lkml.org 
[lkml]   [2014]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v11 10/21] dax,ext2: Replace xip_truncate_page with dax_truncate_page
    Date
    It takes a get_block parameter just like nobh_truncate_page() and
    block_truncate_page()

    Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
    ---
    fs/dax.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
    fs/ext2/inode.c | 2 +-
    include/linux/fs.h | 4 ++--
    mm/filemap_xip.c | 40 ----------------------------------------
    4 files changed, 47 insertions(+), 43 deletions(-)

    diff --git a/fs/dax.c b/fs/dax.c
    index ac5d3a6..6801be7 100644
    --- a/fs/dax.c
    +++ b/fs/dax.c
    @@ -460,3 +460,47 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
    return result;
    }
    EXPORT_SYMBOL_GPL(dax_fault);
    +
    +/**
    + * dax_truncate_page - handle a partial page being truncated in a DAX file
    + * @inode: The file being truncated
    + * @from: The file offset that is being truncated to
    + * @get_block: The filesystem method used to translate file offsets to blocks
    + *
    + * Similar to block_truncate_page(), this function can be called by a
    + * filesystem when it is truncating an DAX file to handle the partial page.
    + *
    + * We work in terms of PAGE_CACHE_SIZE here for commonality with
    + * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem
    + * took care of disposing of the unnecessary blocks. Even if the filesystem
    + * block size is smaller than PAGE_SIZE, we have to zero the rest of the page
    + * since the file might be mmaped.
    + */
    +int dax_truncate_page(struct inode *inode, loff_t from, get_block_t get_block)
    +{
    + struct buffer_head bh;
    + pgoff_t index = from >> PAGE_CACHE_SHIFT;
    + unsigned offset = from & (PAGE_CACHE_SIZE-1);
    + unsigned length = PAGE_CACHE_ALIGN(from) - from;
    + int err;
    +
    + /* Block boundary? Nothing to do */
    + if (!length)
    + return 0;
    +
    + memset(&bh, 0, sizeof(bh));
    + bh.b_size = PAGE_CACHE_SIZE;
    + err = get_block(inode, index, &bh, 0);
    + if (err < 0)
    + return err;
    + if (buffer_written(&bh)) {
    + void *addr;
    + err = dax_get_addr(&bh, &addr, inode->i_blkbits);
    + if (err < 0)
    + return err;
    + memset(addr + offset, 0, length);
    + }
    +
    + return 0;
    +}
    +EXPORT_SYMBOL_GPL(dax_truncate_page);
    diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
    index 52978b8..5ac0a34 100644
    --- a/fs/ext2/inode.c
    +++ b/fs/ext2/inode.c
    @@ -1210,7 +1210,7 @@ static int ext2_setsize(struct inode *inode, loff_t newsize)
    inode_dio_wait(inode);

    if (IS_DAX(inode))
    - error = xip_truncate_page(inode->i_mapping, newsize);
    + error = dax_truncate_page(inode, newsize, ext2_get_block);
    else if (test_opt(inode->i_sb, NOBH))
    error = nobh_truncate_page(inode->i_mapping,
    newsize, ext2_get_block);
    diff --git a/include/linux/fs.h b/include/linux/fs.h
    index 338f04b..eee848d 100644
    --- a/include/linux/fs.h
    +++ b/include/linux/fs.h
    @@ -2492,7 +2492,7 @@ extern int nonseekable_open(struct inode * inode, struct file * filp);

    #ifdef CONFIG_FS_XIP
    int dax_clear_blocks(struct inode *, sector_t block, long size);
    -extern int xip_truncate_page(struct address_space *mapping, loff_t from);
    +int dax_truncate_page(struct inode *, loff_t from, get_block_t);
    ssize_t dax_do_io(int rw, struct kiocb *, struct inode *, struct iov_iter *,
    loff_t, get_block_t, dio_iodone_t, int flags);
    int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
    @@ -2503,7 +2503,7 @@ static inline int dax_clear_blocks(struct inode *i, sector_t blk, long sz)
    return 0;
    }

    -static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
    +static inline int dax_truncate_page(struct inode *i, loff_t frm, get_block_t gb)
    {
    return 0;
    }
    diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
    index 9dd45f3..6316578 100644
    --- a/mm/filemap_xip.c
    +++ b/mm/filemap_xip.c
    @@ -21,43 +21,3 @@
    #include <asm/tlbflush.h>
    #include <asm/io.h>

    -/*
    - * truncate a page used for execute in place
    - * functionality is analog to block_truncate_page but does use get_xip_mem
    - * to get the page instead of page cache
    - */
    -int
    -xip_truncate_page(struct address_space *mapping, loff_t from)
    -{
    - pgoff_t index = from >> PAGE_CACHE_SHIFT;
    - unsigned offset = from & (PAGE_CACHE_SIZE-1);
    - unsigned blocksize;
    - unsigned length;
    - void *xip_mem;
    - unsigned long xip_pfn;
    - int err;
    -
    - BUG_ON(!mapping->a_ops->get_xip_mem);
    -
    - blocksize = 1 << mapping->host->i_blkbits;
    - length = offset & (blocksize - 1);
    -
    - /* Block boundary? Nothing to do */
    - if (!length)
    - return 0;
    -
    - length = blocksize - length;
    -
    - err = mapping->a_ops->get_xip_mem(mapping, index, 0,
    - &xip_mem, &xip_pfn);
    - if (unlikely(err)) {
    - if (err == -ENODATA)
    - /* Hole? No need to truncate */
    - return 0;
    - else
    - return err;
    - }
    - memset(xip_mem + offset, 0, length);
    - return 0;
    -}
    -EXPORT_SYMBOL_GPL(xip_truncate_page);
    --
    2.1.0


    \
     
     \ /
      Last update: 2014-09-25 23:01    [W:3.144 / U:0.184 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site