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author | Dominique Martinet <dominique.martinet@cea.fr> | 2014-01-10 13:44:09 +0100 |
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committer | Eric Van Hensbergen <ericvh@gmail.com> | 2014-01-10 09:20:51 -0600 |
commit | fb89b45cdfdc8bdab93986f1bc1474e313295c31 (patch) | |
tree | c19ec0f84315c6dc77ca2447f58e2508b76ce88a /fs/9p/vfs_file.c | |
parent | f94741fd2832e7abc30fbf6dc13ed627c1fcc01a (diff) | |
download | linux-stable-fb89b45cdfdc8bdab93986f1bc1474e313295c31.tar.gz linux-stable-fb89b45cdfdc8bdab93986f1bc1474e313295c31.tar.bz2 linux-stable-fb89b45cdfdc8bdab93986f1bc1474e313295c31.zip |
9P: introduction of a new cache=mmap model.
- Add cache=mmap option
- Make mmap read-write while keeping it as synchronous as possible
- Build writeback fid on mmap creation if it is writable
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p/vfs_file.c')
-rw-r--r-- | fs/9p/vfs_file.c | 140 |
1 files changed, 136 insertions, 4 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 27782bb7f4f9..a16b0ff497ca 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -45,6 +45,7 @@ #include "cache.h" static const struct vm_operations_struct v9fs_file_vm_ops; +static const struct vm_operations_struct v9fs_mmap_file_vm_ops; /** * v9fs_file_open - open a file (or directory) @@ -87,7 +88,8 @@ int v9fs_file_open(struct inode *inode, struct file *file) file->private_data = fid; mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid && + if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) && + !v9inode->writeback_fid && ((file->f_flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid @@ -105,7 +107,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) v9inode->writeback_fid = (void *) fid; } mutex_unlock(&v9inode->v_mutex); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) v9fs_cache_inode_set_cookie(inode, file); return 0; out_error: @@ -579,11 +581,12 @@ int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end, } static int -v9fs_file_mmap(struct file *file, struct vm_area_struct *vma) +v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma) { int retval; - retval = generic_file_mmap(file, vma); + + retval = generic_file_mmap(filp, vma); if (!retval) vma->vm_ops = &v9fs_file_vm_ops; @@ -591,6 +594,43 @@ v9fs_file_mmap(struct file *file, struct vm_area_struct *vma) } static int +v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma) +{ + int retval; + struct inode *inode; + struct v9fs_inode *v9inode; + struct p9_fid *fid; + + inode = file_inode(filp); + v9inode = V9FS_I(inode); + mutex_lock(&v9inode->v_mutex); + if (!v9inode->writeback_fid && + (vma->vm_flags & VM_WRITE)) { + /* + * clone a fid and add it to writeback_fid + * we do it during mmap instead of + * page dirty time via write_begin/page_mkwrite + * because we want write after unlink usecase + * to work. + */ + fid = v9fs_writeback_fid(filp->f_path.dentry); + if (IS_ERR(fid)) { + retval = PTR_ERR(fid); + mutex_unlock(&v9inode->v_mutex); + return retval; + } + v9inode->writeback_fid = (void *) fid; + } + mutex_unlock(&v9inode->v_mutex); + + retval = generic_file_mmap(filp, vma); + if (!retval) + vma->vm_ops = &v9fs_mmap_file_vm_ops; + + return retval; +} + +static int v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct v9fs_inode *v9inode; @@ -658,6 +698,22 @@ v9fs_cached_file_read(struct file *filp, char __user *data, size_t count, return do_sync_read(filp, data, count, offset); } +/** + * v9fs_mmap_file_read - read from a file + * @filp: file pointer to read + * @udata: user data buffer to read data into + * @count: size of buffer + * @offset: offset at which to read data + * + */ +static ssize_t +v9fs_mmap_file_read(struct file *filp, char __user *data, size_t count, + loff_t *offset) +{ + /* TODO: Check if there are dirty pages */ + return v9fs_file_read(filp, data, count, offset); +} + static ssize_t v9fs_direct_write(struct file *filp, const char __user * data, size_t count, loff_t *offsetp) @@ -728,12 +784,65 @@ v9fs_cached_file_write(struct file *filp, const char __user * data, return do_sync_write(filp, data, count, offset); } + +/** + * v9fs_mmap_file_write - write to a file + * @filp: 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_mmap_file_write(struct file *filp, const char __user *data, + size_t count, loff_t *offset) +{ + /* + * TODO: invalidate mmaps on filp's inode between + * offset and offset+count + */ + return v9fs_file_write(filp, data, count, offset); +} + +static void v9fs_mmap_vm_close(struct vm_area_struct *vma) +{ + struct inode *inode; + + struct writeback_control wbc = { + .nr_to_write = LONG_MAX, + .sync_mode = WB_SYNC_ALL, + .range_start = vma->vm_pgoff * PAGE_SIZE, + /* absolute end, byte at end included */ + .range_end = vma->vm_pgoff * PAGE_SIZE + + (vma->vm_end - vma->vm_start - 1), + }; + + + p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma); + + inode = file_inode(vma->vm_file); + + if (!mapping_cap_writeback_dirty(inode->i_mapping)) + wbc.nr_to_write = 0; + + might_sleep(); + sync_inode(inode, &wbc); +} + + static const struct vm_operations_struct v9fs_file_vm_ops = { .fault = filemap_fault, .page_mkwrite = v9fs_vm_page_mkwrite, .remap_pages = generic_file_remap_pages, }; +static const struct vm_operations_struct v9fs_mmap_file_vm_ops = { + .close = v9fs_mmap_vm_close, + .fault = filemap_fault, + .page_mkwrite = v9fs_vm_page_mkwrite, + .remap_pages = generic_file_remap_pages, +}; + const struct file_operations v9fs_cached_file_operations = { .llseek = generic_file_llseek, @@ -784,3 +893,26 @@ const struct file_operations v9fs_file_operations_dotl = { .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync_dotl, }; + +const struct file_operations v9fs_mmap_file_operations = { + .llseek = generic_file_llseek, + .read = v9fs_mmap_file_read, + .write = v9fs_mmap_file_write, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock, + .mmap = v9fs_mmap_file_mmap, + .fsync = v9fs_file_fsync, +}; + +const struct file_operations v9fs_mmap_file_operations_dotl = { + .llseek = generic_file_llseek, + .read = v9fs_mmap_file_read, + .write = v9fs_mmap_file_write, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock_dotl, + .flock = v9fs_file_flock_dotl, + .mmap = v9fs_mmap_file_mmap, + .fsync = v9fs_file_fsync_dotl, +}; 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