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author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2015-02-17 02:59:06 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-17 04:56:03 +0300 |
commit | 4c0ccfef2e9f7418a6eb0bf07a2fc8f216365b18 (patch) | |
tree | ca1c0bebddf210eab5e5428bb0416d6bfc71495b /fs/dax.c | |
parent | f7ca90b160307d63aaedab8bd451c24a182db20f (diff) | |
download | linux-4c0ccfef2e9f7418a6eb0bf07a2fc8f216365b18.tar.xz |
dax,ext2: replace xip_truncate_page with dax_truncate_page
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>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/dax.c')
-rw-r--r-- | fs/dax.c | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -462,3 +462,47 @@ 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); |