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. Cc: Jeff Layton <[email protected]> Signed-off-by: Suresh Jayaraman <[email protected]> --- fs/cifs/cifs_fs_sb.h | 1 + fs/cifs/cifsfs.c | 1 + fs/cifs/cifsglob.h | 5 +++++ fs/cifs/connect.c | 10 ++++++++++ fs/cifs/inode.c | 6 +++--- 5 files changed, 20 insertions(+), 3 deletions(-) diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index e9a393c..efd2d73 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -48,6 +48,7 @@ struct cifs_sb_info { struct nls_table *local_nls; unsigned int rsize; unsigned int wsize; + unsigned int actimeo; atomic_t active; uid_t mnt_uid; gid_t mnt_gid; diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 9c37897..13be23d 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -461,6 +461,7 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m) seq_printf(s, ",rsize=%d", cifs_sb->rsize); seq_printf(s, ",wsize=%d", cifs_sb->wsize); + seq_printf(s, ",actimeo=%d", cifs_sb->actimeo); return 0; } diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index b577bf0..037f793 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -45,6 +45,11 @@ #define CIFS_MIN_RCV_POOL 4 /* + * default attribute cache timeout (seconds) + */ +#define CIFS_DEF_ACTIMEO (1) + +/* * MAX_REQ is the maximum number of requests that WE will send * on one socket concurrently. It also matches the most common * value of max multiplex returned by servers. We may diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 251a17c..7f92328 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -103,6 +103,7 @@ struct smb_vol { bool multiuser:1; unsigned int rsize; unsigned int wsize; + unsigned int actimeo; /* attribute cache timeout */ bool sockopt_tcp_nodelay:1; unsigned short int port; char *prepath; @@ -1214,6 +1215,10 @@ 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 = + simple_strtoul(value, &value, 0); } else if (strnicmp(data, "credentials", 4) == 0) { /* ignore */ } else if (strnicmp(data, "version", 3) == 0) { @@ -2566,6 +2571,11 @@ 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); + if (pvolume_info->actimeo) + cifs_sb->actimeo = pvolume_info->actimeo; + else /* default */ + cifs_sb->actimeo = CIFS_DEF_ACTIMEO; + if (pvolume_info->noperm) cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_PERM; if (pvolume_info->setuids) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index ff7d299..f30700d 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -1648,6 +1648,7 @@ static bool cifs_inode_needs_reval(struct inode *inode) { struct cifsInodeInfo *cifs_i = CIFS_I(inode); + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); if (cifs_i->clientCanCacheRead) return false; @@ -1658,12 +1659,11 @@ cifs_inode_needs_reval(struct inode *inode) if (cifs_i->time == 0) return true; - /* FIXME: the actimeo should be tunable */ - if (time_after_eq(jiffies, cifs_i->time + HZ)) + if (time_after_eq(jiffies, cifs_i->time + (cifs_sb->actimeo * HZ))) return true; /* hardlinked files w/ noserverino get "special" treatment */ - if (!(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) && + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) && S_ISREG(inode->i_mode) && inode->i_nlink != 1) return true; -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
