From 413e661c136c52290de1ee19a1b049a4da9dbf51 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 28 Oct 2010 13:33:38 -0400 Subject: cifs: store pointer to master tlink in superblock (try #2) This is the second version of this patch, the only difference between it and the first one is that this explicitly makes cifs_sb_master_tlink a static inline. Instead of keeping a tag on the master tlink in the tree, just keep a pointer to the master in the superblock. That eliminates the need for using the radix tree to look up a tagged entry. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 20 ++++---------------- 1 file changed, 4 insertions(+), 16 deletions(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 9eb327defa1d..197ac579a70b 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2914,11 +2914,11 @@ remote_path_check: spin_lock(&cifs_sb->tlink_tree_lock); radix_tree_insert(&cifs_sb->tlink_tree, pSesInfo->linux_uid, tlink); - radix_tree_tag_set(&cifs_sb->tlink_tree, pSesInfo->linux_uid, - CIFS_TLINK_MASTER_TAG); spin_unlock(&cifs_sb->tlink_tree_lock); radix_tree_preload_end(); + cifs_sb->master_tlink = tlink; + queue_delayed_work(system_nrt_wq, &cifs_sb->prune_tlinks, TLINK_IDLE_EXPIRE); @@ -3271,22 +3271,10 @@ out: return tcon; } -static struct tcon_link * +static inline struct tcon_link * cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb) { - struct tcon_link *tlink; - unsigned int ret; - - spin_lock(&cifs_sb->tlink_tree_lock); - ret = radix_tree_gang_lookup_tag(&cifs_sb->tlink_tree, (void **)&tlink, - 0, 1, CIFS_TLINK_MASTER_TAG); - spin_unlock(&cifs_sb->tlink_tree_lock); - - /* the master tcon should always be present */ - if (ret == 0) - BUG(); - - return tlink; + return cifs_sb->master_tlink; } struct cifsTconInfo * -- cgit v1.2.2 From b647c35f77af9c07d336247b23014596e9f0a593 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 28 Oct 2010 11:16:44 -0400 Subject: cifs: convert tlink_tree to a rbtree Radix trees are ideal when you want to track a bunch of pointers and can't embed a tracking structure within the target of those pointers. The tradeoff is an increase in memory, particularly if the tree is sparse. In CIFS, we use the tlink_tree to track tcon_link structs. A tcon_link can never be in more than one tlink_tree, so there's no impediment to using a rb_tree here instead of a radix tree. Convert the new multiuser mount code to use a rb_tree instead. This should reduce the memory required to manage the tlink_tree. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 177 +++++++++++++++++++++++++++++------------------------- 1 file changed, 96 insertions(+), 81 deletions(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 197ac579a70b..c9699ce767b6 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -116,6 +116,7 @@ struct smb_vol { static int ipv4_connect(struct TCP_Server_Info *server); static int ipv6_connect(struct TCP_Server_Info *server); +static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink); static void cifs_prune_tlinks(struct work_struct *work); /* @@ -2900,24 +2901,16 @@ remote_path_check: goto mount_fail_check; } - tlink->tl_index = pSesInfo->linux_uid; + tlink->tl_uid = pSesInfo->linux_uid; tlink->tl_tcon = tcon; tlink->tl_time = jiffies; set_bit(TCON_LINK_MASTER, &tlink->tl_flags); set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); - rc = radix_tree_preload(GFP_KERNEL); - if (rc == -ENOMEM) { - kfree(tlink); - goto mount_fail_check; - } - + cifs_sb->master_tlink = tlink; spin_lock(&cifs_sb->tlink_tree_lock); - radix_tree_insert(&cifs_sb->tlink_tree, pSesInfo->linux_uid, tlink); + tlink_rb_insert(&cifs_sb->tlink_tree, tlink); spin_unlock(&cifs_sb->tlink_tree_lock); - radix_tree_preload_end(); - - cifs_sb->master_tlink = tlink; queue_delayed_work(system_nrt_wq, &cifs_sb->prune_tlinks, TLINK_IDLE_EXPIRE); @@ -3107,32 +3100,25 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses, int cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb) { - int i, ret; + struct rb_root *root = &cifs_sb->tlink_tree; + struct rb_node *node; + struct tcon_link *tlink; char *tmp; - struct tcon_link *tlink[8]; - unsigned long index = 0; cancel_delayed_work_sync(&cifs_sb->prune_tlinks); - do { - spin_lock(&cifs_sb->tlink_tree_lock); - ret = radix_tree_gang_lookup(&cifs_sb->tlink_tree, - (void **)tlink, index, - ARRAY_SIZE(tlink)); - /* increment index for next pass */ - if (ret > 0) - index = tlink[ret - 1]->tl_index + 1; - for (i = 0; i < ret; i++) { - cifs_get_tlink(tlink[i]); - clear_bit(TCON_LINK_IN_TREE, &tlink[i]->tl_flags); - radix_tree_delete(&cifs_sb->tlink_tree, - tlink[i]->tl_index); - } - spin_unlock(&cifs_sb->tlink_tree_lock); + spin_lock(&cifs_sb->tlink_tree_lock); + while ((node = rb_first(root))) { + tlink = rb_entry(node, struct tcon_link, tl_rbnode); + cifs_get_tlink(tlink); + clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); + rb_erase(node, root); - for (i = 0; i < ret; i++) - cifs_put_tlink(tlink[i]); - } while (ret != 0); + spin_unlock(&cifs_sb->tlink_tree_lock); + cifs_put_tlink(tlink); + spin_lock(&cifs_sb->tlink_tree_lock); + } + spin_unlock(&cifs_sb->tlink_tree_lock); tmp = cifs_sb->prepath; cifs_sb->prepathlen = 0; @@ -3290,6 +3276,47 @@ cifs_sb_tcon_pending_wait(void *unused) return signal_pending(current) ? -ERESTARTSYS : 0; } +/* find and return a tlink with given uid */ +static struct tcon_link * +tlink_rb_search(struct rb_root *root, uid_t uid) +{ + struct rb_node *node = root->rb_node; + struct tcon_link *tlink; + + while (node) { + tlink = rb_entry(node, struct tcon_link, tl_rbnode); + + if (tlink->tl_uid > uid) + node = node->rb_left; + else if (tlink->tl_uid < uid) + node = node->rb_right; + else + return tlink; + } + return NULL; +} + +/* insert a tcon_link into the tree */ +static void +tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink) +{ + struct rb_node **new = &(root->rb_node), *parent = NULL; + struct tcon_link *tlink; + + while (*new) { + tlink = rb_entry(*new, struct tcon_link, tl_rbnode); + parent = *new; + + if (tlink->tl_uid > new_tlink->tl_uid) + new = &((*new)->rb_left); + else + new = &((*new)->rb_right); + } + + rb_link_node(&new_tlink->tl_rbnode, parent, new); + rb_insert_color(&new_tlink->tl_rbnode, root); +} + /* * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the * current task. @@ -3310,14 +3337,14 @@ struct tcon_link * cifs_sb_tlink(struct cifs_sb_info *cifs_sb) { int ret; - unsigned long fsuid = (unsigned long) current_fsuid(); + uid_t fsuid = current_fsuid(); struct tcon_link *tlink, *newtlink; if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb)); spin_lock(&cifs_sb->tlink_tree_lock); - tlink = radix_tree_lookup(&cifs_sb->tlink_tree, fsuid); + tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid); if (tlink) cifs_get_tlink(tlink); spin_unlock(&cifs_sb->tlink_tree_lock); @@ -3326,36 +3353,24 @@ cifs_sb_tlink(struct cifs_sb_info *cifs_sb) newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL); if (newtlink == NULL) return ERR_PTR(-ENOMEM); - newtlink->tl_index = fsuid; + newtlink->tl_uid = fsuid; newtlink->tl_tcon = ERR_PTR(-EACCES); set_bit(TCON_LINK_PENDING, &newtlink->tl_flags); set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags); cifs_get_tlink(newtlink); - ret = radix_tree_preload(GFP_KERNEL); - if (ret != 0) { - kfree(newtlink); - return ERR_PTR(ret); - } - spin_lock(&cifs_sb->tlink_tree_lock); /* was one inserted after previous search? */ - tlink = radix_tree_lookup(&cifs_sb->tlink_tree, fsuid); + tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid); if (tlink) { cifs_get_tlink(tlink); spin_unlock(&cifs_sb->tlink_tree_lock); - radix_tree_preload_end(); kfree(newtlink); goto wait_for_construction; } - ret = radix_tree_insert(&cifs_sb->tlink_tree, fsuid, newtlink); - spin_unlock(&cifs_sb->tlink_tree_lock); - radix_tree_preload_end(); - if (ret) { - kfree(newtlink); - return ERR_PTR(ret); - } tlink = newtlink; + tlink_rb_insert(&cifs_sb->tlink_tree, tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); } else { wait_for_construction: ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING, @@ -3401,39 +3416,39 @@ cifs_prune_tlinks(struct work_struct *work) { struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info, prune_tlinks.work); - struct tcon_link *tlink[8]; - unsigned long now = jiffies; - unsigned long index = 0; - int i, ret; + struct rb_root *root = &cifs_sb->tlink_tree; + struct rb_node *node = rb_first(root); + struct rb_node *tmp; + struct tcon_link *tlink; - do { - spin_lock(&cifs_sb->tlink_tree_lock); - ret = radix_tree_gang_lookup(&cifs_sb->tlink_tree, - (void **)tlink, index, - ARRAY_SIZE(tlink)); - /* increment index for next pass */ - if (ret > 0) - index = tlink[ret - 1]->tl_index + 1; - for (i = 0; i < ret; i++) { - if (test_bit(TCON_LINK_MASTER, &tlink[i]->tl_flags) || - atomic_read(&tlink[i]->tl_count) != 0 || - time_after(tlink[i]->tl_time + TLINK_IDLE_EXPIRE, - now)) { - tlink[i] = NULL; - continue; - } - cifs_get_tlink(tlink[i]); - clear_bit(TCON_LINK_IN_TREE, &tlink[i]->tl_flags); - radix_tree_delete(&cifs_sb->tlink_tree, - tlink[i]->tl_index); - } - spin_unlock(&cifs_sb->tlink_tree_lock); + /* + * Because we drop the spinlock in the loop in order to put the tlink + * it's not guarded against removal of links from the tree. The only + * places that remove entries from the tree are this function and + * umounts. Because this function is non-reentrant and is canceled + * before umount can proceed, this is safe. + */ + spin_lock(&cifs_sb->tlink_tree_lock); + node = rb_first(root); + while (node != NULL) { + tmp = node; + node = rb_next(tmp); + tlink = rb_entry(tmp, struct tcon_link, tl_rbnode); + + if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) || + atomic_read(&tlink->tl_count) != 0 || + time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies)) + continue; - for (i = 0; i < ret; i++) { - if (tlink[i] != NULL) - cifs_put_tlink(tlink[i]); - } - } while (ret != 0); + cifs_get_tlink(tlink); + clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); + rb_erase(tmp, root); + + spin_unlock(&cifs_sb->tlink_tree_lock); + cifs_put_tlink(tlink); + spin_lock(&cifs_sb->tlink_tree_lock); + } + spin_unlock(&cifs_sb->tlink_tree_lock); queue_delayed_work(system_nrt_wq, &cifs_sb->prune_tlinks, TLINK_IDLE_EXPIRE); -- cgit v1.2.2 From 6ef933a38ade555a175ecab9d803e6bb73399763 Mon Sep 17 00:00:00 2001 From: Suresh Jayaraman Date: Wed, 3 Nov 2010 10:53:49 +0530 Subject: cifs: trivial comment fix: tlink_tree is now a rbtree Noticed while reviewing (late) the rbtree conversion patchset (which has been merged already). Cc: Jeff Layton Signed-off-by: Suresh Jayaraman Signed-off-by: Steve French --- fs/cifs/connect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index c9699ce767b6..251a17c03545 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3324,7 +3324,7 @@ tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink) * If the superblock doesn't refer to a multiuser mount, then just return * the master tcon for the mount. * - * First, search the radix tree for an existing tcon for this fsuid. If one + * First, search the rbtree for an existing tcon for this fsuid. If one * exists, then check to see if it's pending construction. If it is then wait * for construction to complete. Once it's no longer pending, check to see if * it failed and either return an error or retry construction, depending on -- cgit v1.2.2 From 607a569da4cf289fd8eb3887080ed3b212e3112d Mon Sep 17 00:00:00 2001 From: Suresh Jayaraman Date: Wed, 24 Nov 2010 17:49:05 +0530 Subject: cifs: allow fsc mount option only if CONFIG_CIFS_FSCACHE is set Currently, it is possible to specify 'fsc' mount option even if CONFIG_CIFS_FSCACHE has not been set. The option is being ignored silently while the user fscache functionality to work. Fix this by raising error when the CONFIG option is not set. Reported-by: Jeff Layton Reviewed-by: Jeff Layton Signed-off-by: Suresh Jayaraman Signed-off-by: Steve French --- fs/cifs/connect.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 251a17c03545..32fa4d9b5dbc 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1352,6 +1352,11 @@ cifs_parse_mount_options(char *options, const char *devname, "supported. Instead set " "/proc/fs/cifs/LookupCacheEnabled to 0\n"); } else if (strnicmp(data, "fsc", 3) == 0) { +#ifndef CONFIG_CIFS_FSCACHE + cERROR(1, "FS-Cache support needs CONFIG_CIFS_FSCACHE" + "kernel config option set"); + return 1; +#endif vol->fsc = true; } else if (strnicmp(data, "mfsymlinks", 10) == 0) { vol->mfsymlinks = true; -- cgit v1.2.2 From 6d20e8406f0942228a73000663c2b33f488103ea Mon Sep 17 00:00:00 2001 From: Suresh Jayaraman Date: Wed, 1 Dec 2010 14:42:28 +0530 Subject: cifs: add attribute cache timeout (actimeo) tunable Currently, the attribute cache timeout for CIFS is hardcoded to 1 second. This means that the client might have to issue a QPATHINFO/QFILEINFO call every 1 second to verify if something has changes, which seems too expensive. On the other hand, if the timeout is hardcoded to a higher value, workloads that expect strict cache coherency might see unexpected results. Making attribute cache timeout as a tunable will allow us to make a tradeoff between performance and cache metadata correctness depending on the application/workload needs. Add 'actimeo' tunable that can be used to tune the attribute cache timeout. The default timeout is set to 1 second. Also, display actimeo option value in /proc/mounts. It appears to me that 'actimeo' and the proposed (but not yet merged) 'strictcache' option cannot coexist, so care must be taken that we reset the other option if one of them is set. Changes since last post: - fix option parsing and handle possible values correcly Reviewed-by: Jeff Layton Signed-off-by: Suresh Jayaraman Signed-off-by: Steve French --- fs/cifs/connect.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 32fa4d9b5dbc..bb17ee2ba782 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -105,6 +105,7 @@ struct smb_vol { unsigned int wsize; bool sockopt_tcp_nodelay:1; unsigned short int port; + unsigned long actimeo; /* attribute cache timeout (jiffies) */ char *prepath; struct sockaddr_storage srcaddr; /* allow binding to a local IP */ struct nls_table *local_nls; @@ -840,6 +841,8 @@ cifs_parse_mount_options(char *options, const char *devname, /* default to using server inode numbers where available */ vol->server_ino = 1; + vol->actimeo = CIFS_DEF_ACTIMEO; + if (!options) return 1; @@ -1214,6 +1217,16 @@ cifs_parse_mount_options(char *options, const char *devname, printk(KERN_WARNING "CIFS: server net" "biosname longer than 15 truncated.\n"); } + } else if (strnicmp(data, "actimeo", 7) == 0) { + if (value && *value) { + vol->actimeo = HZ * simple_strtoul(value, + &value, 0); + if (vol->actimeo > CIFS_MAX_ACTIMEO) { + cERROR(1, "CIFS: attribute cache" + "timeout too large"); + return 1; + } + } } else if (strnicmp(data, "credentials", 4) == 0) { /* ignore */ } else if (strnicmp(data, "version", 3) == 0) { @@ -2571,6 +2584,8 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info, cFYI(1, "file mode: 0x%x dir mode: 0x%x", cifs_sb->mnt_file_mode, cifs_sb->mnt_dir_mode); + cifs_sb->actimeo = pvolume_info->actimeo; + if (pvolume_info->noperm) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_PERM; if (pvolume_info->setuids) -- cgit v1.2.2 From 884639996814585ef7079daa9e03a1eb562e235c Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 22 Nov 2010 15:31:03 -0500 Subject: cifs: remove Local_System_Name ...this string is zeroed out and nothing ever changes it. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index bb17ee2ba782..53f9c31a52b2 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -807,23 +807,20 @@ cifs_parse_mount_options(char *options, const char *devname, short int override_gid = -1; bool uid_specified = false; bool gid_specified = false; + char *nodename = utsname()->nodename; separator[0] = ','; separator[1] = 0; - if (Local_System_Name[0] != 0) - memcpy(vol->source_rfc1001_name, Local_System_Name, 15); - else { - char *nodename = utsname()->nodename; - int n = strnlen(nodename, 15); - memset(vol->source_rfc1001_name, 0x20, 15); - for (i = 0; i < n; i++) { - /* does not have to be perfect mapping since field is - informational, only used for servers that do not support - port 445 and it can be overridden at mount time */ - vol->source_rfc1001_name[i] = toupper(nodename[i]); - } - } + /* + * does not have to be perfect mapping since field is + * informational, only used for servers that do not support + * port 445 and it can be overridden at mount time + */ + memset(vol->source_rfc1001_name, 0x20, 15); + for (i = 0; i < strnlen(nodename, 15); i++) + vol->source_rfc1001_name[i] = toupper(nodename[i]); + vol->source_rfc1001_name[15] = 0; /* null target name indicates to use *SMBSERVR default called name if we end up sending RFC1001 session initialize */ -- cgit v1.2.2 From 03ceace5c6923ffbcf2b4d2e37afbffbdb5d4a67 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 6 Dec 2010 21:07:33 -0500 Subject: cifs: fix check of error return from is_path_accessable This function will return 0 if everything went ok. Commit 9d002df4 however added a block of code after the following check for rc == -EREMOTE. With that change and when rc == 0, doing the "goto mount_fail_check" here skips that code, leaving the tlink_tree and master_tlink pointer unpopulated. That causes an oops later in cifs_root_iget. Reported-and-Tested-by: Robbert Kouprie Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 53f9c31a52b2..387b91ae7400 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2839,7 +2839,7 @@ remote_path_check: goto mount_fail_check; } rc = is_path_accessible(xid, tcon, cifs_sb, full_path); - if (rc != -EREMOTE) { + if (rc != 0 && rc != -EREMOTE) { kfree(full_path); goto mount_fail_check; } -- cgit v1.2.2 From 7d161b7f41e24203b54b0f18ae0d26c18a6c6fab Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 7 Dec 2010 02:10:35 -0500 Subject: cifs: allow calling cifs_build_path_to_root on incomplete cifs_sb It's possible that cifs_mount will call cifs_build_path_to_root on a newly instantiated cifs_sb. In that case, it's likely that the master_tlink pointer has not yet been instantiated. Fix this by having cifs_build_path_to_root take a cifsTconInfo pointer as well, and have the caller pass that in. Reported-and-Tested-by: Robbert Kouprie Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 387b91ae7400..cc1a8604a790 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2833,7 +2833,7 @@ remote_path_check: /* check if a whole path (including prepath) is not remote */ if (!rc && cifs_sb->prepathlen && tcon) { /* build_path_to_root works only when we have a valid tcon */ - full_path = cifs_build_path_to_root(cifs_sb); + full_path = cifs_build_path_to_root(cifs_sb, tcon); if (full_path == NULL) { rc = -ENOMEM; goto mount_fail_check; -- cgit v1.2.2