asize > 4096)
+		inode->i_blocks = CIFS_INO_BLOCKS(asize);
 
 	/* End of file and Attributes should not have to be updated on close */
 	spin_unlock(&inode->i_lock);
@@ -2204,14 +2200,6 @@ smb2_duplicate_extents(const unsigned int xid,
 		rc = smb2_set_file_size(xid, tcon, trgtfile, dest_off + len, false);
 		if (rc)
 			goto duplicate_extents_out;
-
-		/*
-		 * Although also could set plausible allocation size (i_blocks)
-		 * here in addition to setting the file size, in reflink
-		 * it is likely that the target file is sparse. Its allocation
-		 * size will be queried on next revalidate, but it is important
-		 * to make sure that file's cached size is updated immediately
-		 */
 		netfs_resize_file(netfs_inode(inode), dest_off + len, true);
 		cifs_setsize(inode, dest_off + len);
 	}