From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read 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 Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- include/scsi/scsi_eh.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 include/scsi/scsi_eh.h (limited to 'include/scsi/scsi_eh.h') diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h new file mode 100644 index 000000000..15679be90 --- /dev/null +++ b/include/scsi/scsi_eh.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _SCSI_SCSI_EH_H +#define _SCSI_SCSI_EH_H + +#include + +#include +#include +struct scsi_device; +struct Scsi_Host; + +extern void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, + struct list_head *done_q); +extern void scsi_eh_flush_done_q(struct list_head *done_q); +extern void scsi_report_bus_reset(struct Scsi_Host *, int); +extern void scsi_report_device_reset(struct Scsi_Host *, int, int); +extern int scsi_block_when_processing_errors(struct scsi_device *); +extern bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd, + struct scsi_sense_hdr *sshdr); +extern enum scsi_disposition scsi_check_sense(struct scsi_cmnd *); + +static inline bool scsi_sense_is_deferred(const struct scsi_sense_hdr *sshdr) +{ + return ((sshdr->response_code >= 0x70) && (sshdr->response_code & 1)); +} + +extern bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len, + u64 *info_out); + +extern int scsi_ioctl_reset(struct scsi_device *, int __user *); + +struct scsi_eh_save { + /* saved state */ + int result; + unsigned int resid_len; + int eh_eflags; + enum dma_data_direction data_direction; + unsigned underflow; + unsigned char cmd_len; + unsigned char prot_op; + unsigned char cmnd[32]; + struct scsi_data_buffer sdb; + struct scatterlist sense_sgl; + + /* struct request fields */ +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + struct bio_crypt_ctx *rq_crypt_ctx; + struct blk_crypto_keyslot *rq_crypt_keyslot; +#endif +}; + +extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, + struct scsi_eh_save *ses, unsigned char *cmnd, + int cmnd_size, unsigned sense_bytes); + +extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, + struct scsi_eh_save *ses); + +#endif /* _SCSI_SCSI_EH_H */ -- cgit v1.3.1