Remove fixed 16 sg_request object array and replace with an active
rq_list plus a request free list. Add finer grained spin lock to
sg_request and do a major rework on locking. sg_request objects now
are only de-allocated when the owning file descriptor is closed.
This simplifies locking issues.
Signed-off-by: Douglas Gilbert <dgilb...@interlog.com>
---
This patch is big and complex. Towards the end the diff program
completely loses the plot. Better to use difftool on a two pane
window, or simply view the before sg.c and the after sg.c .
The requirement to keep the patch small enough to be reviewable
but at the same time both compilable and buildable (i.e. no
undefines when kernel is built) are in conflict, especially when
the changes touch almost all functions in a driver. IMO you
should be able to mark a patch (in the middle of a patchset)
as "non compilable".
drivers/scsi/sg.c | 1305 ++++++++++++++++++++++++++++-----------------
1 file changed, 805 insertions(+), 500 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index a76395f16fb1..5fbdb0f40739 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -141,46 +141,58 @@ struct sg_scatter_hold { /* holding area for scsi
scatter gather info */
struct sg_device; /* forward declarations */
struct sg_fd;
-struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
- struct list_head entry; /* list entry */
- struct sg_fd *parentfp; /* NULL -> not in use */
+/*
+ * For any file descriptor: at any time a sg_request object must be a member
+ * of sg_fd::rq_list or sg_fd::rq_free_list. The only exception is within a
+ * rq_list_lock write lock when it is moving between those two lists.
+ */
+
+struct sg_request { /* active SCSI command or inactive on free list (fl) */
+ struct list_head rq_entry; /* member of rq_list (active cmd) */
+ struct list_head free_entry; /* member of rq_free_list */
+ spinlock_t rq_entry_lck;
struct sg_scatter_hold data; /* hold buffer, perhaps scatter list */
union {
struct sg_io_hdr header; /* see <scsi/sg.h> */
- struct sg_io_v4 hdr_v4; /* see <uapi/linux/bsg.h> */
+ struct sg_v4_hold v4_hold;/* related to <uapi/linux/bsg.h> */
};
- u8 sense_b[SCSI_SENSE_BUFFERSIZE];
- bool hdr_v4_active; /* selector for anonymous union above */
- bool res_used; /* true -> use reserve buffer, false -> don't */
+ ktime_t start_ts; /* used when sg_fd::time_in_ns is true */
+ enum sg_rq_state rq_state;/* tracks lifetime of each request */
+ bool v4_active; /* selector for autonomous union above */
bool orphan; /* true -> drop on sight, false -> normal */
- bool sg_io_owned; /* true -> packet belongs to SG_IO */
- /* done protected by rq_list_lock */
- char done; /* 0->before bh, 1->before read, 2->read */
+ bool sync_invoc;/* true -> synchronous (e.g. from ioctl(SG_IO)) */
+ u8 sense_b[SCSI_SENSE_BUFFERSIZE];
+ struct sg_fd *parentfp; /* pointer to owning fd, even when on fl */
+ struct sg_scatter_hold *d2p; /* optional 2nd data buffer for bidi */
struct request *rq;
struct bio *bio;
- struct execute_work ew;
+ struct execute_work ew_orph; /* harvest orphan request */
};
-struct sg_fd { /* holds the state of a file descriptor */
- struct list_head sfd_siblings; /* protected by device's sfd_lock */
+struct sg_fd { /* holds the state of a file descriptor */
+ struct list_head sfd_entry; /* member sg_device::sfds list */
struct sg_device *parentdp; /* owning device */
wait_queue_head_t read_wait; /* queue read until command done */
- rwlock_t rq_list_lock; /* protect access to list in req_arr */
struct mutex f_mutex; /* protect against changes in this fd */
+ rwlock_t rq_list_lock; /* protect access to sg_request lists */
+ struct list_head rq_list; /* head of inflight sg_request list */
+ struct list_head rq_free_list; /* head of sg_request free list */
int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
- struct sg_scatter_hold reserve; /* one held for this file descriptor */
- struct list_head rq_list; /* head of request list */
- struct fasync_struct *async_qp; /* used by asynchronous notification */
- struct sg_request req_arr[SG_MAX_QUEUE];/* used as singly-linked list */
+ int rem_sgat_thresh; /* > this, request's sgat cleared after use */
+ int tot_fd_thresh; /* E2BIG if sum_of(dlen) > this, 0: ignore */
+ atomic_t sum_fd_dlens; /* when tot_fd_thresh>0 this is sum_of(dlen) */
bool force_packid; /* true -> pack_id input to read() */
bool cmd_q; /* true -> allow command queuing, false -> don't */
- u8 next_cmd_len; /* 0: automatic, >0: use on next write() */
bool keep_orphan;/* false -> drop (def), true -> keep for read() */
bool mmap_called; /* false -> mmap() never called on this fd */
- bool res_in_use; /* true -> 'reserve' array in use */
+ bool sse_seen; /* SG_SET_EXTENDED ioctl seen */
+ bool time_in_ns; /* report times in nanoseconds */
+ u8 next_cmd_len; /* 0: automatic, >0: use on next write() */
+ struct sg_request *reserve_srp; /* allocate on open(), starts on fl */
+ struct fasync_struct *async_qp; /* used by asynchronous notification */
struct kref f_ref;
- struct execute_work ew;
+ struct execute_work ew; /* harvest all active and free list requests */
};
struct sg_device { /* holds the state of each scsi generic device */
@@ -189,8 +201,8 @@ struct sg_device { /* holds the state of each scsi generic
device */
struct mutex open_rel_lock; /* held when in open() or release() */
int sg_tablesize; /* adapter's max scatter-gather table size */
u32 index; /* device index number */
- struct list_head sfds;
- rwlock_t sfd_lock; /* protect access to sfd list */
+ struct list_head sfds; /* head of sg_fd::sfd_entry list */
+ rwlock_t sfd_lock; /* protect access to sfds list */
atomic_t detaching; /* 0->device usable, 1->device detaching */
bool exclude; /* 1->open(O_EXCL) succeeded and is active */
int open_cnt; /* count of opens (perhaps < num(sfds) ) */
@@ -203,36 +215,37 @@ struct sg_device { /* holds the state of each scsi
generic device */
/* tasklet or soft irq callback */
static void sg_rq_end_io(struct request *rq, blk_status_t status);
static int sg_start_req(struct sg_request *srp, u8 *cmd);
-static int sg_finish_rem_req(struct sg_request *srp);
-static int sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
- int buff_size);
+static void sg_finish_scsi_blk_rq(struct sg_request *srp);
+static int sg_mk_sgat_dlen(struct sg_request *srp, struct sg_fd *sfp,
+ int dlen);
static ssize_t sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
struct sg_request *srp);
-static ssize_t sg_new_write(struct sg_fd *sfp, struct file *file,
- const char __user *buf, size_t count, int blocking,
- int read_only, int sg_io_owned,
- struct sg_request **o_srp);
-static int sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
- u8 *cmnd, int timeout, int blocking);
+static ssize_t sg_v3_write(struct sg_fd *sfp, struct file *file,
+ const char __user *buf, size_t count,
+ bool read_only, bool sync,
+ struct sg_request **o_srp);
+static struct sg_request *sg_common_write(struct sg_fd *sfp,
+ const struct sg_io_hdr *hp,
+ struct sg_io_v4 *h4p, u8 *cmnd,
+ bool sync, int timeout);
static int sg_read_oxfer(struct sg_request *srp, char __user *outp,
- int num_read_xfer);
-static void sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp);
-static void sg_build_reserve(struct sg_fd *sfp, int req_size);
-static void sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp,
- int size);
-static void sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp);
+ int num_xfer);
+static void sg_remove_sgat(struct sg_request *srp);
static struct sg_fd *sg_add_sfp(struct sg_device *sdp);
static void sg_remove_sfp(struct kref *);
static struct sg_request *sg_get_rq_pack_id(struct sg_fd *sfp, int pack_id);
-static struct sg_request *sg_add_request(struct sg_fd *sfp);
-static int sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
-static struct sg_device *sg_get_dev(int dev);
+static struct sg_request *sg_add_request(struct sg_fd *sfp, int dxfr_len,
+ bool sync);
+static void sg_remove_request(struct sg_fd *sfp, struct sg_request *srp);
+static struct sg_device *sg_get_dev(int min_dev);
static void sg_device_destroy(struct kref *kref);
-#define SZ_SG_HEADER sizeof(struct sg_header)
-#define SZ_SG_IO_HDR sizeof(struct sg_io_hdr)
+#define SZ_SG_HEADER sizeof(struct sg_header) /* v1 and v2 header */
+#define SZ_SG_IO_HDR sizeof(struct sg_io_hdr) /* v3 header */
+#define SZ_SG_IO_V4 sizeof(struct sg_io_v4) /* v4 header (in bsg.h) */
/* #define SZ_SG_IOVEC sizeof(struct sg_iovec) synonym for 'struct iovec' */
#define SZ_SG_REQ_INFO sizeof(struct sg_req_info)
+#define SZ_SG_EXTENDED_INFO sizeof(struct sg_extended_info)
/*
* Kernel needs to be built with CONFIG_SCSI_LOGGING to see log messages.
@@ -297,7 +310,8 @@ sg_allow_access(struct file *filp, u8 *cmd)
}
static int
-open_wait(struct sg_device *sdp, int flags)
+wait_open_event(struct sg_device *sdp, int flags)
+ __must_hold(&sdp->open_rel_lock)
{
int retval = 0;
@@ -386,7 +400,7 @@ sg_open(struct inode *inode, struct file *filp)
}
}
} else {
- retval = open_wait(sdp, flags);
+ retval = wait_open_event(sdp, flags);
if (retval) /* -ERESTARTSYS or -ENODEV */
goto error_mutex_locked;
}
@@ -623,7 +637,7 @@ sg_read(struct file *filp, char __user *buf, size_t count,
loff_t * ppos)
}
} else
count = (ohdr->result == 0) ? 0 : -EIO;
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
retval = count;
free_old_hdr:
@@ -635,13 +649,13 @@ static ssize_t
sg_new_read(struct sg_fd *sfp, char __user *buf, size_t count,
struct sg_request *srp)
{
- int err = 0, err2;
+ int err = 0;
int len;
struct sg_io_hdr *hp = &srp->header;
if (count < SZ_SG_IO_HDR) {
err = -EINVAL;
- goto err_out;
+ goto out;
}
hp->sb_len_wr = 0;
if ((hp->mx_sb_len > 0) && hp->sbp) {
@@ -654,7 +668,7 @@ sg_new_read(struct sg_fd *sfp, char __user *buf, size_t
count,
len = (len > sb_len) ? sb_len : len;
if (copy_to_user(hp->sbp, srp->sense_b, len)) {
err = -EFAULT;
- goto err_out;
+ goto out;
}
hp->sb_len_wr = len;
}
@@ -663,27 +677,28 @@ sg_new_read(struct sg_fd *sfp, char __user *buf, size_t
count,
hp->info |= SG_INFO_CHECK;
if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
err = -EFAULT;
- goto err_out;
+ goto out;
}
-err_out:
- err2 = sg_finish_rem_req(srp);
+ if (atomic_read(&sfp->parentdp->detaching))/* okay but on thin ice */
+ hp->info |= SG_INFO_DEVICE_DETACHING;
+out:
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
- return err ? : err2 ? : count;
+ return err ? err : count;
}
static ssize_t
sg_write(struct file *filp, const char __user *buf, size_t count, loff_t *
ppos)
{
- int mxsize, cmd_size, k;
- int input_size, blocking;
+ int mxsize, cmd_size, input_size, retval;
u8 opcode;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
- struct sg_io_hdr *hp;
u8 cmnd[SG_MAX_CDB_SIZE];
- int retval;
struct sg_header ohdr;
+ struct sg_io_hdr v3hdr;
+ struct sg_io_hdr *hp = &v3hdr;
retval = sg_check_file_access(filp, __func__);
if (retval)
@@ -710,17 +725,11 @@ sg_write(struct file *filp, const char __user *buf,
size_t count, loff_t * ppos)
return -EIO;
if (__copy_from_user(&ohdr, buf, SZ_SG_HEADER))
return -EFAULT;
- blocking = !(filp->f_flags & O_NONBLOCK);
if (ohdr.reply_len < 0)
- return sg_new_write(sfp, filp, buf, count,
- blocking, 0, 0, NULL);
+ return sg_v3_write(sfp, filp, buf, count, false, false, NULL);
if (count < (SZ_SG_HEADER + 6))
return -EIO; /* minimum scsi command length is 6 bytes */
- if (!(srp = sg_add_request(sfp))) {
- SG_LOG(1, sdp, "%s: queue full\n", __func__);
- return -EDOM;
- }
buf += SZ_SG_HEADER;
__get_user(opcode, buf);
mutex_lock(&sfp->f_mutex);
@@ -739,12 +748,10 @@ sg_write(struct file *filp, const char __user *buf,
size_t count, loff_t * ppos)
mxsize = (input_size > ohdr.reply_len) ? input_size : ohdr.reply_len;
mxsize -= SZ_SG_HEADER;
input_size -= SZ_SG_HEADER;
- if (input_size < 0) {
- sg_remove_request(sfp, srp);
+ if (input_size < 0)
return -EIO; /* Insufficient bytes passed for this command. */
- }
- hp = &srp->header;
- hp->interface_id = '\0'; /* indicator of old interface tunnelled */
+ memset(hp, 0, sizeof(*hp));
+ hp->interface_id = '\0';/* indicate old interface tunnelled */
hp->cmd_len = (u8)cmd_size;
hp->iovec_count = 0;
hp->mx_sb_len = 0;
@@ -762,111 +769,95 @@ sg_write(struct file *filp, const char __user *buf,
size_t count, loff_t * ppos)
hp->dxferp = NULL;
hp->sbp = NULL;
hp->timeout = ohdr.reply_len; /* structure abuse ... */
- hp->flags = input_size; /* structure abuse ... */
+ hp->flags = input_size; /* structure abuse ... */
hp->pack_id = ohdr.pack_id;
hp->usr_ptr = NULL;
if (__copy_from_user(cmnd, buf, cmd_size))
return -EFAULT;
/*
* SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
- * but is is possible that the app intended SG_DXFER_TO_DEV, because
there
- * is a non-zero input_size, so emit a warning.
+ * but is is possible that the app intended SG_DXFER_TO_DEV, because
+ * there is a non-zero input_size, so emit a warning.
*/
if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
printk_ratelimited(KERN_WARNING
- "sg_write: data in/out %d/%d bytes "
- "for SCSI command 0x%x-- guessing "
- "data in;\n program %s not setting "
- "count and/or reply_len properly\n",
- ohdr.reply_len - (int)SZ_SG_HEADER,
- input_size, (unsigned int)cmnd[0],
- current->comm);
- }
- k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
- return (k < 0) ? k : count;
+ "%s: data in/out %d/%d bytes for SCSI command 0x%x--
guessing data in;\n"
+ " program %s not setting count and/or reply_len
properly\n",
+ __func__, ohdr.reply_len - (int)SZ_SG_HEADER,
+ input_size, (unsigned int)cmnd[0], current->comm);
+ }
+ srp = sg_common_write(sfp, hp, NULL, cmnd, false, sfp->timeout);
+ return (IS_ERR(srp)) ? PTR_ERR(srp) : count;
}
static ssize_t
-sg_new_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
- size_t count, int blocking, int read_only, int sg_io_owned,
- struct sg_request **o_srp)
+sg_v3_write(struct sg_fd *sfp, struct file *file, const char __user *buf,
+ size_t count, bool read_only, bool sync,
+ struct sg_request **o_srp)
{
- int k;
- struct sg_request *srp;
- struct sg_io_hdr *hp;
- u8 cmnd[SG_MAX_CDB_SIZE];
+ struct sg_io_hdr v3hdr;
int timeout;
unsigned long ul_timeout;
+ struct sg_io_hdr *hp = &v3hdr;
+ struct sg_request *srp;
+ u8 cmnd[SG_MAX_CDB_SIZE];
if (count < SZ_SG_IO_HDR)
return -EINVAL;
if (!access_ok(VERIFY_READ, buf, count))
- return -EFAULT; /* protects following copy_from_user()s +
get_user()s */
-
- sfp->cmd_q = true; /* when sg_io_hdr seen, set command queuing on */
- if (!(srp = sg_add_request(sfp))) {
- SG_LOG(1, sfp->parentdp, "%s: queue full\n", __func__);
- return -EDOM;
- }
- srp->sg_io_owned = sg_io_owned;
- hp = &srp->header;
- if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
- sg_remove_request(sfp, srp);
return -EFAULT;
- }
- if (hp->interface_id != 'S') {
- sg_remove_request(sfp, srp);
+ if (__copy_from_user(hp, buf, SZ_SG_IO_HDR))
+ return -EFAULT;
+ if (hp->interface_id == 'Q')
+ return -EOPNOTSUPP; /* placeholder for sgv4 interface */
+ else if (hp->interface_id != 'S')
return -ENOSYS;
- }
if (hp->flags & SG_FLAG_MMAP_IO) {
- if (hp->dxfer_len > sfp->reserve.dlen) {
- sg_remove_request(sfp, srp);
- return -ENOMEM; /* MMAP_IO size must fit in reserve
buffer */
- }
- if (hp->flags & SG_FLAG_DIRECT_IO) {
- sg_remove_request(sfp, srp);
- return -EINVAL; /* either MMAP_IO or DIRECT_IO (not
both) */
- }
- if (sfp->res_in_use) {
- sg_remove_request(sfp, srp);
- return -EBUSY; /* reserve buffer already being used */
- }
+ if (!list_empty(&sfp->rq_list))
+ return -EBUSY; /* already active requests on fd */
+ if (hp->dxfer_len > sfp->reserve_srp->data.dlen)
+ return -ENOMEM; /* MMAP_IO size must fit in reserve */
+ if (hp->flags & SG_FLAG_DIRECT_IO)
+ return -EINVAL; /* not both MMAP_IO and DIRECT_IO */
}
- ul_timeout = msecs_to_jiffies(srp->header.timeout);
+ sfp->cmd_q = true; /* when sg_io_hdr seen, set command queuing on */
+ ul_timeout = msecs_to_jiffies(hp->timeout);
+
timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
- if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof(cmnd))) {
- sg_remove_request(sfp, srp);
+ if (!hp->cmdp || hp->cmd_len < 6 || hp->cmd_len > sizeof(cmnd))
return -EMSGSIZE;
- }
- if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
- sg_remove_request(sfp, srp);
+ if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len))
return -EFAULT; /* protects following copy_from_user()s +
get_user()s */
- }
- if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
- sg_remove_request(sfp, srp);
+ if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len))
return -EFAULT;
- }
- if (read_only && sg_allow_access(file, cmnd)) {
- sg_remove_request(sfp, srp);
+ if (read_only && sg_allow_access(file, cmnd))
return -EPERM;
- }
- k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
- if (k < 0)
- return k;
+ srp = sg_common_write(sfp, hp, NULL, cmnd, sync, timeout);
+ if (IS_ERR(srp))
+ return PTR_ERR(srp);
if (o_srp)
*o_srp = srp;
return count;
}
-static int
-sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
- u8 *cmnd, int timeout, int blocking)
+
+static struct sg_request *
+sg_common_write(struct sg_fd *sfp, const struct sg_io_hdr *hi_p,
+ struct sg_io_v4 *h4p, u8 *cmnd, bool sync, int timeout)
{
bool at_head;
- int k;
+ int res;
struct sg_device *sdp = sfp->parentdp;
- struct sg_io_hdr *hp = &srp->header;
+ struct sg_request *srp;
+ struct sg_io_hdr *hp;
+ if (h4p || !hi_p)
+ return ERR_PTR(-EOPNOTSUPP);
+ srp = sg_add_request(sfp, hi_p->dxfer_len, false);
+ if (IS_ERR(srp))
+ return srp;
+ srp->header = *hi_p; /* structure assignment, could memcpy */
+ hp = &srp->header;
srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
hp->status = 0;
hp->masked_status = 0;
@@ -875,19 +866,18 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
hp->host_status = 0;
hp->driver_status = 0;
hp->resid = 0;
- SG_LOG(4, sfp->parentdp, "%s: scsi opcode=0x%02x, cmd_size=%d\n",
- __func__, (int)cmnd[0], (int)hp->cmd_len);
+ SG_LOG(4, sdp, "%s: scsi opcode=0x%02x, cmd_size=%d\n", __func__,
+ (int)cmnd[0], (int)hp->cmd_len);
if (hp->dxfer_len >= SZ_256M)
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
- k = sg_start_req(srp, cmnd);
- if (k) {
- SG_LOG(1, sfp->parentdp, "%s: start_req err=%d\n", __func__,
- k);
- sg_finish_rem_req(srp);
+ res = sg_start_req(srp, cmnd);
+ if (res) {
+ SG_LOG(1, sdp, "%s: start_req err=%d\n", __func__, -res);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
- return k; /* probably out of space --> ENOMEM */
+ return ERR_PTR(res); /* probably out of space --> ENOMEM */
}
if (atomic_read(&sdp->detaching)) {
if (srp->bio) {
@@ -896,12 +886,15 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
srp->rq = NULL;
}
- sg_finish_rem_req(srp);
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
- return -ENODEV;
+ return ERR_PTR(-ENODEV);
}
- hp->duration = jiffies_to_msecs(jiffies);
+ if (sfp->time_in_ns)
+ srp->start_ts = ktime_get_with_offset(TK_OFFS_BOOT);
+ else
+ hp->duration = jiffies_to_msecs(jiffies);
/* at tail if v3 or later interface and tail flag set */
at_head = !(hp->interface_id != '\0' &&
(SG_FLAG_Q_AT_TAIL & hp->flags));
@@ -910,19 +903,8 @@ sg_common_write(struct sg_fd *sfp, struct sg_request *srp,
kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
srp->rq, (int)at_head, sg_rq_end_io);
- return 0;
-}
-
-static int
-srp_done(struct sg_fd *sfp, struct sg_request *srp)
-{
- unsigned long flags;
- int ret;
-
- read_lock_irqsave(&sfp->rq_list_lock, flags);
- ret = srp->done;
- read_unlock_irqrestore(&sfp->rq_list_lock, flags);
- return ret;
+ /* u32 tag = blk_mq_unique_tag(srp->rq); should now be available */
+ return srp;
}
static int
@@ -935,49 +917,132 @@ max_sectors_bytes(struct request_queue *q)
return max_sectors << 9;
}
+/*
+ * For backward compatibility the duration in nanoseconds is placed in a
+ * 32 bit unsigned integer. This limits the maximum duration that can
+ * be represented (without wrapping) to about 4.3 seconds.
+ */
+static inline u32
+sg_ktime_sub_trunc(ktime_t now_ts, ktime_t ts0)
+{
+ if (ktime_after(now_ts, ts0))
+ return (u32)ktime_to_ns(ktime_sub(now_ts, ts0));
+ else
+ return 0;
+}
+
+/*
+ * Annotation under function arguments (i.e. '__must_hold...') states that
+ * this function expects that lock to be held, a read lock is sufficient in
+ * this case.
+ */
static void
-sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo)
+sg_fill_request_element(struct sg_fd *sfp, struct sg_request *srp,
+ struct sg_req_info *rip)
+ __must_hold(&sfp->rq_list_lock)
+{
+ spin_lock(&srp->rq_entry_lck);
+ rip->req_state = (int)srp->rq_state;
+ rip->problem = srp->header.masked_status & srp->header.host_status &
+ srp->header.driver_status;
+ switch (srp->rq_state) {
+ case SG_RQ_INFLIGHT:
+ if (sfp->time_in_ns) {
+ ktime_t now_ts =
+ ktime_get_with_offset(TK_OFFS_BOOT);
+ ktime_t ts0 = srp->start_ts;
+
+ /* N.B. truncation to fit in 32 bit field */
+ rip->duration = sg_ktime_sub_trunc(now_ts, ts0);
+ } else {
+ unsigned int ms = jiffies_to_msecs(jiffies);
+
+ rip->duration = (ms > srp->header.duration) ?
+ (ms - srp->header.duration) : 0;
+ }
+ break;
+ case SG_RQ_AWAIT_READ:
+ case SG_RQ_DONE_READ:
+ rip->duration = srp->header.duration;
+ break;
+ case SG_RQ_INACTIVE:
+ case SG_RQ_BUSY:
+ default:
+ rip->duration = 0;
+ break;
+ }
+ rip->orphan = srp->orphan;
+ rip->sg_io_owned = srp->sync_invoc;
+ rip->pack_id = srp->header.pack_id;
+ rip->usr_ptr = srp->header.usr_ptr;
+ spin_unlock(&srp->rq_entry_lck);
+}
+
+/*
+ * Populate up to max_num struct sg_req_info objects, first from the active
+ * list then, if there is still room, from the free list. All elements in
+ * the free list should have SG_RQ_INACTIVE status.
+ * See sg_fill_request_element() for note about __must_hold annotation.
+ */
+static void
+sg_fill_request_table(struct sg_fd *sfp, struct sg_req_info *rinfo,
+ int max_num)
+ __must_hold(&sfp->rq_list_lock)
{
struct sg_request *srp;
+ struct sg_req_info *rip;
int val;
- unsigned int ms;
val = 0;
- list_for_each_entry(srp, &sfp->rq_list, entry) {
- if (val >= SG_MAX_QUEUE)
- break;
- rinfo[val].req_state = srp->done + 1;
- rinfo[val].problem =
- srp->header.masked_status &
- srp->header.host_status &
- srp->header.driver_status;
- if (srp->done)
- rinfo[val].duration =
- srp->header.duration;
- else {
- ms = jiffies_to_msecs(jiffies);
- rinfo[val].duration =
- (ms > srp->header.duration) ?
- (ms - srp->header.duration) : 0;
- }
- rinfo[val].orphan = srp->orphan;
- rinfo[val].sg_io_owned = srp->sg_io_owned;
- rinfo[val].pack_id = srp->header.pack_id;
- rinfo[val].usr_ptr = srp->header.usr_ptr;
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
+ if (val >= max_num)
+ return;
+ rip = &rinfo[val];
+ sg_fill_request_element(sfp, srp, rip);
+ val++;
+ }
+ list_for_each_entry(srp, &sfp->rq_free_list, free_entry) {
+ if (val >= max_num)
+ return;
+ rip = &rinfo[val];
+ sg_fill_request_element(sfp, srp, rip);
val++;
}
}
+/*
+ * This function is called from one place: the wait_event_interruptible()
+ * in the synchronous ioctl(SG_IO) call (see sg_ioctl()). Since only one
+ * simple value (a u8) is being read, one argument is that the spinlock
+ * should not be needed. The repercussions of being alerted but not seeing
+ * the new state in srp->rq_state are quite nasty. A middle ground is to
+ * use wait_event_interruptible_lock_irq() .
+ */
+static inline bool
+srp_state_or_detaching(struct sg_device *sdp, struct sg_request *srp)
+{
+ /* unsigned long flags; */
+ bool ret;
+
+ /* spin_lock_irqsave(&srp->rq_entry_lck, flags); */
+ ret = srp->rq_state != SG_RQ_INFLIGHT ||
+ atomic_read(&sdp->detaching);
+ /* spin_unlock_irqrestore(&srp->rq_entry_lck, flags); */
+ return ret;
+}
+
#if 0 /* temporary to shorten big patch */
static long
sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
+ bool leave;
void __user *p = (void __user *)arg;
int __user *ip = p;
int result, val, read_only;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
+ const char *cp;
unsigned long iflags;
sfp = filp->private_data;
@@ -1251,38 +1316,42 @@ sg_compat_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
static __poll_t
sg_poll(struct file *filp, poll_table * wait)
{
- __poll_t res = 0;
+ __poll_t pres = 0;
+ bool empty;
+ unsigned long iflags;
struct sg_device *sdp;
struct sg_fd *sfp;
struct sg_request *srp;
- int count = 0;
- unsigned long iflags;
sfp = filp->private_data;
- if (!sfp)
+ if (IS_ERR_OR_NULL(sfp))
return EPOLLERR;
sdp = sfp->parentdp;
- if (!sdp)
+ if (IS_ERR_OR_NULL(sdp))
return EPOLLERR;
poll_wait(filp, &sfp->read_wait, wait);
read_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_for_each_entry(srp, &sfp->rq_list, entry) {
+ empty = list_empty(&sfp->rq_list);
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
/* if any read waiting, flag it */
- if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
- res = EPOLLIN | EPOLLRDNORM;
- ++count;
+ spin_lock(&srp->rq_entry_lck);
+ if (srp->rq_state == SG_RQ_AWAIT_READ && !srp->sync_invoc) {
+ spin_unlock(&srp->rq_entry_lck);
+ pres = EPOLLIN | EPOLLRDNORM;
+ break;
+ }
+ spin_unlock(&srp->rq_entry_lck);
}
read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
if (atomic_read(&sdp->detaching))
- res |= EPOLLHUP;
- else if (!sfp->cmd_q) {
- if (0 == count)
- res |= EPOLLOUT | EPOLLWRNORM;
- } else if (count < SG_MAX_QUEUE)
- res |= EPOLLOUT | EPOLLWRNORM;
- SG_LOG(3, sdp, "%s: res=0x%x\n", __func__, (__force u32)res);
- return res;
+ pres |= EPOLLHUP;
+ else if (sfp->cmd_q)
+ pres |= EPOLLOUT | EPOLLWRNORM;
+ else if (empty)
+ pres |= EPOLLOUT | EPOLLWRNORM;
+ SG_LOG(3, sdp, "%s: pres=0x%x\n", __func__, (__force u32)pres);
+ return pres;
}
static int
@@ -1292,12 +1361,14 @@ sg_fasync(int fd, struct file *filp, int mode)
struct sg_fd *sfp;
sfp = filp->private_data;
- if (!sfp)
- return -ENXIO;
+ if (IS_ERR_OR_NULL(sfp)) {
+ pr_warn("sg: %s: sfp is NULL or error\n", __func__);
+ return IS_ERR(sfp) ? PTR_ERR(sfp) : -ENXIO;
+ }
sdp = sfp->parentdp;
- if (!sdp)
- return -ENXIO;
SG_LOG(3, sdp, "%s: mode=%d\n", __func__, mode);
+ if (IS_ERR_OR_NULL(sdp))
+ return IS_ERR(sdp) ? PTR_ERR(sdp) : -ENXIO;
return fasync_helper(fd, filp, mode, &sfp->async_qp);
}
@@ -1306,25 +1377,46 @@ static vm_fault_t
sg_vma_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
- struct sg_fd *sfp;
- unsigned long offset, len, sa;
struct sg_scatter_hold *rsv_schp;
+ struct sg_request *srp;
+ struct sg_device *sdp;
+ struct sg_fd *sfp;
int k, length;
+ unsigned long offset, len, sa;
+ const char *nbp = "==NULL, bad";
- if (!vma)
+ if (!vma) {
+ pr_warn("%s: vma%s\n", __func__, nbp);
return VM_FAULT_SIGBUS;
+ }
sfp = vma->vm_private_data;
- if (!sfp)
+ if (IS_ERR_OR_NULL(sfp)) {
+ pr_warn("%s: sfp%s\n", __func__, nbp);
return VM_FAULT_SIGBUS;
- rsv_schp = &sfp->reserve;
- offset = vmf->pgoff << PAGE_SHIFT;
- if (offset >= rsv_schp->dlen)
+ }
+ sdp = sfp->parentdp;
+ if (sdp && unlikely(atomic_read(&sdp->detaching))) {
+ SG_LOG(1, sdp, "%s: device deatching\n", __func__);
return VM_FAULT_SIGBUS;
- SG_LOG(3, sfp->parentdp, "%s: offset=%lu, scatg=%d\n", __func__,
- offset, rsv_schp->num_sgat);
+ }
+ /* guard against ioctl(SG_SET_RESERVED_SIZE) and the like */
+ mutex_lock(&sfp->f_mutex);
+ srp = sfp->reserve_srp;
+ if (!srp) {
+ SG_LOG(1, sdp, "%s: srp%s\n", __func__, nbp);
+ goto out_err;
+ }
+ rsv_schp = &srp->data;
+ offset = vmf->pgoff << PAGE_SHIFT;
+ if (offset >= rsv_schp->dlen) {
+ SG_LOG(1, sdp, "%s: offset>reserve.dlen\n", __func__);
+ goto out_err;
+ }
sa = vma->vm_start;
+ SG_LOG(3, sdp, "%s: vm_start=0x%lx, offset=%lu\n", __func__, sa,
+ offset);
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
len = vma->vm_end - sa;
len = (len < length) ? len : length;
if (offset < len) {
@@ -1332,12 +1424,14 @@ sg_vma_fault(struct vm_fault *vmf)
offset >> PAGE_SHIFT);
get_page(page); /* increment page count */
vmf->page = page;
+ mutex_unlock(&sfp->f_mutex);
return 0; /* success */
}
sa += len;
offset -= len;
}
-
+out_err:
+ mutex_unlock(&sfp->f_mutex);
return VM_FAULT_SIGBUS;
}
@@ -1348,32 +1442,44 @@ static const struct vm_operations_struct sg_mmap_vm_ops
= {
static int
sg_mmap(struct file *filp, struct vm_area_struct *vma)
{
- struct sg_fd *sfp;
- unsigned long req_sz, len, sa;
- struct sg_scatter_hold *rsv_schp;
int k, length;
int ret = 0;
+ unsigned long req_sz, len, sa, iflags;
+ struct sg_scatter_hold *rsv_schp;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
if (!filp || !vma)
return -ENXIO;
sfp = filp->private_data;
- if (!sfp)
- return -ENXIO;
+ if (IS_ERR_OR_NULL(sfp)) {
+ pr_warn("sg: %s: sfp is NULL or error\n", __func__);
+ return IS_ERR(sfp) ? PTR_ERR(sfp) : -ENXIO;
+ }
req_sz = vma->vm_end - vma->vm_start;
- SG_LOG(3, sfp->parentdp, "%s starting, vm_start=%p, len=%d\n",
- __func__, (void *)vma->vm_start, (int)req_sz);
- if (vma->vm_pgoff)
+ SG_LOG(3, sfp->parentdp, "%s: vm_start=%p, len=%d\n", __func__,
+ (void *)vma->vm_start, (int)req_sz);
+ if (vma->vm_pgoff || IS_ERR_OR_NULL(sfp->parentdp))
return -EINVAL; /* want no offset */
- rsv_schp = &sfp->reserve;
+ /*
+ * Assume no requests active on this file descriptor (sfp) so that
+ * the reserve request is on free list
+ */
mutex_lock(&sfp->f_mutex);
+ srp = sfp->reserve_srp;
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
+ if (srp->rq_state != SG_RQ_INACTIVE) {
+ ret = -EBUSY;
+ goto out;
+ }
+ rsv_schp = &srp->data;
if (req_sz > rsv_schp->dlen) {
- ret = -ENOMEM; /* cannot map more than reserved buffer */
+ ret = -ENOMEM;
goto out;
}
-
sa = vma->vm_start;
length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
+ for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
len = vma->vm_end - sa;
len = (len < length) ? len : length;
sa += len;
@@ -1384,6 +1490,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_private_data = sfp;
vma->vm_ops = &sg_mmap_vm_ops;
out:
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
mutex_unlock(&sfp->f_mutex);
return ret;
}
@@ -1399,10 +1506,20 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
static void
sg_rq_end_io_usercontext(struct work_struct *work)
{
- struct sg_request *srp = container_of(work, struct sg_request, ew.work);
- struct sg_fd *sfp = srp->parentfp;
+ struct sg_request *srp = container_of(work, struct sg_request,
+ ew_orph.work);
+ struct sg_fd *sfp;
- sg_finish_rem_req(srp);
+ if (!srp) {
+ WARN_ONCE("s: srp unexpectedly NULL\n", __func__);
+ return;
+ }
+ sfp = srp->parentfp;
+ if (!sfp) {
+ WARN_ONCE(1, "%s: sfp unexpectedly NULL\n", __func__);
+ return;
+ }
+ sg_finish_scsi_blk_rq(srp);
sg_remove_request(sfp, srp);
kref_put(&sfp->f_ref, sg_remove_sfp);
}
@@ -1418,36 +1535,46 @@ static void
sg_rq_end_io(struct request *rq, blk_status_t status)
{
struct sg_request *srp = rq->end_io_data;
- struct scsi_request *req = scsi_req(rq);
+ struct scsi_request *scsi_rp = scsi_req(rq);
struct sg_device *sdp;
struct sg_fd *sfp;
- unsigned long iflags;
- unsigned int ms;
u8 *sense;
- int result, resid, done = 1;
+ unsigned long iflags;
+ int result, resid;
+ enum sg_rq_state rqq_state = SG_RQ_AWAIT_READ;
- if (WARN_ON(srp->done != 0))
+ if (WARN_ON(srp->rq_state != SG_RQ_INFLIGHT))
return;
-
sfp = srp->parentfp;
- if (WARN_ON(sfp == NULL))
+ if (unlikely(!sfp)) {
+ WARN_ONCE(1, "%s: sfp unexpectedly NULL", __func__);
return;
-
+ }
sdp = sfp->parentdp;
if (unlikely(atomic_read(&sdp->detaching)))
pr_info("%s: device detaching\n", __func__);
- sense = req->sense;
- result = req->result;
- resid = req->resid_len;
+ sense = scsi_rp->sense;
+ result = scsi_rp->result;
+ resid = scsi_rp->resid_len;
SG_LOG(4, sdp, "%s: pack_id=%d, res=0x%x\n", __func__,
srp->header.pack_id, result);
srp->header.resid = resid;
- ms = jiffies_to_msecs(jiffies);
- srp->header.duration = (ms > srp->header.duration) ?
- (ms - srp->header.duration) : 0;
- if (0 != result) {
+ if (sfp->time_in_ns) {
+ ktime_t now_ts = ktime_get_with_offset(TK_OFFS_BOOT);
+ ktime_t ts0 = srp->start_ts;
+
+ /* N.B. truncation to fit in 32 bit field */
+ srp->header.duration = ktime_after(now_ts, ts0) ?
+ (u32)ktime_sub(now_ts, ts0) : 0;
+ } else {
+ unsigned int ms = jiffies_to_msecs(jiffies);
+
+ srp->header.duration = (ms > srp->header.duration) ?
+ (ms - srp->header.duration) : 0;
+ }
+ if (unlikely(result)) {
struct scsi_sense_hdr sshdr;
srp->header.status = 0xff & result;
@@ -1473,8 +1600,8 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
}
}
- if (req->sense_len)
- memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
+ if (scsi_rp->sense_len)
+ memcpy(srp->sense_b, scsi_rp->sense, SCSI_SENSE_BUFFERSIZE);
/* Rely on write phase to clean out srp status values, so no "else" */
@@ -1485,29 +1612,30 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
* blk_rq_unmap_user() can be called from user context.
*/
srp->rq = NULL;
- scsi_req_free_cmd(scsi_req(rq));
+ scsi_req_free_cmd(scsi_rp);
__blk_put_request(rq->q, rq);
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
if (unlikely(srp->orphan)) {
if (sfp->keep_orphan)
- srp->sg_io_owned = 0;
+ srp->sync_invoc = false;
else
- done = 0;
+ rqq_state = SG_RQ_BUSY;
}
- srp->done = done;
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ srp->rq_state = rqq_state;
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
- if (likely(done)) {
- /* Now wake up any sg_read() that is waiting for this
- * packet.
+ if (likely(rqq_state == SG_RQ_AWAIT_READ)) {
+ /*
+ * Now wake up any sg_read() or ioctl(SG_IORECEIVE) that is
+ * waiting for this packet.
*/
wake_up_interruptible(&sfp->read_wait);
kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
kref_put(&sfp->f_ref, sg_remove_sfp);
- } else {
- INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
- schedule_work(&srp->ew.work);
+ } else { /* clean up orphaned request that aren't being kept */
+ INIT_WORK(&srp->ew_orph.work, sg_rq_end_io_usercontext);
+ schedule_work(&srp->ew_orph.work);
}
}
@@ -1565,8 +1693,8 @@ sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
}
k = error;
- SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
- "sg_alloc: dev=%d \n", k));
+ SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp, "%s: dev=%d\n",
+ __func__, k));
sprintf(disk->disk_name, "sg%d", k);
disk->first_minor = k;
sdp->disk = disk;
@@ -1710,7 +1838,7 @@ sg_remove_device(struct device *cl_dev, struct
class_interface *cl_intf)
SG_LOG(3, sdp, "%s\n", __func__);
read_lock_irqsave(&sdp->sfd_lock, iflags);
- list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
+ list_for_each_entry(sfp, &sdp->sfds, sfd_entry) {
wake_up_interruptible_all(&sfp->read_wait);
kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
}
@@ -1796,22 +1924,31 @@ exit_sg(void)
static int
sg_start_req(struct sg_request *srp, u8 *cmd)
{
- int res;
struct request *rq;
- struct scsi_request *req;
+ struct scsi_request *scsi_rp;
struct sg_fd *sfp = srp->parentfp;
+ struct sg_device *sdp;
struct sg_io_hdr *hp = &srp->header;
+ struct sg_scatter_hold *req_schp = &srp->data;
+ struct request_queue *q;
+ struct rq_map_data *md;
+ u8 *long_cmdp = NULL;
+ bool reserved;
+ int res;
int dxfer_len = (int)hp->dxfer_len;
int dxfer_dir = hp->dxfer_direction;
- unsigned int iov_count = hp->iovec_count;
- struct sg_scatter_hold *req_schp = &srp->data;
- struct sg_scatter_hold *rsv_schp = &sfp->reserve;
- struct request_queue *q = sfp->parentdp->device->request_queue;
- struct rq_map_data *md, map_data;
int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
- u8 *long_cmdp = NULL;
+ unsigned long iflags;
+ unsigned int iov_count = hp->iovec_count;
+ struct rq_map_data map_data;
- SG_LOG(4, sfp->parentdp, "%s: dxfer_len=%d\n", __func__, dxfer_len);
+ if (unlikely(!sfp)) {
+ WARN_ONCE(1, "%s: sfp unexpectedly NULL", __func__);
+ return -EBADF;
+ }
+ sdp = sfp->parentdp;
+ SG_LOG(4, sdp, "%s: dxfer_len=%d\n", __func__, dxfer_len);
+ q = sdp->device->request_queue;
if (hp->cmd_len > BLK_MAX_CDB) {
long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
@@ -1831,51 +1968,51 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
* not expect an EWOULDBLOCK from this condition.
*/
rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
- REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
+ REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
if (IS_ERR(rq)) {
kfree(long_cmdp);
return PTR_ERR(rq);
}
- req = scsi_req(rq);
+ spin_lock_irqsave(&srp->rq_entry_lck, iflags);
+ scsi_rp = scsi_req(rq);
if (hp->cmd_len > BLK_MAX_CDB)
- req->cmd = long_cmdp;
- memcpy(req->cmd, cmd, hp->cmd_len);
- req->cmd_len = hp->cmd_len;
+ scsi_rp->cmd = long_cmdp;
+ memcpy(scsi_rp->cmd, cmd, hp->cmd_len);
+ scsi_rp->cmd_len = hp->cmd_len;
srp->rq = rq;
rq->end_io_data = srp;
- req->retries = SG_DEFAULT_RETRIES;
+ scsi_rp->retries = SG_DEFAULT_RETRIES;
+ srp->rq_state = SG_RQ_INFLIGHT;
+ reserved = (sfp->reserve_srp == srp);
+ spin_unlock_irqrestore(&srp->rq_entry_lck, iflags);
if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
return 0;
- if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
+ if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
- !sfp->parentdp->device->host->unchecked_isa_dma &&
+ !sdp->device->host->unchecked_isa_dma &&
blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
- md = NULL;
+ md = NULL; /* direct IO activate */
else
md = &map_data;
if (md) {
mutex_lock(&sfp->f_mutex);
- if (dxfer_len <= rsv_schp->dlen &&
- !sfp->res_in_use) {
- sfp->res_in_use = true;
- sg_link_reserve(sfp, srp, dxfer_len);
- } else if (hp->flags & SG_FLAG_MMAP_IO) {
- res = -EBUSY; /* sfp->res_in_use == true */
- if (dxfer_len > rsv_schp->dlen)
- res = -ENOMEM;
- mutex_unlock(&sfp->f_mutex);
- return res;
- } else {
- res = sg_build_indirect(req_schp, sfp, dxfer_len);
- if (res) {
+ if (hp->flags & SG_FLAG_MMAP_IO) {
+ if (!reserved || dxfer_len > req_schp->dlen) {
+ res = reserved ? -ENOMEM : -EBUSY;
mutex_unlock(&sfp->f_mutex);
return res;
}
+ } else if (req_schp->dlen == 0) {
+ res = sg_mk_sgat_dlen(srp, sfp, dxfer_len);
+ if (res) {
+ mutex_unlock(&sfp->f_mutex);
+ return res; /* will be negated errno */
+ }
}
mutex_unlock(&sfp->f_mutex);
@@ -1918,70 +2055,70 @@ sg_start_req(struct sg_request *srp, u8 *cmd)
hp->info |= SG_INFO_DIRECT_IO;
}
}
+ SG_LOG(6, sdp, "%s: started, %siovec_count=%u\n", __func__,
+ (md ? "" : "direct_io, "), iov_count);
return res;
}
-static int
-sg_finish_rem_req(struct sg_request *srp)
+/* clean up mid-level + block layer objects associate with finished request */
+static void
+sg_finish_scsi_blk_rq(struct sg_request *srp)
{
int ret = 0;
-
struct sg_fd *sfp = srp->parentfp;
- struct sg_scatter_hold *req_schp = &srp->data;
- SG_LOG(4, sfp->parentdp, "%s: res_used=%d\n", __func__,
- (int)srp->res_used);
- if (srp->bio)
+ if (unlikely(!sfp))
+ pr_warn("sg: %s: sfp unexpectedly NULL", __func__);
+ else
+ SG_LOG(4, sfp->parentdp, "%s: srp=0x%p%s\n", __func__, srp,
+ (sfp->reserve_srp == srp) ? " reserve" : "");
+ if (srp->bio) {
ret = blk_rq_unmap_user(srp->bio);
-
+ srp->bio = NULL;
+ }
if (srp->rq) {
scsi_req_free_cmd(scsi_req(srp->rq));
blk_put_request(srp->rq);
+ srp->rq = NULL;
}
-
- if (srp->res_used)
- sg_unlink_reserve(sfp, srp);
- else
- sg_remove_scat(sfp, req_schp);
-
- return ret;
}
static int
sg_build_sgat(struct sg_scatter_hold *schp, const struct sg_fd *sfp,
int tablesize)
{
- int sg_bufflen = tablesize * sizeof(struct page *);
+ int sgat_arrlen = tablesize * sizeof(struct page *);
gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
- schp->pages = kzalloc(sg_bufflen, gfp_flags);
- if (!schp->pages)
+ schp->pages = kzalloc(sgat_arrlen, gfp_flags);
+ if (unlikely(!schp->pages))
return -ENOMEM;
return tablesize; /* number of scat_gath elements allocated */
}
+/* Returns 0 for good, otherwise negated errno value */
static int
-sg_build_indirect(struct sg_scatter_hold *schp, struct sg_fd *sfp,
- int buff_size)
+sg_mk_sgat_dlen(struct sg_request *srp, struct sg_fd *sfp, int dlen)
{
- int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
+ int i, k, rem_sz, num, mx_sc_elems, order, align_sz;
+ int blk_size = dlen;
+ int ret_sz = 0;
int sg_tablesize = sfp->parentdp->sg_tablesize;
- int blk_size = buff_size, order;
gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
struct sg_device *sdp = sfp->parentdp;
+ struct sg_scatter_hold *schp = &srp->data;
- if (blk_size < 0)
+ if (unlikely(blk_size < 0))
return -EFAULT;
- if (0 == blk_size)
- ++blk_size; /* don't know why */
+ if (unlikely(blk_size == 0))
+ ++blk_size; /* don't remember why */
/* round request up to next highest SG_SECTOR_SZ byte boundary */
- blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
- SG_LOG(4, sfp->parentdp, "%s: buff_size=%d, blk_size=%d\n",
- __func__, buff_size, blk_size);
+ align_sz = ALIGN(blk_size, SG_SECTOR_SZ);
+ SG_LOG(4, sdp, "%s: dlen=%d, align_sz=%d\n", __func__, dlen, align_sz);
/* N.B. ret_sz carried into this block ... */
mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
- if (mx_sc_elems < 0)
+ if (unlikely(mx_sc_elems < 0))
return mx_sc_elems; /* most likely -ENOMEM */
num = scatter_elem_sz;
@@ -1993,22 +2130,22 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct
sg_fd *sfp,
scatter_elem_sz_prev = num;
}
- if (sdp->device->host->unchecked_isa_dma)
+ if (sdp && sdp->device->host->unchecked_isa_dma)
gfp_mask |= GFP_DMA;
order = get_order(num);
retry:
ret_sz = 1 << (PAGE_SHIFT + order);
- for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
- k++, rem_sz -= ret_sz) {
+ for (k = 0, rem_sz = align_sz; rem_sz > 0 && k < mx_sc_elems;
+ ++k, rem_sz -= ret_sz) {
num = (rem_sz > scatter_elem_sz_prev) ?
scatter_elem_sz_prev : rem_sz;
schp->pages[k] = alloc_pages(gfp_mask, order);
if (!schp->pages[k])
- goto out;
+ goto err_out;
if (num == scatter_elem_sz_prev) {
if (unlikely(ret_sz > scatter_elem_sz_prev)) {
@@ -2017,20 +2154,20 @@ sg_build_indirect(struct sg_scatter_hold *schp, struct
sg_fd *sfp,
}
}
- SG_LOG(5, sfp->parentdp, "%s: k=%d, num=%d, ret_sz=%d\n",
- __func__, k, num, ret_sz);
- } /* end of for loop */
+ SG_LOG(5, sdp, "%s: k=%d, num=%d, ret_sz=%d\n", __func__, k,
+ num, ret_sz);
+ } /* end of for loop */
schp->page_order = order;
schp->num_sgat = k;
- SG_LOG(5, sfp->parentdp, "%s: num_sgat=%d, rem_sz=%d\n", __func__, k,
- rem_sz);
-
- schp->dlen = blk_size;
- if (rem_sz > 0) /* must have failed */
+ SG_LOG(5, sdp, "%s: num_sgat=%d, rem_sz=%d\n", __func__, k, rem_sz);
+ if (unlikely(rem_sz > 0)) /* must have failed */
return -ENOMEM;
+ schp->dlen = align_sz;
+ if (sfp->tot_fd_thresh > 0)
+ atomic_add(align_sz, &sfp->sum_fd_dlens);
return 0;
-out:
+err_out:
for (i = 0; i < k; i++)
__free_pages(schp->pages[i], order);
@@ -2040,138 +2177,175 @@ sg_build_indirect(struct sg_scatter_hold *schp,
struct sg_fd *sfp,
return -ENOMEM;
}
+/* Remove the data (possibly a sgat list) held by srp, not srp itself */
static void
-sg_remove_scat(struct sg_fd *sfp, struct sg_scatter_hold *schp)
+sg_remove_sgat(struct sg_request *srp)
{
- SG_LOG(4, sfp->parentdp, "%s: num_sgat=%d\n", __func__,
- schp->num_sgat);
- if (schp->pages) {
- if (!schp->dio_in_use) {
- int k;
-
- for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
- SG_LOG(5, sfp->parentdp, "%s: k=%d, pg=0x%p\n",
- __func__, k, schp->pages[k]);
- __free_pages(schp->pages[k], schp->page_order);
- }
+ int k;
+ void *p;
+ struct sg_scatter_hold *schp = &srp->data;
+ struct sg_fd *sfp = srp->parentfp;
+ struct sg_device *sdp;
+
+ sdp = (sfp ? sfp->parentdp : NULL);
+ SG_LOG(4, sdp, "%s: num_sgat=%d%s\n", __func__, schp->num_sgat,
+ (srp->parentfp ? (srp == sfp->reserve_srp) : false) ?
+ " [reserve]" : "");
+ if (schp->pages && !schp->dio_in_use) {
+ for (k = 0; k < schp->num_sgat; ++k) {
+ p = schp->pages[k];
+ SG_LOG(5, sdp, "%s: pg[%d]=0x%p\n", __func__, k, p);
+ if (unlikely(!p))
+ continue;
+ __free_pages(p, schp->page_order);
+ }
+ SG_LOG(5, sdp, "%s: pgs=0x%p\n", __func__, schp->pages);
+ }
+ if (sfp->tot_fd_thresh > 0) {
+ int dl = srp->data.dlen;
- kfree(schp->pages);
+ /* this is a subtraction, error if it goes negative */
+ if (atomic_add_negative(-dl, &sfp->sum_fd_dlens)) {
+ SG_LOG(2, sfp->parentdp,
+ "%s: logic error: this dlen > %s\n",
+ __func__, "sum_fd_dlens");
+ atomic_set(&sfp->sum_fd_dlens, 0);
}
}
memset(schp, 0, sizeof(*schp));
}
+/*
+ * sg v1 and v2 interface: with a command yielding a data-in buffer, after
+ * it has arrived in kernel memory, this function copies it to the user
+ * space, appended to given struct sg_header object. Return 0 if okay, else
+ * a negated errno value.
+ */
static int
-sg_read_oxfer(struct sg_request *srp, char __user *outp, int num_read_xfer)
+sg_read_oxfer(struct sg_request *srp, char __user *outp, int num_xfer)
{
+ int k, num, res;
+ struct page *pgp;
struct sg_scatter_hold *schp = &srp->data;
- int k, num;
- SG_LOG(4, srp->parentfp->parentdp, "%s: num_read_xfer=%d\n", __func__,
- num_read_xfer);
- if ((!outp) || (num_read_xfer <= 0))
- return 0;
+ SG_LOG(4, srp->parentfp->parentdp, "%s: num_xfer=%d\n", __func__,
+ num_xfer);
+ if (unlikely(!outp || num_xfer <= 0))
+ return (num_xfer == 0 && outp) ? 0 : -EINVAL;
num = 1 << (PAGE_SHIFT + schp->page_order);
- for (k = 0; k < schp->num_sgat && schp->pages[k]; k++) {
- if (num > num_read_xfer) {
- if (__copy_to_user(outp, page_address(schp->pages[k]),
- num_read_xfer))
- return -EFAULT;
+ for (k = 0, res = 0; k < schp->num_sgat; ++k) {
+ pgp = schp->pages[k];
+ if (unlikely(!pgp)) {
+ res = -ENXIO;
+ break;
+ }
+ if (num > num_xfer) {
+ if (__copy_to_user(outp, page_address(pgp), num_xfer))
+ res = -EFAULT;
break;
} else {
- if (__copy_to_user(outp, page_address(schp->pages[k]),
- num))
- return -EFAULT;
- num_read_xfer -= num;
- if (num_read_xfer <= 0)
+ if (__copy_to_user(outp, page_address(pgp), num)) {
+ res = -EFAULT;
+ break;
+ }
+ num_xfer -= num;
+ if (num_xfer <= 0)
break;
outp += num;
}
}
-
- return 0;
-}
-
-static void
-sg_build_reserve(struct sg_fd *sfp, int req_size)
-{
- struct sg_scatter_hold *schp = &sfp->reserve;
-
- SG_LOG(4, sfp->parentdp, "%s: req_size=%d\n", __func__, req_size);
- do {
- if (req_size < PAGE_SIZE)
- req_size = PAGE_SIZE;
- if (0 == sg_build_indirect(schp, sfp, req_size))
- return;
- else
- sg_remove_scat(sfp, schp);
- req_size >>= 1; /* divide by 2 */
- } while (req_size > (PAGE_SIZE / 2));
+ return res;
}
-static void
-sg_link_reserve(struct sg_fd *sfp, struct sg_request *srp, int size)
+static struct sg_request *
+sg_get_rq_pack_id(struct sg_fd *sfp, int pack_id)
{
- struct sg_scatter_hold *req_schp = &srp->data;
- struct sg_scatter_hold *rsv_schp = &sfp->reserve;
- int k, num, rem;
-
- srp->res_used = true;
- SG_LOG(4, sfp->parentdp, "%s: size=%d\n", __func__, size);
- rem = size;
-
- num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
- for (k = 0; k < rsv_schp->num_sgat; k++) {
- if (rem <= num) {
- req_schp->num_sgat = k + 1;
- req_schp->pages = rsv_schp->pages;
+ struct sg_request *srp;
+ unsigned long iflags;
- req_schp->dlen = size;
- req_schp->page_order = rsv_schp->page_order;
- break;
- } else
- rem -= num;
+ read_lock_irqsave(&sfp->rq_list_lock, iflags);
+ list_for_each_entry(srp, &sfp->rq_list, rq_entry) {
+ spin_lock(&srp->rq_entry_lck);
+ /* look for requests that are ready + not SG_IO owned */
+ if ((srp->rq_state == SG_RQ_AWAIT_READ) && !srp->sync_invoc &&
+ (pack_id == -1 || srp->header.pack_id == pack_id)) {
+ /* guard against other readers */
+ srp->rq_state = SG_RQ_DONE_READ;
+ spin_unlock(&srp->rq_entry_lck);
+ read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return srp;
+ }
+ spin_unlock(&srp->rq_entry_lck);
}
-
- if (k >= rsv_schp->num_sgat)
- SG_LOG(1, sfp->parentdp, "%s: BAD size\n", __func__);
+ read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ return NULL;
}
-static void
-sg_unlink_reserve(struct sg_fd *sfp, struct sg_request *srp)
+/* If rwlp and iflagsp non-NULL then release and re-take write lock */
+static struct sg_request *
+sg_mk_srp(struct sg_fd *sfp, bool first, rwlock_t *rwlp,
+ unsigned long *iflagsp)
{
- struct sg_scatter_hold *req_schp = &srp->data;
+ struct sg_request *srp;
+ int gfp = __GFP_NOWARN;
- SG_LOG(4, srp->parentfp->parentdp, "%s: req->num_sgat=%d\n", __func__,
- (int)req_schp->num_sgat);
- req_schp->num_sgat = 0;
- req_schp->dlen = 0;
- req_schp->pages = NULL;
- req_schp->page_order = 0;
- srp->res_used = false;
- /* Called without mutex lock to avoid deadlock */
- sfp->res_in_use = false;
+ if (first) { /* prepared to wait if none already outstanding */
+ if (rwlp && iflagsp) {
+ write_unlock_irqrestore(rwlp, *iflagsp);
+ srp = kzalloc(sizeof(*srp), gfp | GFP_KERNEL);
+ write_lock_irqsave(rwlp, *iflagsp);
+ } else
+ srp = kzalloc(sizeof(*srp), gfp | GFP_KERNEL);
+ } else
+ srp = kzalloc(sizeof(*srp), gfp | GFP_ATOMIC);
+ if (srp) {
+ spin_lock_init(&srp->rq_entry_lck);
+ srp->rq_state = SG_RQ_INACTIVE;
+ srp->parentfp = sfp;
+ return srp;
+ } else
+ return ERR_PTR(-ENOMEM);
}
+/*
+ * Irrespective of the given reserve buffer size, the minimum size requested
+ * will be PAGE_SIZE (often that is 4096 bytes). Returns a pointer to reserve
+ * object or a negated errno value twisted by ERR_PTR() macro. The actual
+ * number of bytes allocated (maybe less than dlen) is in srp->data.dlen .
+ * Note that this function is only called in contexts where locking is
+ * not required.
+ */
static struct sg_request *
-sg_get_rq_pack_id(struct sg_fd *sfp, int pack_id)
+sg_build_reserve(struct sg_fd *sfp, int dlen)
{
- struct sg_request *resp;
- unsigned long iflags;
+ bool go_out = false;
+ int res;
+ struct sg_device *sdp = sfp ? sfp->parentdp : NULL;
+ struct sg_request *srp;
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
- list_for_each_entry(resp, &sfp->rq_list, entry) {
- /* look for requests that are ready + not SG_IO owned */
- if ((1 == resp->done) && (!resp->sg_io_owned) &&
- ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
- resp->done = 2; /* guard against other readers */
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return resp;
+ SG_LOG(3, sdp, "%s: dlen=%d\n", __func__, dlen);
+ srp = sg_mk_srp(sfp, list_empty(&sfp->rq_free_list), NULL, NULL);
+ if (IS_ERR(srp))
+ return srp;
+ sfp->reserve_srp = srp;
+ do {
+ if (dlen < PAGE_SIZE) {
+ dlen = PAGE_SIZE;
+ go_out = true;
}
- }
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return NULL;
+ res = sg_mk_sgat_dlen(srp, sfp, dlen);
+ if (res == 0) {
+ SG_LOG(4, sdp, "%s: final dlen=%d, srp=0x%p\n",
+ __func__, dlen, srp);
+ return srp;
+ }
+ if (go_out)
+ return ERR_PTR(res);
+ /* failed so remove, halve dlen, try again */
+ sg_remove_sgat(srp);
+ dlen >>= 1; /* divide by 2 */
+ } while (true);
}
/*
@@ -2181,33 +2355,85 @@ sg_get_rq_pack_id(struct sg_fd *sfp, int pack_id)
* negated errno value twisted by ERR_PTR() macro.
*/
static struct sg_request *
-sg_add_request(struct sg_fd *sfp)
+sg_add_request(struct sg_fd *sfp, int dxfr_len, bool sync)
{
- int k;
+ bool done = false;
+ u32 sum_dlen;
unsigned long iflags;
- struct sg_request *rp = sfp->req_arr;
+ struct sg_request *srp = NULL;
+ struct sg_device *sdp;
+ const char *cp = "fail";
write_lock_irqsave(&sfp->rq_list_lock, iflags);
- if (!list_empty(&sfp->rq_list)) {
- if (!sfp->cmd_q)
- goto out_unlock;
-
- for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
- if (!rp->parentfp)
- break;
+ sdp = sfp->parentdp;
+ if (!list_empty(&sfp->rq_free_list)) {
+ /* when no data xfer, take last if not reserve request */
+ if (dxfr_len < 1) {
+ srp = list_last_entry(&sfp->rq_free_list,
+ struct sg_request, free_entry);
+ spin_lock(&srp->rq_entry_lck);
+ if (srp->rq_state == SG_RQ_INACTIVE &&
+ sfp->reserve_srp != srp) {
+ srp->rq_state = SG_RQ_BUSY;
+ cp = "re-using last in fl";
+ done = true;
+ } else
+ spin_unlock(&srp->rq_entry_lck);
+ } else { /* find request with large enough dlen */
+ list_for_each_entry(srp, &sfp->rq_free_list,
+ free_entry) {
+ spin_lock(&srp->rq_entry_lck);
+ if (srp->rq_state == SG_RQ_INACTIVE &&
+ srp->data.dlen >= dxfr_len) {
+ srp->rq_state = SG_RQ_BUSY;
+ cp = "re-using from start of fl";
+ done = true;
+ break;
+ }
+ spin_unlock(&srp->rq_entry_lck);
+ }
}
- if (k >= SG_MAX_QUEUE)
- goto out_unlock;
+ if (done) {
+ list_del(&srp->free_entry);
+ /* re-using request, may sure it's clean */
+ srp->orphan = false;
+ srp->v4_active = false;
+ srp->rq_state = SG_RQ_INACTIVE;
+ srp->d2p = NULL;
+ } else
+ srp = NULL;
}
- memset(rp, 0, sizeof(*rp));
- rp->parentfp = sfp;
- rp->header.duration = jiffies_to_msecs(jiffies);
- list_add_tail(&rp->entry, &sfp->rq_list);
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return rp;
-out_unlock:
+ if (!done) { /* Need new sg_request object */
+ bool empty = list_empty(&sfp->rq_list);
+
+ if (!sfp->cmd_q && !empty) {
+ srp = ERR_PTR(-EDOM);
+ SG_LOG(6, sdp, "%s: cmd_q false, trying second rq\n",
+ __func__);
+ goto out_wr_unlock;
+ }
+ if (sfp->tot_fd_thresh > 0) {
+ sum_dlen = atomic_read(&sfp->sum_fd_dlens) + dxfr_len;
+ if (sum_dlen > sfp->tot_fd_thresh) {
+ srp = ERR_PTR(-E2BIG);
+ SG_LOG(2, sdp, "%s: sum_of_dlen(%u) > %s\n",
+ __func__, sum_dlen, "tot_fd_thresh");
+ goto out_wr_unlock;
+ }
+ }
+ srp = sg_mk_srp(sfp, empty, &sfp->rq_list_lock, &iflags);
+ if (IS_ERR(srp))
+ goto out_wr_unlock;
+ cp = "new";
+ }
+ srp->sync_invoc = sync;
+ if (done)
+ spin_unlock(&srp->rq_entry_lck);
+ list_add_tail(&srp->rq_entry, &sfp->rq_list);
+out_wr_unlock:
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return NULL;
+ SG_LOG(6, sdp, "%s: %s srp=0x%p\n", __func__, cp, srp);
+ return srp;
}
/*
@@ -2218,38 +2444,88 @@ sg_add_request(struct sg_fd *sfp)
* data length exceeds rem_sgat_thresh then the data (or sgat) is
* cleared and the request is appended to the tail of the free list.
*/
-static int
+static void
sg_remove_request(struct sg_fd *sfp, struct sg_request *srp)
{
+ bool reserve, done;
unsigned long iflags;
- int res = 0;
+ struct sg_request *t_srp;
+ const char *cp = "head";
+ char b[64];
- if (!sfp || !srp || list_empty(&sfp->rq_list))
- return res;
+ if (WARN_ON(!sfp || !srp))
+ return;
write_lock_irqsave(&sfp->rq_list_lock, iflags);
- if (!list_empty(&srp->entry)) {
- list_del(&srp->entry);
- srp->parentfp = NULL;
- res = 1;
- }
+ spin_lock(&srp->rq_entry_lck);
+ /*
+ * N.B. sg_request object is not de-allocated (freed). The contents
+ * of the rq_list and rq_free_list lists are de-allocated (freed) when
+ * the owning file descriptor is closed. The free list acts as a LIFO
+ * for same size (dlen) sg_request objects. This can improve the
+ * chance of a cache hit when the sg_request object is re-used.
+ */
+ reserve = (sfp->reserve_srp == srp);
+ if (reserve || srp->data.dlen <= sfp->rem_sgat_thresh) {
+ list_del(&srp->rq_entry);
+ /* want ascending free list by dlen, but dlen==0 at end */
+ done = false;
+ if (srp->data.dlen > 0) {
+ list_for_each_entry(t_srp, &sfp->rq_free_list,
+ free_entry) {
+ if (srp->data.dlen <= t_srp->data.dlen ||
+ t_srp->data.dlen == 0) {
+ /* add srp _before_ t_srp on fl */
+ list_add_tail(&srp->free_entry,
+ &t_srp->free_entry);
+ done = true;
+ break;
+ }
+ }
+ }
+ if (!done) { /* either empty list, dlen=0 or dlen highest */
+ list_add_tail(&srp->free_entry, &sfp->rq_free_list);
+ cp = "tail";
+ }
+ snprintf(b, sizeof(b), "%ssrp=0x%p move to fl %s",
+ (reserve ? "reserve " : ""), srp, cp);
+ } else {
+ srp->rq_state = SG_RQ_BUSY;
+ list_del(&srp->rq_entry);
+ spin_unlock(&srp->rq_entry_lck);
+ write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
+ sg_remove_sgat(srp);
+ /* don't kfree(srp), move clear request to tail of fl */
+ write_lock_irqsave(&sfp->rq_list_lock, iflags);
+ spin_lock(&srp->rq_entry_lck);
+ list_add_tail(&srp->free_entry, &sfp->rq_free_list);
+ snprintf(b, sizeof(b), "clear sgat srp=0x%p move to fl tail",
+ srp);
+ }
+ srp->rq_state = SG_RQ_INACTIVE;
+ spin_unlock(&srp->rq_entry_lck);
write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
- return res;
+ SG_LOG(5, sfp->parentdp, "%s: %s\n", __func__, b);
}
static struct sg_fd *
sg_add_sfp(struct sg_device *sdp)
{
- struct sg_fd *sfp;
+ bool reduced = false;
+ int dlen;
unsigned long iflags;
- int bufflen;
+ long err;
+ struct sg_fd *sfp;
+ struct sg_request *srp;
sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
- if (!sfp)
+ if (!sfp) {
+ SG_LOG(1, sdp, "%s: sfp allocation failed\n", __func__);
return ERR_PTR(-ENOMEM);
-
+ }
init_waitqueue_head(&sfp->read_wait);
rwlock_init(&sfp->rq_list_lock);
INIT_LIST_HEAD(&sfp->rq_list);
+ INIT_LIST_HEAD(&sfp->rq_free_list);
kref_init(&sfp->f_ref);
mutex_init(&sfp->f_mutex);
sfp->timeout = SG_DEFAULT_TIMEOUT;
@@ -2257,27 +2533,50 @@ sg_add_sfp(struct sg_device *sdp)
sfp->force_packid = !!SG_DEF_FORCE_PACK_ID;
sfp->cmd_q = !!SG_DEF_COMMAND_Q;
sfp->keep_orphan = !!SG_DEF_KEEP_ORPHAN;
+ dlen = (def_reserved_size > SG_RQ_DATA_THRESHOLD) ?
+ def_reserved_size : SG_RQ_DATA_THRESHOLD;
+ sfp->rem_sgat_thresh = dlen;
+ dlen *= 2;
+ sfp->tot_fd_thresh = (dlen > SG_TOT_FD_THRESHOLD) ?
+ dlen : SG_TOT_FD_THRESHOLD;
+ atomic_set(&sfp->sum_fd_dlens, 0);
+ sfp->time_in_ns = !!SG_DEF_TIME_UNIT;
sfp->parentdp = sdp;
- write_lock_irqsave(&sdp->sfd_lock, iflags);
if (atomic_read(&sdp->detaching)) {
- write_unlock_irqrestore(&sdp->sfd_lock, iflags);
kfree(sfp);
+ SG_LOG(1, sdp, "%s: detaching\n", __func__);
return ERR_PTR(-ENODEV);
}
- list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
- write_unlock_irqrestore(&sdp->sfd_lock, iflags);
- SG_LOG(3, sdp, "%s: sfp=0x%p\n", __func__, sfp);
if (unlikely(sg_big_buff != def_reserved_size))
sg_big_buff = def_reserved_size;
- bufflen = min_t(int, sg_big_buff,
+ dlen = min_t(int, sg_big_buff,
max_sectors_bytes(sdp->device->request_queue));
- sg_build_reserve(sfp, bufflen);
- SG_LOG(3, sdp, "%s: dlen=%d, num_sgat=%d\n", __func__,
- sfp->reserve.dlen, sfp->reserve.num_sgat);
-
+ if (dlen > 0) {
+ srp = sg_build_reserve(sfp, dlen);
+ if (IS_ERR(srp)) {
+ kfree(sfp);
+ err = PTR_ERR(srp);
+ SG_LOG(1, sdp, "%s: build reserve err=%ld\n", __func__,
+ -err);
+ return ERR_PTR(err);
+ }
+ if (srp->data.dlen < dlen) {
+ reduced = true;
+ SG_LOG(2, sdp,
+ "%s: reserve reduced from %d to dlen=%d\n",
+ __func__, dlen, srp->data.dlen);
+ }
+ list_add_tail(&srp->free_entry, &sfp->rq_free_list);
+ }
+ if (!reduced)
+ SG_LOG(4, sdp, "%s: built reserve dlen=%d\n", __func__, dlen);
+ write_lock_irqsave(&sdp->sfd_lock, iflags);
+ list_add_tail(&sfp->sfd_entry, &sdp->sfds);
kref_get(&sdp->d_ref);
__module_get(THIS_MODULE);
+ write_unlock_irqrestore(&sdp->sfd_lock, iflags);
+ SG_LOG(3, sdp, "%s: sfp=0x%p success\n", __func__, sfp);
return sfp;
}
@@ -2295,31 +2594,35 @@ sg_remove_sfp_usercontext(struct work_struct *work)
struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
struct sg_device *sdp = sfp->parentdp;
struct sg_request *srp;
- unsigned long iflags;
+ const char *cp = " srp=0x";
/* Cleanup any responses which were never read(). */
- write_lock_irqsave(&sfp->rq_list_lock, iflags);
while (!list_empty(&sfp->rq_list)) {
- srp = list_first_entry(&sfp->rq_list, struct sg_request,
- entry);
- sg_finish_rem_req(srp);
- list_del(&srp->entry);
- srp->parentfp = NULL;
- }
- write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
-
- if (sfp->reserve.dlen > 0) {
- SG_LOG(6, sdp, "%s: dlen=%d, num_sgat=%d\n", __func__,
- (int)sfp->reserve.dlen,
- (int)sfp->reserve.num_sgat);
- sg_remove_scat(sfp, &sfp->reserve);
+ srp = list_last_entry(&sfp->rq_list, struct sg_request,
+ rq_entry);
+ sg_finish_scsi_blk_rq(srp);
+ list_del(&srp->rq_entry);
+ if (srp->data.dlen > 0)
+ sg_remove_sgat(srp);
+ SG_LOG(6, sdp, "%s:%s%p\n", __func__, cp, srp);
+ kfree(srp);
+ }
+ while (!list_empty(&sfp->rq_free_list)) {
+ srp = list_last_entry(&sfp->rq_free_list, struct sg_request,
+ free_entry);
+ list_del(&srp->free_entry);
+ if (srp->data.dlen > 0)
+ sg_remove_sgat(srp);
+ SG_LOG(6, sdp, "%s: free list%s%p\n", __func__, cp, srp);
+ kfree(srp);
}
-
SG_LOG(6, sdp, "%s: sfp=0x%p\n", __func__, sfp);
kfree(sfp);
- scsi_device_put(sdp->device);
- kref_put(&sdp->d_ref, sg_device_destroy);
+ if (sdp) {
+ scsi_device_put(sdp->device);
+ kref_put(&sdp->d_ref, sg_device_destroy);
+ }
module_put(THIS_MODULE);
}
@@ -2331,7 +2634,7 @@ sg_remove_sfp(struct kref *kref)
unsigned long iflags;
write_lock_irqsave(&sdp->sfd_lock, iflags);
- list_del(&sfp->sfd_siblings);
+ list_del(&sfp->sfd_entry);
write_unlock_irqrestore(&sdp->sfd_lock, iflags);
INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
@@ -2341,6 +2644,7 @@ sg_remove_sfp(struct kref *kref)
#ifdef CONFIG_SCSI_PROC_FS
static int
sg_idr_max_id(int id, void *p, void *data)
+ __must_hold(&sg_index_lock)
{
int *k = data;
@@ -2363,9 +2667,9 @@ sg_last_dev(void)
}
#endif
-/* must be called with sg_index_lock held */
static struct sg_device *
sg_lookup_dev(int dev)
+ __must_hold(&sg_index_lock)
{
return idr_find(&sg_index_idr, dev);
}
@@ -2375,13 +2679,13 @@ sg_lookup_dev(int dev)
* errno value on failure. Does not return NULL.
*/
static struct sg_device *
-sg_get_dev(int dev)
+sg_get_dev(int min_dev)
{
struct sg_device *sdp;
unsigned long flags;
read_lock_irqsave(&sg_index_lock, flags);
- sdp = sg_lookup_dev(dev);
+ sdp = sg_lookup_dev(min_dev);
if (!sdp)
sdp = ERR_PTR(-ENXIO);
else if (atomic_read(&sdp->detaching)) {
@@ -2475,6 +2779,7 @@ sg_proc_init(void)
return 0;
}
+
static int
sg_proc_seq_show_int(struct seq_file *s, void *v)
{
--
2.17.1
