From bdf1b03e093bdbc571f404e751c7b0e2dca412ea Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 22 Feb 2011 20:17:19 -0500 Subject: [PATCH] cifs: replace /proc/fs/cifs/Experimental with a module parm This flag currently only affects whether we allow "zero-copy" writes with signing enabled. Typically we map pages in the pagecache directly into the write request. If signing is enabled however and the contents of the page change after the signature is calculated but before the write is sent then the signature will be wrong. Servers typically respond to this by closing down the socket. Still, this can provide a performance benefit so the "Experimental" flag was overloaded to allow this. That's really not a good place for this option however since it's not clear what that flag does. Move that flag instead to a new module parameter that better describes its purpose. That's also better since it can be set at module insertion time by configuring modprobe.d. Reviewed-by: Suresh Jayaraman Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/README | 16 ---------------- fs/cifs/cifs_debug.c | 43 ------------------------------------------- fs/cifs/cifsfs.c | 5 ++++- fs/cifs/cifsglob.h | 2 +- fs/cifs/file.c | 4 ++-- 5 files changed, 7 insertions(+), 63 deletions(-) diff --git a/fs/cifs/README b/fs/cifs/README index fe1683590828..74ab165fc646 100644 --- a/fs/cifs/README +++ b/fs/cifs/README @@ -685,22 +685,6 @@ LinuxExtensionsEnabled If set to one then the client will attempt to support and want to map the uid and gid fields to values supplied at mount (rather than the actual values, then set this to zero. (default 1) -Experimental When set to 1 used to enable certain experimental - features (currently enables multipage writes - when signing is enabled, the multipage write - performance enhancement was disabled when - signing turned on in case buffer was modified - just before it was sent, also this flag will - be used to use the new experimental directory change - notification code). When set to 2 enables - an additional experimental feature, "raw ntlmssp" - session establishment support (which allows - specifying "sec=ntlmssp" on mount). The Linux cifs - module will use ntlmv2 authentication encapsulated - in "raw ntlmssp" (not using SPNEGO) when - "sec=ntlmssp" is specified on mount. - This support also requires building cifs with - the CONFIG_CIFS_EXPERIMENTAL configuration flag. These experimental features and tracing can be enabled by changing flags in /proc/fs/cifs (after the cifs module has been installed or built into the diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index 65829d32128c..30d01bc90855 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -423,7 +423,6 @@ static const struct file_operations cifs_lookup_cache_proc_fops; static const struct file_operations traceSMB_proc_fops; static const struct file_operations cifs_multiuser_mount_proc_fops; static const struct file_operations cifs_security_flags_proc_fops; -static const struct file_operations cifs_experimental_proc_fops; static const struct file_operations cifs_linux_ext_proc_fops; void @@ -441,8 +440,6 @@ cifs_proc_init(void) proc_create("cifsFYI", 0, proc_fs_cifs, &cifsFYI_proc_fops); proc_create("traceSMB", 0, proc_fs_cifs, &traceSMB_proc_fops); proc_create("OplockEnabled", 0, proc_fs_cifs, &cifs_oplock_proc_fops); - proc_create("Experimental", 0, proc_fs_cifs, - &cifs_experimental_proc_fops); proc_create("LinuxExtensionsEnabled", 0, proc_fs_cifs, &cifs_linux_ext_proc_fops); proc_create("MultiuserMount", 0, proc_fs_cifs, @@ -469,7 +466,6 @@ cifs_proc_clean(void) remove_proc_entry("OplockEnabled", proc_fs_cifs); remove_proc_entry("SecurityFlags", proc_fs_cifs); remove_proc_entry("LinuxExtensionsEnabled", proc_fs_cifs); - remove_proc_entry("Experimental", proc_fs_cifs); remove_proc_entry("LookupCacheEnabled", proc_fs_cifs); remove_proc_entry("fs/cifs", NULL); } @@ -550,45 +546,6 @@ static const struct file_operations cifs_oplock_proc_fops = { .write = cifs_oplock_proc_write, }; -static int cifs_experimental_proc_show(struct seq_file *m, void *v) -{ - seq_printf(m, "%d\n", experimEnabled); - return 0; -} - -static int cifs_experimental_proc_open(struct inode *inode, struct file *file) -{ - return single_open(file, cifs_experimental_proc_show, NULL); -} - -static ssize_t cifs_experimental_proc_write(struct file *file, - const char __user *buffer, size_t count, loff_t *ppos) -{ - char c; - int rc; - - rc = get_user(c, buffer); - if (rc) - return rc; - if (c == '0' || c == 'n' || c == 'N') - experimEnabled = 0; - else if (c == '1' || c == 'y' || c == 'Y') - experimEnabled = 1; - else if (c == '2') - experimEnabled = 2; - - return count; -} - -static const struct file_operations cifs_experimental_proc_fops = { - .owner = THIS_MODULE, - .open = cifs_experimental_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, - .write = cifs_experimental_proc_write, -}; - static int cifs_linux_ext_proc_show(struct seq_file *m, void *v) { seq_printf(m, "%d\n", linuxExtEnabled); diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index f2970136d17d..41c78e8fc591 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -53,7 +53,6 @@ int cifsFYI = 0; int cifsERROR = 1; int traceSMB = 0; unsigned int oplockEnabled = 1; -unsigned int experimEnabled = 0; unsigned int linuxExtEnabled = 1; unsigned int lookupCacheEnabled = 1; unsigned int multiuser_mount = 0; @@ -82,6 +81,10 @@ module_param(echo_retries, ushort, 0644); MODULE_PARM_DESC(echo_retries, "Number of echo attempts before giving up and " "reconnecting server. Default: 5. 0 means " "never reconnect."); +bool sign_zero_copy; /* globals init to false automatically */ +module_param(sign_zero_copy, bool, 0644); +MODULE_PARM_DESC(sign_zero_copy, "Don't copy pages on write with signing " + "enabled. Default: N"); extern mempool_t *cifs_sm_req_poolp; extern mempool_t *cifs_req_poolp; extern mempool_t *cifs_mid_poolp; diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 17afb0fbcaed..10e4afe54e22 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -817,7 +817,6 @@ GLOBAL_EXTERN unsigned int multiuser_mount; /* if enabled allows new sessions have the uid/password or Kerberos credential or equivalent for current user */ GLOBAL_EXTERN unsigned int oplockEnabled; -GLOBAL_EXTERN unsigned int experimEnabled; GLOBAL_EXTERN unsigned int lookupCacheEnabled; GLOBAL_EXTERN unsigned int global_secflags; /* if on, session setup sent with more secure ntlmssp2 challenge/resp */ @@ -827,6 +826,7 @@ GLOBAL_EXTERN unsigned int CIFSMaxBufSize; /* max size not including hdr */ GLOBAL_EXTERN unsigned int cifs_min_rcv; /* min size of big ntwrk buf pool */ GLOBAL_EXTERN unsigned int cifs_min_small; /* min size of small buf pool */ GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/ +GLOBAL_EXTERN bool sign_zero_copy; /* don't copy written pages with signing */ /* reconnect after this many failed echo attempts */ GLOBAL_EXTERN unsigned short echo_retries; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 5ae061c4ca25..e2d7b6bada6f 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -981,7 +981,7 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file, if (rc != 0) break; } - if (experimEnabled || (pTcon->ses->server && + if (sign_zero_copy || (pTcon->ses->server && ((pTcon->ses->server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) == 0))) { @@ -1242,7 +1242,7 @@ static int cifs_writepages(struct address_space *mapping, } tcon = tlink_tcon(open_file->tlink); - if (!experimEnabled && tcon->ses->server->secMode & + if (!sign_zero_copy && tcon->ses->server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) { cifsFileInfo_put(open_file); kfree(iov); -- 2.20.1