~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/ntfs/aops.h

Version: ~ [ linux-5.8-rc4 ] ~ [ linux-5.7.7 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.50 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.131 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.187 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.229 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.229 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /**
  2  * aops.h - Defines for NTFS kernel address space operations and page cache
  3  *          handling.  Part of the Linux-NTFS project.
  4  *
  5  * Copyright (c) 2001-2004 Anton Altaparmakov
  6  * Copyright (c) 2002 Richard Russon
  7  *
  8  * This program/include file is free software; you can redistribute it and/or
  9  * modify it under the terms of the GNU General Public License as published
 10  * by the Free Software Foundation; either version 2 of the License, or
 11  * (at your option) any later version.
 12  *
 13  * This program/include file is distributed in the hope that it will be
 14  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16  * GNU General Public License for more details.
 17  *
 18  * You should have received a copy of the GNU General Public License
 19  * along with this program (in the main directory of the Linux-NTFS
 20  * distribution in the file COPYING); if not, write to the Free Software
 21  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 22  */
 23 
 24 #ifndef _LINUX_NTFS_AOPS_H
 25 #define _LINUX_NTFS_AOPS_H
 26 
 27 #include <linux/mm.h>
 28 #include <linux/highmem.h>
 29 #include <linux/pagemap.h>
 30 #include <linux/fs.h>
 31 
 32 #include "inode.h"
 33 
 34 /**
 35  * ntfs_unmap_page - release a page that was mapped using ntfs_map_page()
 36  * @page:       the page to release
 37  *
 38  * Unpin, unmap and release a page that was obtained from ntfs_map_page().
 39  */
 40 static inline void ntfs_unmap_page(struct page *page)
 41 {
 42         kunmap(page);
 43         put_page(page);
 44 }
 45 
 46 /**
 47  * ntfs_map_page - map a page into accessible memory, reading it if necessary
 48  * @mapping:    address space for which to obtain the page
 49  * @index:      index into the page cache for @mapping of the page to map
 50  *
 51  * Read a page from the page cache of the address space @mapping at position
 52  * @index, where @index is in units of PAGE_SIZE, and not in bytes.
 53  *
 54  * If the page is not in memory it is loaded from disk first using the readpage
 55  * method defined in the address space operations of @mapping and the page is
 56  * added to the page cache of @mapping in the process.
 57  *
 58  * If the page belongs to an mst protected attribute and it is marked as such
 59  * in its ntfs inode (NInoMstProtected()) the mst fixups are applied but no
 60  * error checking is performed.  This means the caller has to verify whether
 61  * the ntfs record(s) contained in the page are valid or not using one of the
 62  * ntfs_is_XXXX_record{,p}() macros, where XXXX is the record type you are
 63  * expecting to see.  (For details of the macros, see fs/ntfs/layout.h.)
 64  *
 65  * If the page is in high memory it is mapped into memory directly addressible
 66  * by the kernel.
 67  *
 68  * Finally the page count is incremented, thus pinning the page into place.
 69  *
 70  * The above means that page_address(page) can be used on all pages obtained
 71  * with ntfs_map_page() to get the kernel virtual address of the page.
 72  *
 73  * When finished with the page, the caller has to call ntfs_unmap_page() to
 74  * unpin, unmap and release the page.
 75  *
 76  * Note this does not grant exclusive access. If such is desired, the caller
 77  * must provide it independently of the ntfs_{un}map_page() calls by using
 78  * a {rw_}semaphore or other means of serialization. A spin lock cannot be
 79  * used as ntfs_map_page() can block.
 80  *
 81  * The unlocked and uptodate page is returned on success or an encoded error
 82  * on failure. Caller has to test for error using the IS_ERR() macro on the
 83  * return value. If that evaluates to 'true', the negative error code can be
 84  * obtained using PTR_ERR() on the return value of ntfs_map_page().
 85  */
 86 static inline struct page *ntfs_map_page(struct address_space *mapping,
 87                 unsigned long index)
 88 {
 89         struct page *page = read_mapping_page(mapping, index, NULL);
 90 
 91         if (!IS_ERR(page)) {
 92                 kmap(page);
 93                 if (!PageError(page))
 94                         return page;
 95                 ntfs_unmap_page(page);
 96                 return ERR_PTR(-EIO);
 97         }
 98         return page;
 99 }
100 
101 #ifdef NTFS_RW
102 
103 extern void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs);
104 
105 #endif /* NTFS_RW */
106 
107 #endif /* _LINUX_NTFS_AOPS_H */
108 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp