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fuse: Trust kernel i_mtime only
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Let the kernel maintain i_mtime locally:
 - clear S_NOCMTIME
 - implement i_op->update_time()
 - flush mtime on fsync and last close
 - update i_mtime explicitly on truncate and fallocate

Fuse inode flag FUSE_I_MTIME_DIRTY serves as indication that local i_mtime
should be flushed to the server eventually.

Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
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Maxim Patlasov authored and Miklos Szeredi committed Apr 2, 2014
1 parent 8373200 commit b0aa760
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Showing 4 changed files with 132 additions and 25 deletions.
108 changes: 91 additions & 17 deletions fs/fuse/dir.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -842,8 +842,11 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
struct fuse_conn *fc = get_fuse_conn(inode);

/* see the comment in fuse_change_attributes() */
if (fc->writeback_cache && S_ISREG(inode->i_mode))
if (fc->writeback_cache && S_ISREG(inode->i_mode)) {
attr->size = i_size_read(inode);
attr->mtime = inode->i_mtime.tv_sec;
attr->mtimensec = inode->i_mtime.tv_nsec;
}

stat->dev = inode->i_sb->s_dev;
stat->ino = attr->ino;
Expand Down Expand Up @@ -1482,12 +1485,16 @@ static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
}

static bool update_mtime(unsigned ivalid)
static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
{
/* Always update if mtime is explicitly set */
if (ivalid & ATTR_MTIME_SET)
return true;

/* Or if kernel i_mtime is the official one */
if (trust_local_mtime)
return true;

/* If it's an open(O_TRUNC) or an ftruncate(), don't update */
if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
return false;
Expand All @@ -1496,7 +1503,8 @@ static bool update_mtime(unsigned ivalid)
return true;
}

static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg,
bool trust_local_mtime)
{
unsigned ivalid = iattr->ia_valid;

Expand All @@ -1515,11 +1523,11 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
if (!(ivalid & ATTR_ATIME_SET))
arg->valid |= FATTR_ATIME_NOW;
}
if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) {
if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_mtime)) {
arg->valid |= FATTR_MTIME;
arg->mtime = iattr->ia_mtime.tv_sec;
arg->mtimensec = iattr->ia_mtime.tv_nsec;
if (!(ivalid & ATTR_MTIME_SET))
if (!(ivalid & ATTR_MTIME_SET) && !trust_local_mtime)
arg->valid |= FATTR_MTIME_NOW;
}
}
Expand Down Expand Up @@ -1568,6 +1576,63 @@ void fuse_release_nowrite(struct inode *inode)
spin_unlock(&fc->lock);
}

static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_req *req,
struct inode *inode,
struct fuse_setattr_in *inarg_p,
struct fuse_attr_out *outarg_p)
{
req->in.h.opcode = FUSE_SETATTR;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
req->in.args[0].size = sizeof(*inarg_p);
req->in.args[0].value = inarg_p;
req->out.numargs = 1;
if (fc->minor < 9)
req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
else
req->out.args[0].size = sizeof(*outarg_p);
req->out.args[0].value = outarg_p;
}

/*
* Flush inode->i_mtime to the server
*/
int fuse_flush_mtime(struct file *file, bool nofail)
{
struct inode *inode = file->f_mapping->host;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req = NULL;
struct fuse_setattr_in inarg;
struct fuse_attr_out outarg;
int err;

if (nofail) {
req = fuse_get_req_nofail_nopages(fc, file);
} else {
req = fuse_get_req_nopages(fc);
if (IS_ERR(req))
return PTR_ERR(req);
}

memset(&inarg, 0, sizeof(inarg));
memset(&outarg, 0, sizeof(outarg));

inarg.valid |= FATTR_MTIME;
inarg.mtime = inode->i_mtime.tv_sec;
inarg.mtimensec = inode->i_mtime.tv_nsec;

fuse_setattr_fill(fc, req, inode, &inarg, &outarg);
fuse_request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);

if (!err)
clear_bit(FUSE_I_MTIME_DIRTY, &fi->state);

return err;
}

/*
* Set attributes, and at the same time refresh them.
*
Expand All @@ -1588,6 +1653,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
bool is_wb = fc->writeback_cache;
loff_t oldsize;
int err;
bool trust_local_mtime = is_wb && S_ISREG(inode->i_mode);

if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
attr->ia_valid |= ATTR_FORCE;
Expand Down Expand Up @@ -1616,7 +1682,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,

memset(&inarg, 0, sizeof(inarg));
memset(&outarg, 0, sizeof(outarg));
iattr_to_fattr(attr, &inarg);
iattr_to_fattr(attr, &inarg, trust_local_mtime);
if (file) {
struct fuse_file *ff = file->private_data;
inarg.valid |= FATTR_FH;
Expand All @@ -1627,17 +1693,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
inarg.valid |= FATTR_LOCKOWNER;
inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
}
req->in.h.opcode = FUSE_SETATTR;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->out.numargs = 1;
if (fc->minor < 9)
req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
else
req->out.args[0].size = sizeof(outarg);
req->out.args[0].value = &outarg;
fuse_setattr_fill(fc, req, inode, &inarg, &outarg);
fuse_request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
Expand All @@ -1654,6 +1710,12 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
}

spin_lock(&fc->lock);
/* the kernel maintains i_mtime locally */
if (trust_local_mtime && (attr->ia_valid & ATTR_MTIME)) {
inode->i_mtime = attr->ia_mtime;
clear_bit(FUSE_I_MTIME_DIRTY, &fi->state);
}

fuse_change_attributes_common(inode, &outarg.attr,
attr_timeout(&outarg));
oldsize = inode->i_size;
Expand Down Expand Up @@ -1884,6 +1946,17 @@ static int fuse_removexattr(struct dentry *entry, const char *name)
return err;
}

static int fuse_update_time(struct inode *inode, struct timespec *now,
int flags)
{
if (flags & S_MTIME) {
inode->i_mtime = *now;
set_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state);
BUG_ON(!S_ISREG(inode->i_mode));
}
return 0;
}

static const struct inode_operations fuse_dir_inode_operations = {
.lookup = fuse_lookup,
.mkdir = fuse_mkdir,
Expand Down Expand Up @@ -1923,6 +1996,7 @@ static const struct inode_operations fuse_common_inode_operations = {
.getxattr = fuse_getxattr,
.listxattr = fuse_listxattr,
.removexattr = fuse_removexattr,
.update_time = fuse_update_time,
};

static const struct inode_operations fuse_symlink_inode_operations = {
Expand Down
30 changes: 26 additions & 4 deletions fs/fuse/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -308,6 +308,9 @@ static int fuse_open(struct inode *inode, struct file *file)

static int fuse_release(struct inode *inode, struct file *file)
{
if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state))
fuse_flush_mtime(file, true);

fuse_release_common(file, FUSE_RELEASE);

/* return value is ignored by VFS */
Expand Down Expand Up @@ -475,6 +478,12 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,

fuse_sync_writes(inode);

if (test_bit(FUSE_I_MTIME_DIRTY, &get_fuse_inode(inode)->state)) {
int err = fuse_flush_mtime(file, false);
if (err)
goto out;
}

req = fuse_get_req_nopages(fc);
if (IS_ERR(req)) {
err = PTR_ERR(req);
Expand Down Expand Up @@ -960,16 +969,21 @@ static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io,
return req->misc.write.out.size;
}

void fuse_write_update_size(struct inode *inode, loff_t pos)
bool fuse_write_update_size(struct inode *inode, loff_t pos)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
bool ret = false;

spin_lock(&fc->lock);
fi->attr_version = ++fc->attr_version;
if (pos > inode->i_size)
if (pos > inode->i_size) {
i_size_write(inode, pos);
ret = true;
}
spin_unlock(&fc->lock);

return ret;
}

static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file,
Expand Down Expand Up @@ -2877,8 +2891,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
goto out;

/* we could have extended the file */
if (!(mode & FALLOC_FL_KEEP_SIZE))
fuse_write_update_size(inode, offset + length);
if (!(mode & FALLOC_FL_KEEP_SIZE)) {
bool changed = fuse_write_update_size(inode, offset + length);

if (changed && fc->writeback_cache) {
struct fuse_inode *fi = get_fuse_inode(inode);

inode->i_mtime = current_fs_time(inode->i_sb);
set_bit(FUSE_I_MTIME_DIRTY, &fi->state);
}
}

if (mode & FALLOC_FL_PUNCH_HOLE)
truncate_pagecache_range(inode, offset, offset + length - 1);
Expand Down
6 changes: 5 additions & 1 deletion fs/fuse/fuse_i.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -119,6 +119,8 @@ enum {
FUSE_I_INIT_RDPLUS,
/** An operation changing file size is in progress */
FUSE_I_SIZE_UNSTABLE,
/** i_mtime has been updated locally; a flush to userspace needed */
FUSE_I_MTIME_DIRTY,
};

struct fuse_conn;
Expand Down Expand Up @@ -876,7 +878,9 @@ long fuse_ioctl_common(struct file *file, unsigned int cmd,
unsigned fuse_file_poll(struct file *file, poll_table *wait);
int fuse_dev_release(struct inode *inode, struct file *file);

void fuse_write_update_size(struct inode *inode, loff_t pos);
bool fuse_write_update_size(struct inode *inode, loff_t pos);

int fuse_flush_mtime(struct file *file, bool nofail);

int fuse_do_setattr(struct inode *inode, struct iattr *attr,
struct file *file);
Expand Down
13 changes: 10 additions & 3 deletions fs/fuse/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -170,8 +170,11 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
inode->i_blocks = attr->blocks;
inode->i_atime.tv_sec = attr->atime;
inode->i_atime.tv_nsec = attr->atimensec;
inode->i_mtime.tv_sec = attr->mtime;
inode->i_mtime.tv_nsec = attr->mtimensec;
/* mtime from server may be stale due to local buffered write */
if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
inode->i_mtime.tv_sec = attr->mtime;
inode->i_mtime.tv_nsec = attr->mtimensec;
}
inode->i_ctime.tv_sec = attr->ctime;
inode->i_ctime.tv_nsec = attr->ctimensec;

Expand Down Expand Up @@ -250,6 +253,8 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
inode->i_mode = attr->mode & S_IFMT;
inode->i_size = attr->size;
inode->i_mtime.tv_sec = attr->mtime;
inode->i_mtime.tv_nsec = attr->mtimensec;
if (S_ISREG(inode->i_mode)) {
fuse_init_common(inode);
fuse_init_file_inode(inode);
Expand Down Expand Up @@ -296,7 +301,9 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
return NULL;

if ((inode->i_state & I_NEW)) {
inode->i_flags |= S_NOATIME|S_NOCMTIME;
inode->i_flags |= S_NOATIME;
if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
inode->i_flags |= S_NOCMTIME;
inode->i_generation = generation;
inode->i_data.backing_dev_info = &fc->bdi;
fuse_init_inode(inode, attr);
Expand Down

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