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| author | Paulo Alcantara <pc@manguebit.org> | 2026-09-27 18:56:55 -0300 |
|---|---|---|
| committer | Paulo Alcantara <pc@manguebit.org> | 2026-09-30 14:24:16 -0300 |
| commit | 75aa4b4d557114276bb72e19a9bce5cb27b5e4b8 (patch) | |
| tree | c39b1d66d3dec34882dbcc02a073dbe4c786860b /fs | |
| parent | dd05add7b2b6004c5fa3a1f276f56d8668f86b65 (diff) | |
| download | linux-stable-75aa4b4d557114276bb72e19a9bce5cb27b5e4b8.tar.gz linux-stable-75aa4b4d557114276bb72e19a9bce5cb27b5e4b8.zip | |
smb: client: distinguish real EOF from a stale remote_i_size on read
smb2_readv_callback() sets NETFS_SREQ_HIT_EOF whenever a short read
lines up with netfs_read_remote_i_size(inode), the server's EOF as the
client currently believes it. That belief can be stale: after a lease
downgrade and handle reopen, the tracked remote_i_size can sit below
the client's own i_size while an extending write hasn't reached the
server yet. A read in that gap comes back short for a reason that has
nothing to do with the file's real size, but was still marked HIT_EOF,
and netfs reports a short read for it as-is.
Only treat it as real EOF when the position is also at or past the
client's own i_size; otherwise mark it NETFS_SREQ_CLEAR_TAIL instead,
which tells netfs the shortfall is safe to zero-fill rather than
report as a short read.
This is what fsx (generic/363) sees as "short read: 0x0 bytes instead
of 0x<n>" against a Windows server.
Fixes: 1da29f2c39b6 ("netfs, cifs: Fix handling of short DIO read")
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
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/smb/client/smb2pdu.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 3d7ead36d..cfe3c4b4a 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -4796,14 +4796,20 @@ do_retry: rdata->got_bytes); if (rdata->result == -ENODATA) { - __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); rdata->result = 0; + if (rdata->subreq.start + rdata->subreq.transferred >= i_size_read(inode)) + __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); + else + __set_bit(NETFS_SREQ_CLEAR_TAIL, &rdata->subreq.flags); } else { size_t trans = rdata->subreq.transferred + rdata->got_bytes; if (trans < rdata->subreq.len && rdata->subreq.start + trans >= netfs_read_remote_i_size(inode)) { - __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); rdata->result = 0; + if (rdata->subreq.start + trans >= i_size_read(inode)) + __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); + else + __set_bit(NETFS_SREQ_CLEAR_TAIL, &rdata->subreq.flags); } if (rdata->got_bytes) __set_bit(NETFS_SREQ_MADE_PROGRESS, &rdata->subreq.flags); |