Unless the user is using file locking, we must assume close-to-open
cache consistency when the file is open for writing. Adjust the
caching algorithm so that it does not clear the cache on out-of-order
writes and/or attribute revalidations.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/file.c | 13 ++----------
fs/nfs/inode.c | 62 +++++++++++++++++++++++++++++++++++++++++-----------------
2 files changed, 46 insertions(+), 29 deletions(-)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 717a8d6af52d..2d39d9f9da7d 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -780,11 +780,6 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
}
static int
-is_time_granular(struct timespec *ts) {
- return ((ts->tv_sec == 0) && (ts->tv_nsec <= 1000));
-}
-
-static int
do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
{
struct inode *inode = filp->f_mapping->host;
@@ -817,12 +812,8 @@ do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
* This makes locking act as a cache coherency point.
*/
nfs_sync_mapping(filp->f_mapping);
- if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) {
- if (is_time_granular(&NFS_SERVER(inode)->time_delta))
- __nfs_revalidate_inode(NFS_SERVER(inode), inode);
- else
- nfs_zap_caches(inode);
- }
+ if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+ nfs_zap_mapping(inode, filp->f_mapping);
out:
return status;
}
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 60051e62d3f1..4e65a5a8a01b 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -878,7 +878,10 @@ void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&inode->i_lock);
- list_add(&ctx->list, &nfsi->open_files);
+ if (ctx->mode & FMODE_WRITE)
+ list_add(&ctx->list, &nfsi->open_files);
+ else
+ list_add_tail(&ctx->list, &nfsi->open_files);
spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
@@ -1215,6 +1218,25 @@ int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *
return __nfs_revalidate_mapping(inode, mapping, true);
}
+static bool nfs_file_has_writers(struct nfs_inode *nfsi)
+{
+ struct inode *inode = &nfsi->vfs_inode;
+
+ assert_spin_locked(&inode->i_lock);
+
+ if (!S_ISREG(inode->i_mode))
+ return false;
+ if (list_empty(&nfsi->open_files))
+ return false;
+ /* Note: This relies on nfsi->open_files being ordered with writers
+ * being placed at the head of the list.
+ * See nfs_inode_attach_open_context()
+ */
+ return (list_first_entry(&nfsi->open_files,
+ struct nfs_open_context,
+ list)->mode & FMODE_WRITE) == FMODE_WRITE;
+}
+
static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
{
struct nfs_inode *nfsi = NFS_I(inode);
@@ -1279,22 +1301,24 @@ static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fat
if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
return -EIO;
- if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
- inode->i_version != fattr->change_attr)
- invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
+ if (!nfs_file_has_writers(nfsi)) {
+ /* Verify a few of the more important attributes */
+ if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && inode->i_version != fattr->change_attr)
+ invalid |= NFS_INO_INVALID_ATTR | NFS_INO_REVAL_PAGECACHE;
- /* Verify a few of the more important attributes */
- if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
- invalid |= NFS_INO_INVALID_ATTR;
+ if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec_equal(&inode->i_mtime, &fattr->mtime))
+ invalid |= NFS_INO_INVALID_ATTR;
- if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
- cur_size = i_size_read(inode);
- new_isize = nfs_size_to_loff_t(fattr->size);
- if (cur_size != new_isize)
- invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
+ if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec_equal(&inode->i_ctime, &fattr->ctime))
+ invalid |= NFS_INO_INVALID_ATTR;
+
+ if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
+ cur_size = i_size_read(inode);
+ new_isize = nfs_size_to_loff_t(fattr->size);
+ if (cur_size != new_isize)
+ invalid |= NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
+ }
}
- if (nfsi->nrequests != 0)
- invalid &= ~NFS_INO_REVAL_PAGECACHE;
/* Have any file permissions changed? */
if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
@@ -1526,7 +1550,7 @@ EXPORT_SYMBOL_GPL(nfs_refresh_inode);
static int nfs_post_op_update_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
{
- unsigned long invalid = NFS_INO_INVALID_ATTR|NFS_INO_REVAL_PAGECACHE;
+ unsigned long invalid = NFS_INO_INVALID_ATTR;
/*
* Don't revalidate the pagecache if we hold a delegation, but do
@@ -1675,6 +1699,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
unsigned long invalid = 0;
unsigned long now = jiffies;
unsigned long save_cache_validity;
+ bool have_writers = nfs_file_has_writers(nfsi);
bool cache_revalidated = true;
dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
@@ -1730,7 +1755,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
dprintk("NFS: change_attr change on server for file %s/%ld\n",
inode->i_sb->s_id, inode->i_ino);
/* Could it be a race with writeback? */
- if (nfsi->nrequests == 0) {
+ if (!have_writers) {
invalid |= NFS_INO_INVALID_ATTR
| NFS_INO_INVALID_DATA
| NFS_INO_INVALID_ACCESS
@@ -1770,9 +1795,10 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
if (new_isize != cur_isize) {
/* Do we perhaps have any outstanding writes, or has
* the file grown beyond our last write? */
- if ((nfsi->nrequests == 0) || new_isize > cur_isize) {
+ if (nfsi->nrequests == 0 || new_isize > cur_isize) {
i_size_write(inode, new_isize);
- invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
+ if (!have_writers)
+ invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
}
dprintk("NFS: isize change on server for file %s/%ld "
"(%Ld to %Ld)\n",
--
2.7.4
--
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