diff options
Diffstat (limited to 'fs/cifs/file.c')
| -rw-r--r-- | fs/cifs/file.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 5920820bfbd0..0b1528edebcf 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -4808,6 +4808,60 @@ cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter) return -EINVAL; } +static int cifs_swap_activate(struct swap_info_struct *sis, + struct file *swap_file, sector_t *span) +{ + struct cifsFileInfo *cfile = swap_file->private_data; + struct inode *inode = swap_file->f_mapping->host; + unsigned long blocks; + long long isize; + + cifs_dbg(FYI, "swap activate\n"); + + spin_lock(&inode->i_lock); + blocks = inode->i_blocks; + isize = inode->i_size; + spin_unlock(&inode->i_lock); + if (blocks*512 < isize) { + pr_warn("swap activate: swapfile has holes\n"); + return -EINVAL; + } + *span = sis->pages; + + printk_once(KERN_WARNING "Swap support over SMB3 is experimental\n"); + + /* + * TODO: consider adding ACL (or documenting how) to prevent other + * users (on this or other systems) from reading it + */ + + + /* TODO: add sk_set_memalloc(inet) or similar */ + + if (cfile) + cfile->swapfile = true; + /* + * TODO: Since file already open, we can't open with DENY_ALL here + * but we could add call to grab a byte range lock to prevent others + * from reading or writing the file + */ + + return 0; +} + +static void cifs_swap_deactivate(struct file *file) +{ + struct cifsFileInfo *cfile = file->private_data; + + cifs_dbg(FYI, "swap deactivate\n"); + + /* TODO: undo sk_set_memalloc(inet) will eventually be needed */ + + if (cfile) + cfile->swapfile = false; + + /* do we need to unpin (or unlock) the file */ +} const struct address_space_operations cifs_addr_ops = { .readpage = cifs_readpage, @@ -4821,6 +4875,13 @@ const struct address_space_operations cifs_addr_ops = { .direct_IO = cifs_direct_io, .invalidatepage = cifs_invalidate_page, .launder_page = cifs_launder_page, + /* + * TODO: investigate and if useful we could add an cifs_migratePage + * helper (under an CONFIG_MIGRATION) in the future, and also + * investigate and add an is_dirty_writeback helper if needed + */ + .swap_activate = cifs_swap_activate, + .swap_deactivate = cifs_swap_deactivate, }; /* |