Merge tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:

 - Relax assertions on failure to encode file handles

   The ->encode_fh() method can fail for various reasons. None of them
   warrant a WARN_ON().

 - Fix overlayfs file handle encoding by allowing encoding an fid from
   an inode without an alias

 - Make sure fuse_dir_open() handles FOPEN_KEEP_CACHE. If it's not
   specified fuse needs to invaludate the directory inode page cache

 - Fix qnx6 so it builds with gcc-15

 - Various fixes for netfslib and ceph and nfs filesystems:
     - Ignore silly rename files from afs and nfs when building header
       archives
     - Fix read result collection in netfslib with multiple subrequests
     - Handle ENOMEM for netfslib buffered reads
     - Fix oops in nfs_netfs_init_request()
     - Parse the secctx command immediately in cachefiles
     - Remove a redundant smp_rmb() in netfslib
     - Handle recursion in read retry in netfslib
     - Fix clearing of folio_queue
     - Fix missing cancellation of copy-to_cache when the cache for a
       file is temporarly disabled in netfslib

 - Sanity check the hfs root record

 - Fix zero padding data issues in concurrent write scenarios

 - Fix is_mnt_ns_file() after converting nsfs to path_from_stashed()

 - Fix missing declaration of init_files

 - Increase I/O priority when writing revoke records in jbd2

 - Flush filesystem device before updating tail sequence in jbd2

* tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
  ovl: support encoding fid from inode with no alias
  ovl: pass realinode to ovl_encode_real_fh() instead of realdentry
  fuse: respect FOPEN_KEEP_CACHE on opendir
  netfs: Fix is-caching check in read-retry
  netfs: Fix the (non-)cancellation of copy when cache is temporarily disabled
  netfs: Fix ceph copy to cache on write-begin
  netfs: Work around recursion by abandoning retry if nothing read
  netfs: Fix missing barriers by using clear_and_wake_up_bit()
  netfs: Remove redundant use of smp_rmb()
  cachefiles: Parse the "secctx" immediately
  nfs: Fix oops in nfs_netfs_init_request() when copying to cache
  netfs: Fix enomem handling in buffered reads
  netfs: Fix non-contiguous donation between completed reads
  kheaders: Ignore silly-rename files
  fs: relax assertions on failure to encode file handles
  fs: fix missing declaration of init_files
  fs: fix is_mnt_ns_file()
  iomap: fix zero padding data issue in concurrent append writes
  iomap: pass byte granular end position to iomap_add_to_ioend
  jbd2: flush filesystem device before updating tail sequence
  ...

1 files changed, 57 insertions, 9 deletions

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 955f19e27e47..54dc27d92781 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1774,7 +1774,8 @@ static bool iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t pos)
  */
 static int iomap_add_to_ioend(struct iomap_writepage_ctx *wpc,
 		struct writeback_control *wbc, struct folio *folio,
-		struct inode *inode, loff_t pos, unsigned len)
+		struct inode *inode, loff_t pos, loff_t end_pos,
+		unsigned len)
 {
 	struct iomap_folio_state *ifs = folio->private;
 	size_t poff = offset_in_folio(folio, pos);
@@ -1793,15 +1794,60 @@ new_ioend:
 
 	if (ifs)
 		atomic_add(len, &ifs->write_bytes_pending);
+
+	/*
+	 * Clamp io_offset and io_size to the incore EOF so that ondisk
+	 * file size updates in the ioend completion are byte-accurate.
+	 * This avoids recovering files with zeroed tail regions when
+	 * writeback races with appending writes:
+	 *
+	 *    Thread 1:                  Thread 2:
+	 *    ------------               -----------
+	 *    write [A, A+B]
+	 *    update inode size to A+B
+	 *    submit I/O [A, A+BS]
+	 *                               write [A+B, A+B+C]
+	 *                               update inode size to A+B+C
+	 *    <I/O completes, updates disk size to min(A+B+C, A+BS)>
+	 *    <power failure>
+	 *
+	 *  After reboot:
+	 *    1) with A+B+C < A+BS, the file has zero padding in range
+	 *       [A+B, A+B+C]
+	 *
+	 *    |<     Block Size (BS)   >|
+	 *    |DDDDDDDDDDDD0000000000000|
+	 *    ^           ^        ^
+	 *    A          A+B     A+B+C
+	 *                       (EOF)
+	 *
+	 *    2) with A+B+C > A+BS, the file has zero padding in range
+	 *       [A+B, A+BS]
+	 *
+	 *    |<     Block Size (BS)   >|<     Block Size (BS)    >|
+	 *    |DDDDDDDDDDDD0000000000000|00000000000000000000000000|
+	 *    ^           ^             ^           ^
+	 *    A          A+B           A+BS       A+B+C
+	 *                             (EOF)
+	 *
+	 *    D = Valid Data
+	 *    0 = Zero Padding
+	 *
+	 * Note that this defeats the ability to chain the ioends of
+	 * appending writes.
+	 */
 	wpc->ioend->io_size += len;
+	if (wpc->ioend->io_offset + wpc->ioend->io_size > end_pos)
+		wpc->ioend->io_size = end_pos - wpc->ioend->io_offset;
+
 	wbc_account_cgroup_owner(wbc, folio, len);
 	return 0;
 }
 
 static int iomap_writepage_map_blocks(struct iomap_writepage_ctx *wpc,
 		struct writeback_control *wbc, struct folio *folio,
-		struct inode *inode, u64 pos, unsigned dirty_len,
-		unsigned *count)
+		struct inode *inode, u64 pos, u64 end_pos,
+		unsigned dirty_len, unsigned *count)
 {
 	int error;
 
@@ -1826,7 +1872,7 @@ static int iomap_writepage_map_blocks(struct iomap_writepage_ctx *wpc,
 			break;
 		default:
 			error = iomap_add_to_ioend(wpc, wbc, folio, inode, pos,
-					map_len);
+					end_pos, map_len);
 			if (!error)
 				(*count)++;
 			break;
@@ -1897,11 +1943,11 @@ static bool iomap_writepage_handle_eof(struct folio *folio, struct inode *inode,
 		 *    remaining memory is zeroed when mapped, and writes to that
 		 *    region are not written out to the file.
 		 *
-		 * Also adjust the writeback range to skip all blocks entirely
-		 * beyond i_size.
+		 * Also adjust the end_pos to the end of file and skip writeback
+		 * for all blocks entirely beyond i_size.
 		 */
 		folio_zero_segment(folio, poff, folio_size(folio));
-		*end_pos = round_up(isize, i_blocksize(inode));
+		*end_pos = isize;
 	}
 
 	return true;
@@ -1914,6 +1960,7 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 	struct inode *inode = folio->mapping->host;
 	u64 pos = folio_pos(folio);
 	u64 end_pos = pos + folio_size(folio);
+	u64 end_aligned = 0;
 	unsigned count = 0;
 	int error = 0;
 	u32 rlen;
@@ -1955,9 +2002,10 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 	/*
 	 * Walk through the folio to find dirty areas to write back.
 	 */
-	while ((rlen = iomap_find_dirty_range(folio, &pos, end_pos))) {
+	end_aligned = round_up(end_pos, i_blocksize(inode));
+	while ((rlen = iomap_find_dirty_range(folio, &pos, end_aligned))) {
 		error = iomap_writepage_map_blocks(wpc, wbc, folio, inode,
-				pos, rlen, &count);
+				pos, end_pos, rlen, &count);
 		if (error)
 			break;
 		pos += rlen;