Loose cache mode was added primarily to asssist exclusive, read-only
mounts (like venti) -- however, there is also a case for using loose
write cacheing in support of read/write exclusive mounts. This feature
is linked to the loose cache option and is disabled by default.
This code adds the necessary code to support writes through the page
cache. Write caches are not used for synthetic files or for files opened
in APPEND mode.
Signed-of-by: Eric Van Hensbergen <[email protected]>
---
Documentation/filesystems/9p.txt | 2
fs/9p/9p.h | 2
fs/9p/conv.c | 19 ++++
fs/9p/conv.h | 2
fs/9p/fcall.c | 6 +
fs/9p/fid.c | 17 ++--
fs/9p/fid.h | 2
fs/9p/v9fs_vfs.h | 2
fs/9p/vfs_addr.c | 180 ++++++++++++++++++++++++++++++++++++--
fs/9p/vfs_dir.c | 2
fs/9p/vfs_file.c | 58 ++++++++++--
fs/9p/vfs_inode.c | 13 ++-
fs/9p/vfs_super.c | 3 -
13 files changed, 264 insertions(+), 44 deletions(-)
diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index bbd8b28..36ed211 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -42,7 +42,7 @@ OPTIONS
cache=mode specifies a cacheing policy. By default, no caches are used.
loose = no attempts are made at consistency,
- intended for exclusive, read-only mounts
+ intended for exclusive mounts
debug=n specifies debug level. The debug level is a bitmask.
0x01 = display verbose error messages
diff --git a/fs/9p/9p.h b/fs/9p/9p.h
index 94e2f92..6f8edf0 100644
--- a/fs/9p/9p.h
+++ b/fs/9p/9p.h
@@ -370,6 +370,6 @@ int v9fs_t_read(struct v9fs_session_info
u64 offset, u32 count, struct v9fs_fcall **rcall);
int v9fs_t_write(struct v9fs_session_info *v9ses, u32 fid, u64 offset,
- u32 count, const char __user * data,
+ u32 count, const char __user * data, char * kdata,
struct v9fs_fcall **rcall);
int v9fs_printfcall(char *, int, struct v9fs_fcall *, int);
diff --git a/fs/9p/conv.c b/fs/9p/conv.c
index a3ed571..89c3d3c 100644
--- a/fs/9p/conv.c
+++ b/fs/9p/conv.c
@@ -458,6 +458,15 @@ v9fs_put_user_data(struct cbuf *bufp, co
return copy_from_user(*pdata, data, count);
}
+static int
+v9fs_put_kernel_data(struct cbuf *bufp, char * kdata, int count,
+ unsigned char **pdata)
+{
+ *pdata = buf_alloc(bufp, count);
+ memcpy(*pdata, kdata, count);
+ return 0;
+}
+
static void
v9fs_put_wstat(struct cbuf *bufp, struct v9fs_wstat *wstat,
struct v9fs_stat *stat, int statsz, int extended)
@@ -723,7 +732,7 @@ struct v9fs_fcall *v9fs_create_tread(u32
}
struct v9fs_fcall *v9fs_create_twrite(u32 fid, u64 offset, u32 count,
- const char __user * data)
+ const char __user * data, char * kdata)
{
int size, err;
struct v9fs_fcall *fc;
@@ -738,7 +747,13 @@ struct v9fs_fcall *v9fs_create_twrite(u3
v9fs_put_int32(bufp, fid, &fc->params.twrite.fid);
v9fs_put_int64(bufp, offset, &fc->params.twrite.offset);
v9fs_put_int32(bufp, count, &fc->params.twrite.count);
- err = v9fs_put_user_data(bufp, data, count, &fc->params.twrite.data);
+ if(data) {
+ err = v9fs_put_user_data(bufp, data, count,
+ &fc->params.twrite.data);
+ } else {
+ err = v9fs_put_kernel_data(bufp, kdata, count,
+ &fc->params.twrite.data);
+ }
if (err) {
kfree(fc);
fc = ERR_PTR(err);
diff --git a/fs/9p/conv.h b/fs/9p/conv.h
index dd5b6b1..8091672 100644
--- a/fs/9p/conv.h
+++ b/fs/9p/conv.h
@@ -42,7 +42,7 @@ struct v9fs_fcall *v9fs_create_tcreate(u
char *extension, int extended);
struct v9fs_fcall *v9fs_create_tread(u32 fid, u64 offset, u32 count);
struct v9fs_fcall *v9fs_create_twrite(u32 fid, u64 offset, u32 count,
- const char __user *data);
+ const char __user *data, char *kdata);
struct v9fs_fcall *v9fs_create_tclunk(u32 fid);
struct v9fs_fcall *v9fs_create_tremove(u32 fid);
struct v9fs_fcall *v9fs_create_tstat(u32 fid);
diff --git a/fs/9p/fcall.c b/fs/9p/fcall.c
index dc336a6..671301a 100644
--- a/fs/9p/fcall.c
+++ b/fs/9p/fcall.c
@@ -393,13 +393,15 @@ v9fs_t_read(struct v9fs_session_info *v9
* @fid: fid to write to
* @offset: offset to start write at
* @count: how many bytes to write
+ * @data: userspace data
+ * @kdata: kernelspace data
* @fcall: pointer to response fcall
*
*/
int
v9fs_t_write(struct v9fs_session_info *v9ses, u32 fid, u64 offset, u32 count,
- const char __user *data, struct v9fs_fcall **rcp)
+ const char __user *data, char *kdata, struct v9fs_fcall **rcp)
{
int ret;
struct v9fs_fcall *tc, *rc;
@@ -407,7 +409,7 @@ v9fs_t_write(struct v9fs_session_info *v
dprintk(DEBUG_9P, "fid %d offset 0x%llux count 0x%x\n", fid,
(long long unsigned) offset, count);
- tc = v9fs_create_twrite(fid, offset, count, data);
+ tc = v9fs_create_twrite(fid, offset, count, data, kdata);
if (!IS_ERR(tc)) {
ret = v9fs_mux_rpc(v9ses->mux, tc, &rc);
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 9041971..f3c5cb8 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -40,19 +40,18 @@ #include "fid.h"
*
*/
-int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry)
+int v9fs_fid_insert(struct v9fs_fid *fid, void **priv)
{
- struct list_head *fid_list = (struct list_head *)dentry->d_fsdata;
- dprintk(DEBUG_9P, "fid %d (%p) dentry %s (%p)\n", fid->fid, fid,
- dentry->d_iname, dentry);
- if (dentry->d_fsdata == NULL) {
- dentry->d_fsdata =
+ struct list_head *fid_list= (struct list_head *) *priv;
+
+ if (fid_list == NULL) {
+ *priv =
kmalloc(sizeof(struct list_head), GFP_KERNEL);
- if (dentry->d_fsdata == NULL) {
+ if (*priv == NULL) {
dprintk(DEBUG_ERROR, "Out of memory\n");
return -ENOMEM;
}
- fid_list = (struct list_head *)dentry->d_fsdata;
+ fid_list = (struct list_head *)*priv;
INIT_LIST_HEAD(fid_list); /* Initialize list head */
}
@@ -80,6 +79,7 @@ struct v9fs_fid *v9fs_fid_create(struct
new->fid = fid;
new->v9ses = v9ses;
+ new->filp = NULL;
new->fidopen = 0;
new->fidclunked = 0;
new->iounit = 0;
@@ -192,3 +192,4 @@ void v9fs_fid_clunk(struct v9fs_session_
v9fs_t_clunk(v9ses, fid->fid);
v9fs_fid_destroy(fid);
}
+
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index 48fc170..dd19181 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -56,7 +56,7 @@ struct v9fs_fid *v9fs_fid_lookup(struct
struct v9fs_fid *v9fs_fid_get_created(struct dentry *);
void v9fs_fid_destroy(struct v9fs_fid *fid);
struct v9fs_fid *v9fs_fid_create(struct v9fs_session_info *, int fid);
-int v9fs_fid_insert(struct v9fs_fid *fid, struct dentry *dentry);
+int v9fs_fid_insert(struct v9fs_fid *fid, void **priv);
struct v9fs_fid *v9fs_fid_clone(struct dentry *dentry);
void v9fs_fid_clunk(struct v9fs_session_info *v9ses, struct v9fs_fid *fid);
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 8ada4c5..27f11eb 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -53,3 +53,5 @@ int v9fs_file_open(struct inode *inode,
void v9fs_inode2stat(struct inode *inode, struct v9fs_stat *stat);
void v9fs_dentry_release(struct dentry *);
int v9fs_uflags2omode(int uflags);
+ssize_t v9fs_write(struct file *filp, const char __user * data, char * kdata, size_t count, loff_t * offset);
+
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index bed48fa..6cdd6b0 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -6,6 +6,9 @@
* Copyright (C) 2005 by Eric Van Hensbergen <[email protected]>
* Copyright (C) 2002 by Ron Minnich <[email protected]>
*
+ * Some operations based on code from fs/cifs/file.c
+ * Copyright (C) International Business Machines Corp., 2002,2003
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
@@ -41,14 +44,14 @@ #include "v9fs_vfs.h"
#include "fid.h"
/**
- * v9fs_vfs_readpage - read an entire page in from 9P
+ * v9fs_vfs_readpage_worker - read an entire page in from 9P
*
* @file: file being read
* @page: structure to page
*
*/
-static int v9fs_vfs_readpage(struct file *filp, struct page *page)
+static int v9fs_vfs_readpage_worker(struct file *filp, struct page *page)
{
char *buffer = NULL;
int retval = -EIO;
@@ -63,8 +66,7 @@ static int v9fs_vfs_readpage(struct file
int total = 0;
int result = 0;
- dprintk(DEBUG_VFS, "\n");
-
+ page_cache_get(page);
buffer = kmap(page);
do {
if (count < rsize)
@@ -73,13 +75,13 @@ static int v9fs_vfs_readpage(struct file
result = v9fs_t_read(v9ses, fid, offset, rsize, &fcall);
if (result < 0) {
- printk(KERN_ERR "v9fs_t_read returned %d\n",
- result);
+ printk(KERN_ERR "v9fs_t_read returned %d\n", result);
kfree(fcall);
- goto UnmapAndUnlock;
- } else
+ goto io_error;
+ } else {
offset += result;
+ }
memcpy(buffer, fcall->params.rread.data, result);
@@ -98,12 +100,170 @@ static int v9fs_vfs_readpage(struct file
SetPageUptodate(page);
retval = 0;
-UnmapAndUnlock:
+ io_error:
+ kunmap(page);
+ page_cache_release(page);
+ return retval;
+}
+
+/**
+ * v9fs_prepare_write - prepare for mmap or page-cache I/O
+ *
+ * @file: file being read
+ * @page: structure to page
+ * @from: starting offset
+ * @to: ending offset
+ *
+ * This is mostly just a
+ *
+ */
+
+int v9fs_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ if (!PageUptodate(page)) {
+ if (to - from != PAGE_CACHE_SIZE) {
+ void *kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr, 0, from);
+ memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ }
+ SetPageUptodate(page);
+ }
+
+ if ((to == PAGE_CACHE_SIZE) && (from == 0))
+ SetPageUptodate(page);
+
+ if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
+ v9fs_vfs_readpage_worker(file, page);
+ }
+
+ return 0;
+}
+
+/**
+ * v9fs_vfs_readpage - read an entire page in from 9P
+ *
+ * @file: file being read
+ * @page: structure to page
+ *
+ */
+
+static int v9fs_vfs_readpage(struct file *filp, struct page *page)
+{
+ int retval;
+
+ dprintk(DEBUG_VFS, "\n");
+
+ retval = v9fs_vfs_readpage_worker(filp, page);
+
+ unlock_page(page);
+ return retval;
+}
+
+/**
+ * v9fs_find_file - find a file pointer based on page
+ * @page: page to lookup file based on
+ *
+ */
+static struct file *v9fs_find_file(struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct v9fs_fid *fid = NULL;
+ struct list_head *p;
+
+ dprintk(DEBUG_VFS, " page: %p\n", page);
+
+ p = (struct list_head *)inode->i_private;
+ if (!p) {
+ dprintk(DEBUG_ERROR, "No list_head\n");
+ return NULL;
+ }
+
+ fid = list_entry(p->next, struct v9fs_fid, list);
+
+ if (fid)
+ return fid->filp;
+
+ dprintk(DEBUG_VFS, " filp not found for page: %p\n", page);
+ return NULL;
+}
+
+/**
+ * v9fs_vfs_writepage - write a mmaped page to server
+ * @page: page to write
+ * @wbc: writeback control
+ *
+ */
+
+static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ char *buffer = NULL;
+ struct address_space *mapping = page->mapping;
+ int retval = -EIO;
+ loff_t offset = 0;
+ loff_t pageoffset = 0;
+ unsigned long end_index;
+ int count = PAGE_CACHE_SIZE;
+ struct file *filp = v9fs_find_file(page);
+ struct inode *inode = mapping->host;
+
+ dprintk(DEBUG_VFS, "page: %p\n", page);
+
+ if ((!inode) || (!filp))
+ goto UnlockPage;
+
+ end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+
+ /* complicated case at end of file */
+ if (page->index >= end_index) {
+ /* things got complicated... */
+ count = inode->i_size & (PAGE_CACHE_SIZE - 1);
+ if (page->index >= end_index + 1 || !count)
+ return 0; /* truncated - don't care */
+ }
+
+ /* get buffer */
+ buffer = kmap(page) + pageoffset;
+ offset = ((loff_t) page->index << PAGE_CACHE_SHIFT) + pageoffset;
+
+ page_cache_get(page);
+
+ retval = v9fs_write(filp, NULL, buffer, count, &offset);
+
+ if (retval < 0) {
+ dprintk(DEBUG_ERROR, "error: %d\n", retval);
+ ClearPageUptodate(page);
+ goto UnmapPage;
+ }
+
+ if (retval < count) {
+ dprintk(DEBUG_ERROR, "Short write\n");
+ }
+
+ if (offset > inode->i_size) {
+ inode->i_size = offset;
+ }
+
+ if (PageError(page))
+ ClearPageError(page);
+ SetPageUptodate(page);
+
+ retval = 0;
+
+ UnmapPage:
kunmap(page);
+ UnlockPage:
unlock_page(page);
+ page_cache_release(page);
+
return retval;
}
const struct address_space_operations v9fs_addr_operations = {
- .readpage = v9fs_vfs_readpage,
+ .prepare_write = v9fs_prepare_write,
+ .commit_write = simple_commit_write,
+ .readpage = v9fs_vfs_readpage,
+ .writepage = v9fs_vfs_writepage,
};
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 3129688..8559f7a 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -197,7 +197,7 @@ int v9fs_dir_release(struct inode *inode
dprintk(DEBUG_ERROR, "clunk failed\n");
kfree(fid->rdir_fcall);
- kfree(fid);
+ v9fs_fid_destroy(fid);
filp->private_data = NULL;
}
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 653dfa5..f26f628 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -79,13 +79,14 @@ int v9fs_file_open(struct inode *inode,
vfid->filp = file;
kfree(fcall);
- if((vfid->qid.version) && (v9ses->cache)) {
- dprintk(DEBUG_VFS, "cached");
+ if((vfid->qid.version) && (v9ses->cache) && !(file->f_flags&O_APPEND)) {
/* enable cached file options */
if(file->f_op == &v9fs_file_operations)
file->f_op = &v9fs_cached_file_operations;
}
+ v9fs_fid_insert(vfid, &inode->i_private);
+
return 0;
Clunk_Fid:
@@ -187,17 +188,18 @@ v9fs_file_read(struct file *filp, char _
}
/**
- * v9fs_file_write - write to a file
+ * v9fs_write - write to a file (generic)
* @filep: file pointer to write
- * @data: data buffer to write data from
+ * @data: user data buffer to write data from
+ * @kdata: kernel data buffer to write data from
* @count: size of buffer
* @offset: offset at which to write data
*
*/
-static ssize_t
-v9fs_file_write(struct file *filp, const char __user * data,
- size_t count, loff_t * offset)
+ssize_t
+v9fs_write(struct file *filp, const char __user * data,
+ char* kdata, size_t count, loff_t * offset)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
@@ -208,8 +210,8 @@ v9fs_file_write(struct file *filp, const
int rsize = 0;
int total = 0;
- dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count,
- (int)*offset);
+ dprintk(DEBUG_VFS, "count %d offset %x\n",
+ (int)count, (int)*offset);
rsize = v9ses->maxdata - V9FS_IOHDRSZ;
if (v9fid->iounit != 0 && rsize > v9fid->iounit)
rsize = v9fid->iounit;
@@ -218,7 +220,8 @@ v9fs_file_write(struct file *filp, const
if (count < rsize)
rsize = count;
- result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall);
+ result = v9fs_t_write(v9ses, fid, *offset, rsize,
+ data, kdata, &fcall);
if (result < 0) {
PRINT_FCALL_ERROR("error while writing", fcall);
kfree(fcall);
@@ -237,19 +240,48 @@ v9fs_file_write(struct file *filp, const
}
count -= result;
- data += result;
+ if(data)
+ data += result;
+ else
+ kdata += result;
total += result;
} while (count);
- invalidate_inode_pages2(inode->i_mapping);
return total;
}
+
+/**
+ * v9fs_file_write - write to a file
+ * @filep: file pointer to write
+ * @data: data buffer to write data from
+ * @count: size of buffer
+ * @offset: offset at which to write data
+ *
+ */
+
+static ssize_t
+v9fs_file_write(struct file *filp, const char __user * data,
+ size_t count, loff_t * offset)
+{
+ struct inode *inode = filp->f_path.dentry->d_inode;
+
+ ssize_t ret;
+
+ dprintk(DEBUG_VFS, "count %d offset %x\n",
+ (int)count, (int)*offset);
+ ret = v9fs_write(filp, data, NULL, count, offset);
+ invalidate_inode_pages2(inode->i_mapping);
+ return ret;
+}
+
const struct file_operations v9fs_cached_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.aio_read = generic_file_aio_read,
- .write = v9fs_file_write,
+ .write = do_sync_write,
+ .aio_write = generic_file_aio_write,
+ .fsync = simple_sync_file,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 124a085..4099b0e 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -208,6 +208,7 @@ struct inode *v9fs_get_inode(struct supe
inode->i_rdev = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_mapping->a_ops = &v9fs_addr_operations;
+ inode->i_private = NULL;
switch (mode & S_IFMT) {
case S_IFIFO:
@@ -340,7 +341,7 @@ v9fs_clone_walk(struct v9fs_session_info
goto clunk_fid;
}
- err = v9fs_fid_insert(ret, dentry);
+ err = v9fs_fid_insert(ret, &dentry->d_fsdata);
if (err < 0) {
v9fs_fid_destroy(ret);
goto clunk_fid;
@@ -520,13 +521,19 @@ v9fs_vfs_create(struct inode *dir, struc
v9fs_fid_destroy(ffid);
return PTR_ERR(filp);
}
-
ffid->rdir_pos = 0;
ffid->rdir_fcall = NULL;
ffid->fidopen = 1;
ffid->iounit = iounit;
ffid->filp = filp;
filp->private_data = ffid;
+ if((vfid->qid.version) && (v9ses->cache) &&
+ !(flags & O_APPEND)) {
+ /* enable cached file options */
+ if(filp->f_op == &v9fs_file_operations)
+ filp->f_op = &v9fs_cached_file_operations;
+ }
+ v9fs_fid_insert(ffid, &inode->i_private);
}
return 0;
@@ -696,7 +703,7 @@ static struct dentry *v9fs_vfs_lookup(st
goto FreeFcall;
}
- result = v9fs_fid_insert(fid, dentry);
+ result = v9fs_fid_insert(fid, &dentry->d_fsdata);
if (result < 0)
goto FreeFcall;
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 0ec42f6..7c4c289 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -56,6 +56,7 @@ static const struct super_operations v9f
static void v9fs_clear_inode(struct inode *inode)
{
filemap_fdatawrite(inode->i_mapping);
+ kfree(inode->i_private);
}
/**
@@ -167,7 +168,7 @@ static int v9fs_get_sb(struct file_syste
goto put_back_sb;
}
- retval = v9fs_fid_insert(root_fid, root);
+ retval = v9fs_fid_insert(root_fid, &root->d_fsdata);
if (retval < 0) {
kfree(fcall);
goto put_back_sb;
--
1.4.1
-
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