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path: root/fs/smb/client/cifsglob.h
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11 dayssmb: client: split cifsFileInfo bitfields to avoid shared-byte RMW racesFrank Sorenson
The invalidHandle, swapfile, oplock_break_cancelled, offload, and status_file_deleted fields are stored in the same bitfield byte in struct cifsFileInfo, but are updated in different code paths that may run simultaneously, and are protected by different locks. Since bitfield assignments generate byte-level read-modify-write operations, a modification to one flag can overwrite a concurrent modification to another flag. To avoid these races, convert these flags from a bitfield to separate bool fields. Closes: https://lore.kernel.org/r/7689764e-c0f6-4016-9557-b54cf4a3de4e@redhat.com Fixes: 3bc303c254335 ("cifs: convert oplock breaks to use slow_work facility (try #4)") Fixes: 4e8aea30f7751 ("smb3: enable swap on SMB3 mounts") Fixes: ffceb7640cbfe ("smb: client: do not defer close open handles to deleted files") Fixes: 173217bd73365 ("smb3: retrying on failed server close") Signed-off-by: Frank Sorenson <sorenson@redhat.com> Cc: stable@vger.kernel.org Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
11 daysnetfs: zero the tail of a short DIO/unbuffered readgraftedPaulo Alcantara
The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org