X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsync.c;h=418727a2a2390f435d68b1fad91dede88dc4c17f;hb=bdeef61cd053b6a88be7d2c82fd43e12f8c9f75e;hp=66f210476f404fd84edfdc9fc8ed03a5f9bcae48;hpb=d8a8559cd7a9ccac98d5f6f13297a2ff68a43627;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/sync.c b/fs/sync.c index 66f2104..418727a 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -27,6 +27,13 @@ */ static int __sync_filesystem(struct super_block *sb, int wait) { + /* + * This should be safe, as we require bdi backing to actually + * write out data in the first place + */ + if (!sb->s_bdi) + return 0; + /* Avoid doing twice syncing and cache pruning for quota sync */ if (!wait) { writeout_quota_sb(sb, -1); @@ -101,7 +108,7 @@ restart: spin_unlock(&sb_lock); down_read(&sb->s_umount); - if (!(sb->s_flags & MS_RDONLY) && sb->s_root) + if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi) __sync_filesystem(sb, wait); up_read(&sb->s_umount); @@ -120,7 +127,7 @@ restart: */ SYSCALL_DEFINE0(sync) { - wakeup_pdflush(0); + wakeup_flusher_threads(0); sync_filesystems(0); sync_filesystems(1); if (unlikely(laptop_mode)) @@ -176,21 +183,26 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync) ret = err; return ret; } +EXPORT_SYMBOL(file_fsync); /** - * vfs_fsync - perform a fsync or fdatasync on a file + * vfs_fsync_range - helper to sync a range of data & metadata to disk * @file: file to sync * @dentry: dentry of @file - * @data: only perform a fdatasync operation + * @start: offset in bytes of the beginning of data range to sync + * @end: offset in bytes of the end of data range (inclusive) + * @datasync: perform only datasync * - * Write back data and metadata for @file to disk. If @datasync is - * set only metadata needed to access modified file data is written. + * Write back data in range @start..@end and metadata for @file to disk. If + * @datasync is set only metadata needed to access modified file data is + * written. * * In case this function is called from nfsd @file may be %NULL and * only @dentry is set. This can only happen when the filesystem * implements the export_operations API. */ -int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) +int vfs_fsync_range(struct file *file, struct dentry *dentry, loff_t start, + loff_t end, int datasync) { const struct file_operations *fop; struct address_space *mapping; @@ -214,7 +226,7 @@ int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) goto out; } - ret = filemap_fdatawrite(mapping); + ret = filemap_write_and_wait_range(mapping, start, end); /* * We need to protect against concurrent writers, which could cause @@ -225,12 +237,29 @@ int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) if (!ret) ret = err; mutex_unlock(&mapping->host->i_mutex); - err = filemap_fdatawait(mapping); - if (!ret) - ret = err; + out: return ret; } +EXPORT_SYMBOL(vfs_fsync_range); + +/** + * vfs_fsync - perform a fsync or fdatasync on a file + * @file: file to sync + * @dentry: dentry of @file + * @datasync: only perform a fdatasync operation + * + * Write back data and metadata for @file to disk. If @datasync is + * set only metadata needed to access modified file data is written. + * + * In case this function is called from nfsd @file may be %NULL and + * only @dentry is set. This can only happen when the filesystem + * implements the export_operations API. + */ +int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + return vfs_fsync_range(file, dentry, 0, LLONG_MAX, datasync); +} EXPORT_SYMBOL(vfs_fsync); static int do_fsync(unsigned int fd, int datasync) @@ -256,6 +285,24 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd) return do_fsync(fd, 1); } +/** + * generic_write_sync - perform syncing after a write if file / inode is sync + * @file: file to which the write happened + * @pos: offset where the write started + * @count: length of the write + * + * This is just a simple wrapper about our general syncing function. + */ +int generic_write_sync(struct file *file, loff_t pos, loff_t count) +{ + if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host)) + return 0; + return vfs_fsync_range(file, file->f_path.dentry, pos, + pos + count - 1, + (file->f_flags & __O_SYNC) ? 0 : 1); +} +EXPORT_SYMBOL(generic_write_sync); + /* * sys_sync_file_range() permits finely controlled syncing over a segment of * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is @@ -308,6 +355,7 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes, { int ret; struct file *file; + struct address_space *mapping; loff_t endbyte; /* inclusive */ int fput_needed; umode_t i_mode; @@ -358,7 +406,28 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes, !S_ISLNK(i_mode)) goto out_put; - ret = do_sync_mapping_range(file->f_mapping, offset, endbyte, flags); + mapping = file->f_mapping; + if (!mapping) { + ret = -EINVAL; + goto out_put; + } + + ret = 0; + if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) { + ret = filemap_fdatawait_range(mapping, offset, endbyte); + if (ret < 0) + goto out_put; + } + + if (flags & SYNC_FILE_RANGE_WRITE) { + ret = filemap_fdatawrite_range(mapping, offset, endbyte); + if (ret < 0) + goto out_put; + } + + if (flags & SYNC_FILE_RANGE_WAIT_AFTER) + ret = filemap_fdatawait_range(mapping, offset, endbyte); + out_put: fput_light(file, fput_needed); out: @@ -390,42 +459,3 @@ asmlinkage long SyS_sync_file_range2(long fd, long flags, } SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2); #endif - -/* - * `endbyte' is inclusive - */ -int do_sync_mapping_range(struct address_space *mapping, loff_t offset, - loff_t endbyte, unsigned int flags) -{ - int ret; - - if (!mapping) { - ret = -EINVAL; - goto out; - } - - ret = 0; - if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) { - ret = wait_on_page_writeback_range(mapping, - offset >> PAGE_CACHE_SHIFT, - endbyte >> PAGE_CACHE_SHIFT); - if (ret < 0) - goto out; - } - - if (flags & SYNC_FILE_RANGE_WRITE) { - ret = __filemap_fdatawrite_range(mapping, offset, endbyte, - WB_SYNC_ALL); - if (ret < 0) - goto out; - } - - if (flags & SYNC_FILE_RANGE_WAIT_AFTER) { - ret = wait_on_page_writeback_range(mapping, - offset >> PAGE_CACHE_SHIFT, - endbyte >> PAGE_CACHE_SHIFT); - } -out: - return ret; -} -EXPORT_SYMBOL_GPL(do_sync_mapping_range);