linux/fs/netfs
David Howells 1da29f2c39 netfs, cifs: Fix handling of short DIO read
Short DIO reads, particularly in relation to cifs, are not being handled
correctly by cifs and netfslib.  This can be tested by doing a DIO read of
a file where the size of read is larger than the size of the file.  When it
crosses the EOF, it gets a short read and this gets retried, and in the
case of cifs, the retry read fails, with the failure being translated to
ENODATA.

Fix this by the following means:

 (1) Add a flag, NETFS_SREQ_HIT_EOF, for the filesystem to set when it
     detects that the read did hit the EOF.

 (2) Make the netfslib read assessment stop processing subrequests when it
     encounters one with that flag set.

 (3) Return rreq->transferred, the accumulated contiguous amount read to
     that point, to userspace for a DIO read.

 (4) Make cifs set the flag and clear the error if the read RPC returned
     ENODATA.

 (5) Make cifs set the flag and clear the error if a short read occurred
     without error and the read-to file position is now at the remote inode
     size.

Fixes: 69c3c023af ("cifs: Implement netfslib hooks")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-08-28 07:47:36 -05:00
..
buffered_read.c netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags 2024-08-12 22:03:27 +02:00
buffered_write.c netfs: Fault in smaller chunks for non-large folio mappings 2024-08-12 22:03:25 +02:00
direct_read.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
direct_write.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
fscache_cache.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
fscache_cookie.c fs/netfs/fscache_cookie: add missing "n_accesses" check 2024-08-12 22:03:26 +02:00
fscache_internal.h netfs, fscache: Combine fscache with netfs 2023-12-24 15:08:46 +00:00
fscache_io.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
fscache_main.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
fscache_proc.c netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs" 2024-01-04 13:15:32 +00:00
fscache_stats.c netfs: Fix interaction between write-streaming and cachefiles culling 2024-01-05 15:42:25 +00:00
fscache_volume.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
internal.h netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
io.c netfs, cifs: Fix handling of short DIO read 2024-08-28 07:47:36 -05:00
iterator.c netfs: Add func to calculate pagecount/size-limited span of an iterator 2023-12-28 09:45:18 +00:00
Kconfig netfs: clean up after renaming FSCACHE_DEBUG config 2024-08-12 22:03:26 +02:00
locking.c netfs: Implement unbuffered/DIO vs buffered I/O locking 2023-12-24 15:08:52 +00:00
main.c netfs: Revert "netfs: Switch debug logging to pr_debug()" 2024-07-24 10:15:37 +02:00
Makefile netfs: Cut over to using new writeback code 2024-05-01 18:07:37 +01:00
misc.c netfs: Fix trimming of streaming-write folios in netfs_inval_folio() 2024-08-24 16:09:16 +02:00
objects.c netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags 2024-08-12 22:03:27 +02:00
stats.c netfs: Add some write-side stats and clean up some stat names 2024-05-01 18:07:36 +01:00
write_collect.c netfs: Fix interaction of streaming writes with zero-point tracker 2024-08-24 16:09:17 +02:00
write_issue.c netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags 2024-08-12 22:03:27 +02:00