Currently we cap the rsize at a value that fits in CIFSMaxBufSize. That's
not needed any longer for readpages. Allow the use of larger values for
readpages.
cifs_iovec_read and cifs_read however are still limited to the
CIFSMaxBufSize. While we're at it, make sure we error out if the rsize
and wsize are less than PAGE_CACHE_SIZE. Although it has never been
enforced at mount time, cifs.ko has never handled those cases properly.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/cifs/connect.c | 101 +++++++++++++++++++++++++++++++----------------------
fs/cifs/file.c | 12 +++++-
2 files changed, 69 insertions(+), 44 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index fc0ea41..9261b91 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1301,11 +1301,23 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
if (value && *value) {
vol->rsize =
simple_strtoul(value, &value, 0);
+ /* rsize has a floor of 1 page */
+ if (vol->rsize < PAGE_CACHE_SIZE) {
+ cERROR(1, "minimum rsize is %lu",
+ PAGE_CACHE_SIZE);
+ goto cifs_parse_mount_err;
+ }
}
} else if (strnicmp(data, "wsize", 5) == 0) {
if (value && *value) {
vol->wsize =
simple_strtoul(value, &value, 0);
+ /* wsize has a floor of 1 page */
+ if (vol->wsize < PAGE_CACHE_SIZE) {
+ cERROR(1, "minimum wsize is %lu",
+ PAGE_CACHE_SIZE);
+ goto cifs_parse_mount_err;
+ }
}
} else if (strnicmp(data, "sockopt", 5) == 0) {
if (!value || !*value) {
@@ -2292,16 +2304,16 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
(new->mnt_cifs_flags & CIFS_MOUNT_MASK))
return 0;
- if (old->rsize != new->rsize)
- return 0;
-
/*
- * We want to share sb only if we don't specify wsize or specified wsize
- * is greater or equal than existing one.
+ * We want to share sb only if we don't specify an r/wsize or
+ * specified r/wsize is greater than or equal to existing one.
*/
if (new->wsize && new->wsize < old->wsize)
return 0;
+ if (new->rsize && new->rsize < old->rsize)
+ return 0;
+
if (old->mnt_uid != new->mnt_uid || old->mnt_gid != new->mnt_gid)
return 0;
@@ -2739,14 +2751,6 @@ void reset_cifs_unix_caps(int xid, struct cifs_tcon *tcon,
CIFS_MOUNT_POSIX_PATHS;
}
- if (cifs_sb && (cifs_sb->rsize > 127 * 1024)) {
- if ((cap & CIFS_UNIX_LARGE_READ_CAP) == 0) {
- cifs_sb->rsize = 127 * 1024;
- cFYI(DBG2, "larger reads not supported by srv");
- }
- }
-
-
cFYI(1, "Negotiate caps 0x%x", (int)cap);
#ifdef CONFIG_CIFS_DEBUG2
if (cap & CIFS_UNIX_FCNTL_CAP)
@@ -2791,27 +2795,12 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
spin_lock_init(&cifs_sb->tlink_tree_lock);
cifs_sb->tlink_tree = RB_ROOT;
- if (pvolume_info->rsize > CIFSMaxBufSize) {
- cERROR(1, "rsize %d too large, using MaxBufSize",
- pvolume_info->rsize);
- cifs_sb->rsize = CIFSMaxBufSize;
- } else if ((pvolume_info->rsize) &&
- (pvolume_info->rsize <= CIFSMaxBufSize))
- cifs_sb->rsize = pvolume_info->rsize;
- else /* default */
- cifs_sb->rsize = CIFSMaxBufSize;
-
- if (cifs_sb->rsize < 2048) {
- cifs_sb->rsize = 2048;
- /* Windows ME may prefer this */
- cFYI(1, "readsize set to minimum: 2048");
- }
-
/*
- * Temporarily set wsize for matching superblock. If we end up using
+ * Temporarily set r/wsize for matching superblock. If we end up using
* new sb then cifs_negotiate_wsize will later negotiate it downward
* if needed.
*/
+ cifs_sb->rsize = pvolume_info->rsize;
cifs_sb->wsize = pvolume_info->wsize;
cifs_sb->mnt_uid = pvolume_info->linux_uid;
@@ -2879,28 +2868,34 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
/*
* When the server supports very large writes via POSIX extensions, we can
- * allow up to 2^24-1, minus the size of a WRITE_AND_X header, not including
- * the RFC1001 length.
+ * allow up to 2^24-1, minus the size of a READ/WRITE_AND_X header, not
+ * including the RFC1001 length.
*
* Note that this might make for "interesting" allocation problems during
* writeback however as we have to allocate an array of pointers for the
* pages. A 16M write means ~32kb page array with PAGE_CACHE_SIZE == 4096.
+ *
+ * For reads, there is a similar problem as we need to allocate an array
+ * of kvecs to handle the receive.
*/
#define CIFS_MAX_WSIZE ((1<<24) - 1 - sizeof(WRITE_REQ) + 4)
+#define CIFS_MAX_RSIZE ((1<<24) - 1 - sizeof(READ_RSP) + 4)
/*
* When the server doesn't allow large posix writes, only allow a wsize of
* 128k minus the size of the WRITE_AND_X header. That allows for a write up
- * to the maximum size described by RFC1002.
+ * to the maximum size described by RFC1002. Similarly, for reads, we allow
+ * 128 - the size of the READ_AND_X response header.
*/
#define CIFS_MAX_RFC1002_WSIZE (128 * 1024 - sizeof(WRITE_REQ) + 4)
+#define CIFS_MAX_RFC1002_RSIZE (128 * 1024 - sizeof(READ_RSP) + 4)
/*
* The default wsize is 1M. find_get_pages seems to return a maximum of 256
* pages in a single call. With PAGE_CACHE_SIZE == 4k, this means we can fill
* a single wsize request with a single call.
*/
-#define CIFS_DEFAULT_WSIZE (1024 * 1024)
+#define CIFS_DEFAULT_IOSIZE (1024 * 1024)
static unsigned int
cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
@@ -2908,7 +2903,7 @@ cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
struct TCP_Server_Info *server = tcon->ses->server;
unsigned int wsize = pvolume_info->wsize ? pvolume_info->wsize :
- CIFS_DEFAULT_WSIZE;
+ CIFS_DEFAULT_IOSIZE;
/* can server support 24-bit write sizes? (via UNIX extensions) */
if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
@@ -2931,6 +2926,34 @@ cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
return wsize;
}
+static unsigned int
+cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
+{
+ __u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
+ struct TCP_Server_Info *server = tcon->ses->server;
+ unsigned int rsize = pvolume_info->rsize ? pvolume_info->rsize :
+ CIFS_DEFAULT_IOSIZE;
+
+ /* can server support 24-bit write sizes? (via UNIX extensions) */
+ if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_READ_CAP))
+ rsize = min_t(unsigned int, rsize, CIFS_MAX_RFC1002_WSIZE);
+
+ /*
+ * no CAP_LARGE_WRITE_X or is signing enabled without CAP_UNIX set?
+ * Limit it to max buffer offered by the server, minus the size of the
+ * WRITEX header, not including the 4 byte RFC1001 length.
+ */
+ if (!(server->capabilities & CAP_LARGE_READ_X) ||
+ (!(server->capabilities & CAP_UNIX)))
+ rsize = min_t(unsigned int, rsize,
+ server->maxBuf - sizeof(READ_RSP) + 4);
+
+ /* hard limit of CIFS_MAX_RSIZE */
+ rsize = min_t(unsigned int, rsize, CIFS_MAX_RSIZE);
+
+ return rsize;
+}
+
static int
is_path_accessible(int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path)
@@ -3208,14 +3231,8 @@ try_mount_again:
CIFSSMBQFSAttributeInfo(xid, tcon);
}
- if ((tcon->unix_ext == 0) && (cifs_sb->rsize > (1024 * 127))) {
- cifs_sb->rsize = 1024 * 127;
- cFYI(DBG2, "no very large read support, rsize now 127K");
- }
- if (!(tcon->ses->capabilities & CAP_LARGE_READ_X))
- cifs_sb->rsize = min(cifs_sb->rsize, CIFSMaxBufSize);
-
cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info);
+ cifs_sb->rsize = cifs_negotiate_rsize(tcon, volume_info);
remote_path_check:
#ifdef CONFIG_CIFS_DFS_UPCALL
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2f263bd..29c2dac 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1714,6 +1714,7 @@ cifs_iovec_read(struct file *file, const struct iovec *iov,
struct smb_com_read_rsp *pSMBr;
struct cifs_io_parms io_parms;
char *read_data;
+ unsigned int rsize;
__u32 pid;
if (!nr_segs)
@@ -1726,6 +1727,9 @@ cifs_iovec_read(struct file *file, const struct iovec *iov,
xid = GetXid();
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
+ /* FIXME: set up read handler for larger reads or convert to async */
+ rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
+
open_file = file->private_data;
pTcon = tlink_tcon(open_file->tlink);
@@ -1738,7 +1742,7 @@ cifs_iovec_read(struct file *file, const struct iovec *iov,
cFYI(1, "attempting read on write only file instance");
for (total_read = 0; total_read < len; total_read += bytes_read) {
- cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
+ cur_len = min_t(const size_t, len - total_read, rsize);
rc = -EAGAIN;
read_data = NULL;
@@ -1830,6 +1834,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
unsigned int bytes_read = 0;
unsigned int total_read;
unsigned int current_read_size;
+ unsigned int rsize;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *pTcon;
int xid;
@@ -1842,6 +1847,9 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
xid = GetXid();
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
+ /* FIXME: set up read handler for larger reads or convert to async */
+ rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
+
if (file->private_data == NULL) {
rc = -EBADF;
FreeXid(xid);
@@ -1862,7 +1870,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
read_size > total_read;
total_read += bytes_read, current_offset += bytes_read) {
current_read_size = min_t(const int, read_size - total_read,
- cifs_sb->rsize);
+ rsize);
/* For windows me and 9x we do not want to request more
than it negotiated since it will refuse the read then */
if ((pTcon->ses) &&
--
1.7.6
--
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