diff options
Diffstat (limited to 'fs/fat/inode.c')
| -rw-r--r-- | fs/fat/inode.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 5d4513cb1b3c..f49de9379bcd 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -152,11 +152,65 @@ static void fat_write_failed(struct address_space *mapping, loff_t to) } } +static int fat_zero_falloc_area(struct file *file, + struct address_space *mapping, loff_t pos) +{ + struct page *page; + struct inode *inode = mapping->host; + loff_t curpos = i_size_read(inode); + size_t count = pos - curpos; + int err; + + do { + unsigned offset; + size_t bytes; + void *fsdata; + + offset = (curpos & (PAGE_CACHE_SIZE - 1)); + bytes = PAGE_CACHE_SIZE - offset; + bytes = min(bytes, count); + + err = pagecache_write_begin(NULL, mapping, curpos, bytes, + AOP_FLAG_UNINTERRUPTIBLE, + &page, &fsdata); + if (err) + break; + + zero_user(page, offset, bytes); + + err = pagecache_write_end(NULL, mapping, curpos, bytes, bytes, + page, fsdata); + if (err < 0) + break; + curpos += bytes; + count -= bytes; + err = 0; + } while (count); + + return err; +} + static int fat_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { int err; + loff_t mmu_private_ideal, mmu_private_actual; + loff_t size; + struct inode *inode = mapping->host; + struct super_block *sb = inode->i_sb; + + size = i_size_read(inode); + mmu_private_actual = MSDOS_I(inode)->mmu_private; + mmu_private_ideal = round_up(size, sb->s_blocksize); + if ((mmu_private_actual > mmu_private_ideal) && (pos > size)) { + err = fat_zero_falloc_area(file, mapping, pos); + if (err) { + fat_msg(sb, KERN_ERR, + "Error (%d) zeroing fallocated area", err); + return err; + } + } *pagep = NULL; err = cont_write_begin(file, mapping, pos, len, flags, |