From 870a5be8b92151332da65021b7b21104e9c1de07 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 5 Oct 2008 12:07:23 -0400 Subject: NFS: Clean up nfs_refresh_inode() and nfs_post_op_update_inode() Try to avoid taking and dropping the inode->i_lock more than once. Do so by moving the code in nfs_refresh_inode() that needs to be done under the spinlock into a function nfs_refresh_inode_locked(), and then having both nfs_refresh_inode() and nfs_post_op_update_inode() call it directly. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 52daefa2f521..f189169348b1 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -948,6 +948,15 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat return 0; } +static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + if (time_after(fattr->time_start, nfsi->last_updated)) + return nfs_update_inode(inode, fattr); + return nfs_check_inode_attributes(inode, fattr); +} + /** * nfs_refresh_inode - try to update the inode attribute cache * @inode - pointer to inode @@ -960,17 +969,12 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat */ int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) { - struct nfs_inode *nfsi = NFS_I(inode); int status; if ((fattr->valid & NFS_ATTR_FATTR) == 0) return 0; spin_lock(&inode->i_lock); - if (time_after(fattr->time_start, nfsi->last_updated)) - status = nfs_update_inode(inode, fattr); - else - status = nfs_check_inode_attributes(inode, fattr); - + status = nfs_refresh_inode_locked(inode, fattr); spin_unlock(&inode->i_lock); return status; } @@ -992,13 +996,16 @@ int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr) { struct nfs_inode *nfsi = NFS_I(inode); + int status = 0; spin_lock(&inode->i_lock); nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE; if (S_ISDIR(inode->i_mode)) nfsi->cache_validity |= NFS_INO_INVALID_DATA; + if ((fattr->valid & NFS_ATTR_FATTR) != 0) + status = nfs_refresh_inode_locked(inode, fattr); spin_unlock(&inode->i_lock); - return nfs_refresh_inode(inode, fattr); + return status; } /** -- cgit v1.2.1 From a10ad17630024bf7aae8e7f18352f816ee483091 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 23 Sep 2008 17:28:41 -0400 Subject: NFS: Fix the NFS attribute update Currently nfs_refresh_inode() will only update the inode metadata if it sees that the RPC call that returned the nfs_fattr was started after the last update of the inode. This means that if we have parallel RPC calls to the same inode (when sending WRITE calls, for instance), we may often miss updates. This patch attempts to recover those missed updates by also accepting them if the ctime in the nfs_fattr is more recent than the inode's cached ctime. It also recovers the case where the file size has increased, but the ctime has not been updated due to limited ctime resolution. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index f189169348b1..8c514a1353c0 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -948,11 +948,49 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat return 0; } -static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) +static int nfs_ctime_need_update(const struct inode *inode, const struct nfs_fattr *fattr) { - struct nfs_inode *nfsi = NFS_I(inode); + return timespec_compare(&fattr->ctime, &inode->i_ctime) > 0; +} + +static int nfs_size_need_update(const struct inode *inode, const struct nfs_fattr *fattr) +{ + return nfs_size_to_loff_t(fattr->size) > i_size_read(inode); +} - if (time_after(fattr->time_start, nfsi->last_updated)) +/** + * nfs_inode_attrs_need_update - check if the inode attributes need updating + * @inode - pointer to inode + * @fattr - attributes + * + * Attempt to divine whether or not an RPC call reply carrying stale + * attributes got scheduled after another call carrying updated ones. + * + * To do so, the function first assumes that a more recent ctime means + * that the attributes in fattr are newer, however it also attempt to + * catch the case where ctime either didn't change, or went backwards + * (if someone reset the clock on the server) by looking at whether + * or not this RPC call was started after the inode was last updated. + * Note also the check for jiffy wraparound if the last_updated timestamp + * is later than 'jiffies'. + * + * The function returns 'true' if it thinks the attributes in 'fattr' are + * more recent than the ones cached in the inode. + * + */ +static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr) +{ + const struct nfs_inode *nfsi = NFS_I(inode); + + return nfs_ctime_need_update(inode, fattr) || + nfs_size_need_update(inode, fattr) || + time_after(fattr->time_start, nfsi->last_updated) || + time_after(nfsi->last_updated, jiffies); +} + +static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) +{ + if (nfs_inode_attrs_need_update(inode, fattr)) return nfs_update_inode(inode, fattr); return nfs_check_inode_attributes(inode, fattr); } -- cgit v1.2.1 From d65f557f39448c2d9e58cd564037b81e646aed2c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 5 Oct 2008 12:27:55 -0400 Subject: NFS: Fix nfs_post_op_update_inode_force_wcc() If we believe that the attributes are old (see nfs_refresh_inode()), then we shouldn't force an update. Also ensure that we hold the inode->i_lock across attribute checks and the call to nfs_refresh_inode_locked() to ensure that we don't race with other attribute updates. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 8c514a1353c0..610d022fc7a5 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1017,6 +1017,18 @@ int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) return status; } +static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr) +{ + struct nfs_inode *nfsi = NFS_I(inode); + + nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE; + if (S_ISDIR(inode->i_mode)) + nfsi->cache_validity |= NFS_INO_INVALID_DATA; + if ((fattr->valid & NFS_ATTR_FATTR) == 0) + return 0; + return nfs_refresh_inode_locked(inode, fattr); +} + /** * nfs_post_op_update_inode - try to update the inode attribute cache * @inode - pointer to inode @@ -1033,15 +1045,10 @@ int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr) */ int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr) { - struct nfs_inode *nfsi = NFS_I(inode); - int status = 0; + int status; spin_lock(&inode->i_lock); - nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE; - if (S_ISDIR(inode->i_mode)) - nfsi->cache_validity |= NFS_INO_INVALID_DATA; - if ((fattr->valid & NFS_ATTR_FATTR) != 0) - status = nfs_refresh_inode_locked(inode, fattr); + status = nfs_post_op_update_inode_locked(inode, fattr); spin_unlock(&inode->i_lock); return status; } @@ -1059,6 +1066,15 @@ int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr) */ int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr) { + int status; + + spin_lock(&inode->i_lock); + /* Don't do a WCC update if these attributes are already stale */ + if ((fattr->valid & NFS_ATTR_FATTR) == 0 || + !nfs_inode_attrs_need_update(inode, fattr)) { + fattr->valid &= ~(NFS_ATTR_WCC_V4|NFS_ATTR_WCC); + goto out_noforce; + } if ((fattr->valid & NFS_ATTR_FATTR_V4) != 0 && (fattr->valid & NFS_ATTR_WCC_V4) == 0) { fattr->pre_change_attr = NFS_I(inode)->change_attr; @@ -1071,7 +1087,10 @@ int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fa fattr->pre_size = i_size_read(inode); fattr->valid |= NFS_ATTR_WCC; } - return nfs_post_op_update_inode(inode, fattr); +out_noforce: + status = nfs_post_op_update_inode_locked(inode, fattr); + spin_unlock(&inode->i_lock); + return status; } /* -- cgit v1.2.1 From 4dc05efb86239321d43a9d74fd2ecd5c21bfc2ad Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 23 Sep 2008 17:28:42 -0400 Subject: NFS: Convert __nfs_revalidate_inode() to use nfs_refresh_inode() In the case where there are parallel RPC calls to the same inode, we may receive stale metadata due to the lack of ordering, hence the sanity checking of metadata in nfs_refresh_inode(). Currently, __nfs_revalidate_inode() is calling nfs_update_inode() directly, without any further sanity checks, and hence may end up setting the inode up with stale metadata. Fix is to use nfs_refresh_inode() instead of nfs_update_inode(). Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 610d022fc7a5..697157c1fdd1 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -724,16 +724,13 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) goto out; } - spin_lock(&inode->i_lock); - status = nfs_update_inode(inode, &fattr); + status = nfs_refresh_inode(inode, &fattr); if (status) { - spin_unlock(&inode->i_lock); dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n", inode->i_sb->s_id, (long long)NFS_FILEID(inode), status); goto out; } - spin_unlock(&inode->i_lock); if (nfsi->cache_validity & NFS_INO_INVALID_ACL) nfs_zap_acl_cache(inode); -- cgit v1.2.1 From 076f1fc94c44be2664172c63b4a2b51ae2d265ea Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 5 Oct 2008 13:31:21 -0400 Subject: NFS: Don't clear nfsi->cache_validity in nfs_check_inode_attributes() If we're merely checking the inode attributes because we suspect that the 'updated' attributes returned by the RPC call are stale, then we shouldn't be doing weak cache consistency updates or clearing the cache_validity flags. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 697157c1fdd1..a2f54154d825 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -905,9 +905,6 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat return -EIO; } - /* Do atomic weak cache consistency updates */ - nfs_wcc_update_inode(inode, fattr); - if ((fattr->valid & NFS_ATTR_FATTR_V4) != 0 && nfsi->change_attr != fattr->change_attr) invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE; @@ -936,10 +933,6 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat if (invalid != 0) nfsi->cache_validity |= invalid; - else - nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR - | NFS_INO_INVALID_ATIME - | NFS_INO_REVAL_PAGECACHE); nfsi->read_cache_jiffies = fattr->time_start; return 0; -- cgit v1.2.1 From 2f28ea614ff497202d5a52af82da523ae4a20718 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 5 Oct 2008 14:26:11 -0400 Subject: NFS: Fix up nfs_setattr_update_inode() Ensure that it sets the inode metadata under the correct spinlock. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index a2f54154d825..f3b8ed904df7 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -453,6 +453,7 @@ out_big: void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) { if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) { + spin_lock(&inode->i_lock); if ((attr->ia_valid & ATTR_MODE) != 0) { int mode = attr->ia_mode & S_IALLUGO; mode |= inode->i_mode & ~S_IALLUGO; @@ -462,7 +463,6 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) inode->i_uid = attr->ia_uid; if ((attr->ia_valid & ATTR_GID) != 0) inode->i_gid = attr->ia_gid; - spin_lock(&inode->i_lock); NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; spin_unlock(&inode->i_lock); } -- cgit v1.2.1 From 691beb13cdc88358334ef0ba867c080a247a760f Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 5 Oct 2008 14:48:22 -0400 Subject: NFS: Allow concurrent inode revalidation Currently, if two processes are both trying to revalidate metadata for the same inode, they will find themselves being serialised. There is no good justification for this now that we have improved our ability to detect stale attribute data, so we should remove that serialisation. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 43 ++----------------------------------------- 1 file changed, 2 insertions(+), 41 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index f3b8ed904df7..e25009f35cc2 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -472,37 +472,6 @@ void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr) } } -static int nfs_wait_schedule(void *word) -{ - if (signal_pending(current)) - return -ERESTARTSYS; - schedule(); - return 0; -} - -/* - * Wait for the inode to get unlocked. - */ -static int nfs_wait_on_inode(struct inode *inode) -{ - struct nfs_inode *nfsi = NFS_I(inode); - int error; - - error = wait_on_bit_lock(&nfsi->flags, NFS_INO_REVALIDATING, - nfs_wait_schedule, TASK_KILLABLE); - - return error; -} - -static void nfs_wake_up_inode(struct inode *inode) -{ - struct nfs_inode *nfsi = NFS_I(inode); - - clear_bit(NFS_INO_REVALIDATING, &nfsi->flags); - smp_mb__after_clear_bit(); - wake_up_bit(&nfsi->flags, NFS_INO_REVALIDATING); -} - int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; @@ -697,20 +666,15 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n", inode->i_sb->s_id, (long long)NFS_FILEID(inode)); - nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE); if (is_bad_inode(inode)) - goto out_nowait; + goto out; if (NFS_STALE(inode)) - goto out_nowait; - - status = nfs_wait_on_inode(inode); - if (status < 0) goto out; - status = -ESTALE; if (NFS_STALE(inode)) goto out; + nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE); status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), &fattr); if (status != 0) { dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n", @@ -740,9 +704,6 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) (long long)NFS_FILEID(inode)); out: - nfs_wake_up_inode(inode); - - out_nowait: return status; } -- cgit v1.2.1 From 03254e65a60d3113164672dbbadc023c4a56ecd1 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 9 Oct 2008 13:27:55 -0400 Subject: NFS: Fix attribute updates This fixes a regression seen when running the Connectathon testsuite against an ext3 filesystem. The reason was that the inode was constantly being marked as 'just updated' by the jiffy wraparound test. This again meant that newer GETATTR calls were failing to pass the nfs_inode_attrs_need_update() test unless the changes caused a ctime update on the server, since they were perceived as having been started before the latest inode update. Given that nfs_inode_attrs_need_update() already checks for wraparound of nfsi->last_updated, we can drop the buggy "protection" in nfs_update_inode(). Also make a slight micro-optimisation of nfs_inode_attrs_need_update(): we are more often going to see time_after(fattr->time_start, nfsi->last_updated) be true, rather than seeing an update of ctime/size, so put that test first to ensure that we optimise away the ctime/size tests. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index e25009f35cc2..6554281e24a2 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -933,10 +933,10 @@ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct n { const struct nfs_inode *nfsi = NFS_I(inode); - return nfs_ctime_need_update(inode, fattr) || - nfs_size_need_update(inode, fattr) || - time_after(fattr->time_start, nfsi->last_updated) || - time_after(nfsi->last_updated, jiffies); + return time_after(fattr->time_start, nfsi->last_updated) || + nfs_ctime_need_update(inode, fattr) || + nfs_size_need_update(inode, fattr) || + time_after(nfsi->last_updated, jiffies); } static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) @@ -1167,11 +1167,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode); nfsi->attrtimeo_timestamp = now; } - /* - * Avoid jiffy wraparound issues with nfsi->last_updated - */ - if (!time_in_range(nfsi->last_updated, nfsi->read_cache_jiffies, now)) - nfsi->last_updated = nfsi->read_cache_jiffies; } invalid &= ~NFS_INO_INVALID_ATTR; /* Don't invalidate the data if we were to blame */ -- cgit v1.2.1 From 921615f111108258820226a3258a047d9bf1d96a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 14 Oct 2008 19:23:07 -0400 Subject: NFS: Changes to inode->i_nlinks must set the NFS_INO_INVALID_ATTR flag Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 6554281e24a2..de3f11e6234e 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1141,6 +1141,9 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) inode->i_gid != fattr->gid) invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; + if (inode->i_nlink != fattr->nlink) + invalid |= NFS_INO_INVALID_ATTR; + inode->i_mode = fattr->mode; inode->i_nlink = fattr->nlink; inode->i_uid = fattr->uid; -- cgit v1.2.1 From 4704f0e274829e3af00737d2d9adace2d71a9605 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 14 Oct 2008 19:16:07 -0400 Subject: NFS: Fix the resolution problem with nfs_inode_attrs_need_update() It appears that 'jiffies' timestamps do not have high enough resolution for nfs_inode_attrs_need_update(). One problem is that a GETATTR can be launched within < 1 jiffy of the last operation that updated the attribute. Another problem is that RPC calls can take < 1 jiffy to execute. We can fix this by switching the variables to use a simple global counter that gets incremented every time we start another GETATTR call. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 37 ++++++++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 7 deletions(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index de3f11e6234e..116a3bd2bc9b 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -305,7 +305,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) init_special_inode(inode, inode->i_mode, fattr->rdev); nfsi->read_cache_jiffies = fattr->time_start; - nfsi->last_updated = now; + nfsi->attr_gencount = fattr->gencount; nfsi->cache_change_attribute = now; inode->i_atime = fattr->atime; inode->i_mtime = fattr->mtime; @@ -909,6 +909,30 @@ static int nfs_size_need_update(const struct inode *inode, const struct nfs_fatt return nfs_size_to_loff_t(fattr->size) > i_size_read(inode); } +static unsigned long nfs_attr_generation_counter; + +static unsigned long nfs_read_attr_generation_counter(void) +{ + smp_rmb(); + return nfs_attr_generation_counter; +} + +unsigned long nfs_inc_attr_generation_counter(void) +{ + unsigned long ret; + smp_rmb(); + ret = ++nfs_attr_generation_counter; + smp_wmb(); + return ret; +} + +void nfs_fattr_init(struct nfs_fattr *fattr) +{ + fattr->valid = 0; + fattr->time_start = jiffies; + fattr->gencount = nfs_inc_attr_generation_counter(); +} + /** * nfs_inode_attrs_need_update - check if the inode attributes need updating * @inode - pointer to inode @@ -922,8 +946,7 @@ static int nfs_size_need_update(const struct inode *inode, const struct nfs_fatt * catch the case where ctime either didn't change, or went backwards * (if someone reset the clock on the server) by looking at whether * or not this RPC call was started after the inode was last updated. - * Note also the check for jiffy wraparound if the last_updated timestamp - * is later than 'jiffies'. + * Note also the check for wraparound of 'attr_gencount' * * The function returns 'true' if it thinks the attributes in 'fattr' are * more recent than the ones cached in the inode. @@ -933,10 +956,10 @@ static int nfs_inode_attrs_need_update(const struct inode *inode, const struct n { const struct nfs_inode *nfsi = NFS_I(inode); - return time_after(fattr->time_start, nfsi->last_updated) || + return ((long)fattr->gencount - (long)nfsi->attr_gencount) > 0 || nfs_ctime_need_update(inode, fattr) || nfs_size_need_update(inode, fattr) || - time_after(nfsi->last_updated, jiffies); + ((long)nfsi->attr_gencount - (long)nfs_read_attr_generation_counter() > 0); } static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr) @@ -1107,7 +1130,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) } /* If ctime has changed we should definitely clear access+acl caches */ if (!timespec_equal(&inode->i_ctime, &fattr->ctime)) - invalid |= NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; + invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL; } else if (nfsi->change_attr != fattr->change_attr) { dprintk("NFS: change_attr change on server for file %s/%ld\n", inode->i_sb->s_id, inode->i_ino); @@ -1163,7 +1186,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr) nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE); nfsi->attrtimeo = NFS_MINATTRTIMEO(inode); nfsi->attrtimeo_timestamp = now; - nfsi->last_updated = now; + nfsi->attr_gencount = nfs_inc_attr_generation_counter(); } else { if (!time_in_range(now, nfsi->attrtimeo_timestamp, nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) { if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode)) -- cgit v1.2.1 From 011935a0a710c20bb7ae63523b78856848db1926 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 14 Oct 2008 19:24:50 -0400 Subject: NFS: Fix a resolution problem with nfs_inode->cache_change_attribute The cache_change_attribute is used to decide whether or not a directory has changed, in which case we may need to look it up again. Again, the use of 'jiffies' leads to an issue of resolution. Once again, the fix is to change nfs_inode->cache_change_attribute, and just make it a simple counter. Signed-off-by: Trond Myklebust --- fs/nfs/inode.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/nfs/inode.c') diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 116a3bd2bc9b..b9195c02a863 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -306,7 +306,6 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) nfsi->read_cache_jiffies = fattr->time_start; nfsi->attr_gencount = fattr->gencount; - nfsi->cache_change_attribute = now; inode->i_atime = fattr->atime; inode->i_mtime = fattr->mtime; inode->i_ctime = fattr->ctime; -- cgit v1.2.1