file.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*
    2  *  file.c
    3  *
    4  *  Copyright (C) 1995, 1996, 1997 by Paal-Kr. Engstad and Volker Lendecke
    5  *  Copyright (C) 1997 by Volker Lendecke
    6  *
    7  *  Please add a note about your changes to smbfs in the ChangeLog file.
    8  */
    9 
   10 #include <linux/time.h>
   11 #include <linux/kernel.h>
   12 #include <linux/errno.h>
   13 #include <linux/fcntl.h>
   14 #include <linux/stat.h>
   15 #include <linux/mm.h>
   16 #include <linux/pagemap.h>
   17 #include <linux/smp_lock.h>
   18 #include <linux/net.h>
   19 #include <linux/aio.h>
   20 
   21 #include <asm/uaccess.h>
   22 #include <asm/system.h>
   23 
   24 #include <linux/smbno.h>
   25 #include <linux/smb_fs.h>
   26 
   27 #include "smb_debug.h"
   28 #include "proto.h"
   29 
   30 static int
   31 smb_fsync(struct file *file, int datasync)
   32 {
   33         struct dentry *dentry = file->f_path.dentry;
   34         struct smb_sb_info *server = server_from_dentry(dentry);
   35         int result;
   36 
   37         VERBOSE("sync file %s/%s\n", DENTRY_PATH(dentry));
   38 
   39         /*
   40          * The VFS will writepage() all dirty pages for us, but we
   41          * should send a SMBflush to the server, letting it know that
   42          * we want things synchronized with actual storage.
   43          *
   44          * Note: this function requires all pages to have been written already
   45          *       (should be ok with writepage_sync)
   46          */
   47         result = smb_proc_flush(server, SMB_I(dentry->d_inode)->fileid);
   48         return result;
   49 }
   50 
   51 /*
   52  * Read a page synchronously.
   53  */
   54 static int
   55 smb_readpage_sync(struct dentry *dentry, struct page *page)
   56 {
   57         char *buffer = kmap(page);
   58         loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
   59         struct smb_sb_info *server = server_from_dentry(dentry);
   60         unsigned int rsize = smb_get_rsize(server);
   61         int count = PAGE_SIZE;
   62         int result;
   63 
   64         VERBOSE("file %s/%s, count=%d@%Ld, rsize=%d\n",
   65                 DENTRY_PATH(dentry), count, offset, rsize);
   66 
   67         result = smb_open(dentry, SMB_O_RDONLY);
   68         if (result < 0)
   69                 goto io_error;
   70 
   71         do {
   72                 if (count < rsize)
   73                         rsize = count;
   74 
   75                 result = server->ops->read(dentry->d_inode,offset,rsize,buffer);
   76                 if (result < 0)
   77                         goto io_error;
   78 
   79                 count -= result;
   80                 offset += result;
   81                 buffer += result;
   82                 dentry->d_inode->i_atime =
   83                         current_fs_time(dentry->d_inode->i_sb);
   84                 if (result < rsize)
   85                         break;
   86         } while (count);
   87 
   88         memset(buffer, 0, count);
   89         flush_dcache_page(page);
   90         SetPageUptodate(page);
   91         result = 0;
   92 
   93 io_error:
   94         kunmap(page);
   95         unlock_page(page);
   96         return result;
   97 }
   98 
   99 /*
  100  * We are called with the page locked and we unlock it when done.
  101  */
  102 static int
  103 smb_readpage(struct file *file, struct page *page)
  104 {
  105         int             error;
  106         struct dentry  *dentry = file->f_path.dentry;
  107 
  108         page_cache_get(page);
  109         error = smb_readpage_sync(dentry, page);
  110         page_cache_release(page);
  111         return error;
  112 }
  113 
  114 /*
  115  * Write a page synchronously.
  116  * Offset is the data offset within the page.
  117  */
  118 static int
  119 smb_writepage_sync(struct inode *inode, struct page *page,
  120                    unsigned long pageoffset, unsigned int count)
  121 {
  122         loff_t offset;
  123         char *buffer = kmap(page) + pageoffset;
  124         struct smb_sb_info *server = server_from_inode(inode);
  125         unsigned int wsize = smb_get_wsize(server);
  126         int ret = 0;
  127 
  128         offset = ((loff_t)page->index << PAGE_CACHE_SHIFT) + pageoffset;
  129         VERBOSE("file ino=%ld, fileid=%d, count=%d@%Ld, wsize=%d\n",
  130                 inode->i_ino, SMB_I(inode)->fileid, count, offset, wsize);
  131 
  132         do {
  133                 int write_ret;
  134 
  135                 if (count < wsize)
  136                         wsize = count;
  137 
  138                 write_ret = server->ops->write(inode, offset, wsize, buffer);
  139                 if (write_ret < 0) {
  140                         PARANOIA("failed write, wsize=%d, write_ret=%d\n",
  141                                  wsize, write_ret);
  142                         ret = write_ret;
  143                         break;
  144                 }
  145                 /* N.B. what if result < wsize?? */
  146 #ifdef SMBFS_PARANOIA
  147                 if (write_ret < wsize)
  148                         PARANOIA("short write, wsize=%d, write_ret=%d\n",
  149                                  wsize, write_ret);
  150 #endif
  151                 buffer += wsize;
  152                 offset += wsize;
  153                 count -= wsize;
  154                 /*
  155                  * Update the inode now rather than waiting for a refresh.
  156                  */
  157                 inode->i_mtime = inode->i_atime = current_fs_time(inode->i_sb);
  158                 SMB_I(inode)->flags |= SMB_F_LOCALWRITE;
  159                 if (offset > inode->i_size)
  160                         inode->i_size = offset;
  161         } while (count);
  162 
  163         kunmap(page);
  164         return ret;
  165 }
  166 
  167 /*
  168  * Write a page to the server. This will be used for NFS swapping only
  169  * (for now), and we currently do this synchronously only.
  170  *
  171  * We are called with the page locked and we unlock it when done.
  172  */
  173 static int
  174 smb_writepage(struct page *page, struct writeback_control *wbc)
  175 {
  176         struct address_space *mapping = page->mapping;
  177         struct inode *inode;
  178         unsigned long end_index;
  179         unsigned offset = PAGE_CACHE_SIZE;
  180         int err;
  181 
  182         BUG_ON(!mapping);
  183         inode = mapping->host;
  184         BUG_ON(!inode);
  185 
  186         end_index = inode->i_size >> PAGE_CACHE_SHIFT;
  187 
  188         /* easy case */
  189         if (page->index < end_index)
  190                 goto do_it;
  191         /* things got complicated... */
  192         offset = inode->i_size & (PAGE_CACHE_SIZE-1);
  193         /* OK, are we completely out? */
  194         if (page->index >= end_index+1 || !offset)
  195                 return 0; /* truncated - don't care */
  196 do_it:
  197         page_cache_get(page);
  198         err = smb_writepage_sync(inode, page, 0, offset);
  199         SetPageUptodate(page);
  200         unlock_page(page);
  201         page_cache_release(page);
  202         return err;
  203 }
  204 
  205 static int
  206 smb_updatepage(struct file *file, struct page *page, unsigned long offset,
  207                unsigned int count)
  208 {
  209         struct dentry *dentry = file->f_path.dentry;
  210 
  211         DEBUG1("(%s/%s %d@%lld)\n", DENTRY_PATH(dentry), count,
  212                 ((unsigned long long)page->index << PAGE_CACHE_SHIFT) + offset);
  213 
  214         return smb_writepage_sync(dentry->d_inode, page, offset, count);
  215 }
  216 
  217 static ssize_t
  218 smb_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
  219                         unsigned long nr_segs, loff_t pos)
  220 {
  221         struct file * file = iocb->ki_filp;
  222         struct dentry * dentry = file->f_path.dentry;
  223         ssize_t status;
  224 
  225         VERBOSE("file %s/%s, count=%lu@%lu\n", DENTRY_PATH(dentry),
  226                 (unsigned long) iocb->ki_left, (unsigned long) pos);
  227 
  228         status = smb_revalidate_inode(dentry);
  229         if (status) {
  230                 PARANOIA("%s/%s validation failed, error=%Zd\n",
  231                          DENTRY_PATH(dentry), status);
  232                 goto out;
  233         }
  234 
  235         VERBOSE("before read, size=%ld, flags=%x, atime=%ld\n",
  236                 (long)dentry->d_inode->i_size,
  237                 dentry->d_inode->i_flags, dentry->d_inode->i_atime.tv_sec);
  238 
  239         status = generic_file_aio_read(iocb, iov, nr_segs, pos);
  240 out:
  241         return status;
  242 }
  243 
  244 static int
  245 smb_file_mmap(struct file * file, struct vm_area_struct * vma)
  246 {
  247         struct dentry * dentry = file->f_path.dentry;
  248         int     status;
  249 
  250         VERBOSE("file %s/%s, address %lu - %lu\n",
  251                 DENTRY_PATH(dentry), vma->vm_start, vma->vm_end);
  252 
  253         status = smb_revalidate_inode(dentry);
  254         if (status) {
  255                 PARANOIA("%s/%s validation failed, error=%d\n",
  256                          DENTRY_PATH(dentry), status);
  257                 goto out;
  258         }
  259         status = generic_file_mmap(file, vma);
  260 out:
  261         return status;
  262 }
  263 
  264 static ssize_t
  265 smb_file_splice_read(struct file *file, loff_t *ppos,
  266                      struct pipe_inode_info *pipe, size_t count,
  267                      unsigned int flags)
  268 {
  269         struct dentry *dentry = file->f_path.dentry;
  270         ssize_t status;
  271 
  272         VERBOSE("file %s/%s, pos=%Ld, count=%lu\n",
  273                 DENTRY_PATH(dentry), *ppos, count);
  274 
  275         status = smb_revalidate_inode(dentry);
  276         if (status) {
  277                 PARANOIA("%s/%s validation failed, error=%Zd\n",
  278                          DENTRY_PATH(dentry), status);
  279                 goto out;
  280         }
  281         status = generic_file_splice_read(file, ppos, pipe, count, flags);
  282 out:
  283         return status;
  284 }
  285 
  286 /*
  287  * This does the "real" work of the write. The generic routine has
  288  * allocated the page, locked it, done all the page alignment stuff
  289  * calculations etc. Now we should just copy the data from user
  290  * space and write it back to the real medium..
  291  *
  292  * If the writer ends up delaying the write, the writer needs to
  293  * increment the page use counts until he is done with the page.
  294  */
  295 static int smb_write_begin(struct file *file, struct address_space *mapping,
  296                         loff_t pos, unsigned len, unsigned flags,
  297                         struct page **pagep, void **fsdata)
  298 {
  299         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
  300         *pagep = grab_cache_page_write_begin(mapping, index, flags);
  301         if (!*pagep)
  302                 return -ENOMEM;
  303         return 0;
  304 }
  305 
  306 static int smb_write_end(struct file *file, struct address_space *mapping,
  307                         loff_t pos, unsigned len, unsigned copied,
  308                         struct page *page, void *fsdata)
  309 {
  310         int status;
  311         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  312 
  313         lock_kernel();
  314         status = smb_updatepage(file, page, offset, copied);
  315         unlock_kernel();
  316 
  317         if (!status) {
  318                 if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE)
  319                         SetPageUptodate(page);
  320                 status = copied;
  321         }
  322 
  323         unlock_page(page);
  324         page_cache_release(page);
  325 
  326         return status;
  327 }
  328 
  329 const struct address_space_operations smb_file_aops = {
  330         .readpage = smb_readpage,
  331         .writepage = smb_writepage,
  332         .write_begin = smb_write_begin,
  333         .write_end = smb_write_end,
  334 };
  335 
  336 /* 
  337  * Write to a file (through the page cache).
  338  */
  339 static ssize_t
  340 smb_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
  341                                unsigned long nr_segs, loff_t pos)
  342 {
  343         struct file * file = iocb->ki_filp;
  344         struct dentry * dentry = file->f_path.dentry;
  345         ssize_t result;
  346 
  347         VERBOSE("file %s/%s, count=%lu@%lu\n",
  348                 DENTRY_PATH(dentry),
  349                 (unsigned long) iocb->ki_left, (unsigned long) pos);
  350 
  351         result = smb_revalidate_inode(dentry);
  352         if (result) {
  353                 PARANOIA("%s/%s validation failed, error=%Zd\n",
  354                          DENTRY_PATH(dentry), result);
  355                 goto out;
  356         }
  357 
  358         result = smb_open(dentry, SMB_O_WRONLY);
  359         if (result)
  360                 goto out;
  361 
  362         if (iocb->ki_left > 0) {
  363                 result = generic_file_aio_write(iocb, iov, nr_segs, pos);
  364                 VERBOSE("pos=%ld, size=%ld, mtime=%ld, atime=%ld\n",
  365                         (long) file->f_pos, (long) dentry->d_inode->i_size,
  366                         dentry->d_inode->i_mtime.tv_sec,
  367                         dentry->d_inode->i_atime.tv_sec);
  368         }
  369 out:
  370         return result;
  371 }
  372 
  373 static int
  374 smb_file_open(struct inode *inode, struct file * file)
  375 {
  376         int result;
  377         struct dentry *dentry = file->f_path.dentry;
  378         int smb_mode = (file->f_mode & O_ACCMODE) - 1;
  379 
  380         lock_kernel();
  381         result = smb_open(dentry, smb_mode);
  382         if (result)
  383                 goto out;
  384         SMB_I(inode)->openers++;
  385 out:
  386         unlock_kernel();
  387         return result;
  388 }
  389 
  390 static int
  391 smb_file_release(struct inode *inode, struct file * file)
  392 {
  393         lock_kernel();
  394         if (!--SMB_I(inode)->openers) {
  395                 /* We must flush any dirty pages now as we won't be able to
  396                    write anything after close. mmap can trigger this.
  397                    "openers" should perhaps include mmap'ers ... */
  398                 filemap_write_and_wait(inode->i_mapping);
  399                 smb_close(inode);
  400         }
  401         unlock_kernel();
  402         return 0;
  403 }
  404 
  405 /*
  406  * Check whether the required access is compatible with
  407  * an inode's permission. SMB doesn't recognize superuser
  408  * privileges, so we need our own check for this.
  409  */
  410 static int
  411 smb_file_permission(struct inode *inode, int mask)
  412 {
  413         int mode = inode->i_mode;
  414         int error = 0;
  415 
  416         VERBOSE("mode=%x, mask=%x\n", mode, mask);
  417 
  418         /* Look at user permissions */
  419         mode >>= 6;
  420         if (mask & ~mode & (MAY_READ | MAY_WRITE | MAY_EXEC))
  421                 error = -EACCES;
  422         return error;
  423 }
  424 
  425 static loff_t smb_remote_llseek(struct file *file, loff_t offset, int origin)
  426 {
  427         loff_t ret;
  428         lock_kernel();
  429         ret = generic_file_llseek_unlocked(file, offset, origin);
  430         unlock_kernel();
  431         return ret;
  432 }
  433 
  434 const struct file_operations smb_file_operations =
  435 {
  436         .llseek         = smb_remote_llseek,
  437         .read           = do_sync_read,
  438         .aio_read       = smb_file_aio_read,
  439         .write          = do_sync_write,
  440         .aio_write      = smb_file_aio_write,
  441         .unlocked_ioctl = smb_ioctl,
  442         .mmap           = smb_file_mmap,
  443         .open           = smb_file_open,
  444         .release        = smb_file_release,
  445         .fsync          = smb_fsync,
  446         .splice_read    = smb_file_splice_read,
  447 };
  448 
  449 const struct inode_operations smb_file_inode_operations =
  450 {
  451         .permission     = smb_file_permission,
  452         .getattr        = smb_getattr,
  453         .setattr        = smb_notify_change,
  454 };
Cache object: 7be0c623752e5c950c055d43f63a72fd
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/fs/smbfs/file.c

FreeBSD/Linux Kernel Cross Reference
sys/fs/smbfs/file.c
