diff options
| -rw-r--r-- | fs/cifs/connect.c | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6070ba69647..2e7a79cd2b9 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2647,23 +2647,6 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, else /* default */ cifs_sb->rsize = CIFSMaxBufSize; - if (pvolume_info->wsize > PAGEVEC_SIZE * PAGE_CACHE_SIZE) { - cERROR(1, "wsize %d too large, using 4096 instead", - pvolume_info->wsize); - cifs_sb->wsize = 4096; - } else if (pvolume_info->wsize) - cifs_sb->wsize = pvolume_info->wsize; - else - cifs_sb->wsize = min_t(const int, - PAGEVEC_SIZE * PAGE_CACHE_SIZE, - 127*1024); - /* old default of CIFSMaxBufSize was too small now - that SMB Write2 can send multiple pages in kvec. - RFC1001 does not describe what happens when frame - bigger than 128K is sent so use that as max in - conjunction with 52K kvec constraint on arch with 4K - page size */ - if (cifs_sb->rsize < 2048) { cifs_sb->rsize = 2048; /* Windows ME may prefer this */ @@ -2742,6 +2725,53 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, "mount option supported"); } +/* + * When the server supports very large writes via POSIX extensions, we can + * allow up to 2^24 - PAGE_CACHE_SIZE. + * + * 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. + */ +#define CIFS_MAX_WSIZE ((1<<24) - PAGE_CACHE_SIZE) + +/* + * When the server doesn't allow large posix writes, default to a wsize of + * 128k - PAGE_CACHE_SIZE -- one page less than the largest frame size + * described in RFC1001. This allows space for the header without going over + * that by default. + */ +#define CIFS_MAX_RFC1001_WSIZE (128 * 1024 - PAGE_CACHE_SIZE) + +/* + * 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) + +static unsigned int +cifs_negotiate_wsize(struct cifsTconInfo *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; + + /* can server support 24-bit write sizes? (via UNIX extensions) */ + if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP)) + wsize = min_t(unsigned int, wsize, CIFS_MAX_RFC1001_WSIZE); + + /* no CAP_LARGE_WRITE_X? Limit it to 16 bits */ + if (!(server->capabilities & CAP_LARGE_WRITE_X)) + wsize = min_t(unsigned int, wsize, USHRT_MAX); + + /* hard limit of CIFS_MAX_WSIZE */ + wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE); + + return wsize; +} + static int is_path_accessible(int xid, struct cifsTconInfo *tcon, struct cifs_sb_info *cifs_sb, const char *full_path) @@ -3014,13 +3044,12 @@ try_mount_again: cifs_sb->rsize = 1024 * 127; cFYI(DBG2, "no very large read support, rsize now 127K"); } - if (!(tcon->ses->capabilities & CAP_LARGE_WRITE_X)) - cifs_sb->wsize = min(cifs_sb->wsize, - (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)); if (!(tcon->ses->capabilities & CAP_LARGE_READ_X)) cifs_sb->rsize = min(cifs_sb->rsize, (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)); + cifs_sb->wsize = cifs_negotiate_wsize(tcon, volume_info); + remote_path_check: #ifdef CONFIG_CIFS_DFS_UPCALL /* |