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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /fs/ext4/fsync.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'fs/ext4/fsync.c')
-rw-r--r-- | fs/ext4/fsync.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c new file mode 100644 index 00000000..bb6c7d81 --- /dev/null +++ b/fs/ext4/fsync.c @@ -0,0 +1,271 @@ +/* + * linux/fs/ext4/fsync.c + * + * Copyright (C) 1993 Stephen Tweedie (sct@redhat.com) + * from + * Copyright (C) 1992 Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * from + * linux/fs/minix/truncate.c Copyright (C) 1991, 1992 Linus Torvalds + * + * ext4fs fsync primitive + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + * + * Removed unnecessary code duplication for little endian machines + * and excessive __inline__s. + * Andi Kleen, 1997 + * + * Major simplications and cleanup - we only need to do the metadata, because + * we can depend on generic_block_fdatasync() to sync the data blocks. + */ + +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include <linux/writeback.h> +#include <linux/jbd2.h> +#include <linux/blkdev.h> + +#include "ext4.h" +#include "ext4_jbd2.h" + +#include <trace/events/ext4.h> + +static void dump_completed_IO(struct inode * inode) +{ +#ifdef EXT4FS_DEBUG + struct list_head *cur, *before, *after; + ext4_io_end_t *io, *io0, *io1; + unsigned long flags; + + if (list_empty(&EXT4_I(inode)->i_completed_io_list)){ + ext4_debug("inode %lu completed_io list is empty\n", inode->i_ino); + return; + } + + ext4_debug("Dump inode %lu completed_io list \n", inode->i_ino); + spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); + list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list){ + cur = &io->list; + before = cur->prev; + io0 = container_of(before, ext4_io_end_t, list); + after = cur->next; + io1 = container_of(after, ext4_io_end_t, list); + + ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", + io, inode->i_ino, io0, io1); + } + spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags); +#endif +} + +/* + * This function is called from ext4_sync_file(). + * + * When IO is completed, the work to convert unwritten extents to + * written is queued on workqueue but may not get immediately + * scheduled. When fsync is called, we need to ensure the + * conversion is complete before fsync returns. + * The inode keeps track of a list of pending/completed IO that + * might needs to do the conversion. This function walks through + * the list and convert the related unwritten extents for completed IO + * to written. + * The function return the number of pending IOs on success. + */ +int ext4_flush_completed_IO(struct inode *inode) +{ + ext4_io_end_t *io; + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned long flags; + int ret = 0; + int ret2 = 0; + + dump_completed_IO(inode); + spin_lock_irqsave(&ei->i_completed_io_lock, flags); + while (!list_empty(&ei->i_completed_io_list)){ + io = list_entry(ei->i_completed_io_list.next, + ext4_io_end_t, list); + list_del_init(&io->list); + io->flag |= EXT4_IO_END_IN_FSYNC; + /* + * Calling ext4_end_io_nolock() to convert completed + * IO to written. + * + * When ext4_sync_file() is called, run_queue() may already + * about to flush the work corresponding to this io structure. + * It will be upset if it founds the io structure related + * to the work-to-be schedule is freed. + * + * Thus we need to keep the io structure still valid here after + * conversion finished. The io structure has a flag to + * avoid double converting from both fsync and background work + * queue work. + */ + spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); + ret = ext4_end_io_nolock(io); + if (ret < 0) + ret2 = ret; + spin_lock_irqsave(&ei->i_completed_io_lock, flags); + io->flag &= ~EXT4_IO_END_IN_FSYNC; + } + spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); + return (ret2 < 0) ? ret2 : 0; +} + +/* + * If we're not journaling and this is a just-created file, we have to + * sync our parent directory (if it was freshly created) since + * otherwise it will only be written by writeback, leaving a huge + * window during which a crash may lose the file. This may apply for + * the parent directory's parent as well, and so on recursively, if + * they are also freshly created. + */ +static int ext4_sync_parent(struct inode *inode) +{ + struct writeback_control wbc; + struct dentry *dentry = NULL; + struct inode *next; + int ret = 0; + + if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) + return 0; + inode = igrab(inode); + while (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) { + ext4_clear_inode_state(inode, EXT4_STATE_NEWENTRY); + dentry = NULL; + spin_lock(&inode->i_lock); + if (!list_empty(&inode->i_dentry)) { + dentry = list_first_entry(&inode->i_dentry, + struct dentry, d_alias); + dget(dentry); + } + spin_unlock(&inode->i_lock); + if (!dentry) + break; + next = igrab(dentry->d_parent->d_inode); + dput(dentry); + if (!next) + break; + iput(inode); + inode = next; + ret = sync_mapping_buffers(inode->i_mapping); + if (ret) + break; + memset(&wbc, 0, sizeof(wbc)); + wbc.sync_mode = WB_SYNC_ALL; + wbc.nr_to_write = 0; /* only write out the inode */ + ret = sync_inode(inode, &wbc); + if (ret) + break; + } + iput(inode); + return ret; +} + +/** + * __sync_file - generic_file_fsync without the locking and filemap_write + * @inode: inode to sync + * @datasync: only sync essential metadata if true + * + * This is just generic_file_fsync without the locking. This is needed for + * nojournal mode to make sure this inodes data/metadata makes it to disk + * properly. The i_mutex should be held already. + */ +static int __sync_inode(struct inode *inode, int datasync) +{ + int err; + int ret; + + ret = sync_mapping_buffers(inode->i_mapping); + if (!(inode->i_state & I_DIRTY)) + return ret; + if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) + return ret; + + err = sync_inode_metadata(inode, 1); + if (ret == 0) + ret = err; + return ret; +} + +/* + * akpm: A new design for ext4_sync_file(). + * + * This is only called from sys_fsync(), sys_fdatasync() and sys_msync(). + * There cannot be a transaction open by this task. + * Another task could have dirtied this inode. Its data can be in any + * state in the journalling system. + * + * What we do is just kick off a commit and wait on it. This will snapshot the + * inode to disk. + * + * i_mutex lock is held when entering and exiting this function + */ + +int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct inode *inode = file->f_mapping->host; + struct ext4_inode_info *ei = EXT4_I(inode); + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + int ret; + tid_t commit_tid; + bool needs_barrier = false; + + J_ASSERT(ext4_journal_current_handle() == NULL); + + trace_ext4_sync_file_enter(file, datasync); + + ret = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (ret) + return ret; + mutex_lock(&inode->i_mutex); + + if (inode->i_sb->s_flags & MS_RDONLY) + goto out; + + ret = ext4_flush_completed_IO(inode); + if (ret < 0) + goto out; + + if (!journal) { + ret = __sync_inode(inode, datasync); + if (!ret && !list_empty(&inode->i_dentry)) + ret = ext4_sync_parent(inode); + goto out; + } + + /* + * data=writeback,ordered: + * The caller's filemap_fdatawrite()/wait will sync the data. + * Metadata is in the journal, we wait for proper transaction to + * commit here. + * + * data=journal: + * filemap_fdatawrite won't do anything (the buffers are clean). + * ext4_force_commit will write the file data into the journal and + * will wait on that. + * filemap_fdatawait() will encounter a ton of newly-dirtied pages + * (they were dirtied by commit). But that's OK - the blocks are + * safe in-journal, which is all fsync() needs to ensure. + */ + if (ext4_should_journal_data(inode)) { + ret = ext4_force_commit(inode->i_sb); + goto out; + } + + commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; + if (journal->j_flags & JBD2_BARRIER && + !jbd2_trans_will_send_data_barrier(journal, commit_tid)) + needs_barrier = true; + jbd2_log_start_commit(journal, commit_tid); + ret = jbd2_log_wait_commit(journal, commit_tid); + if (needs_barrier) + blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); + out: + mutex_unlock(&inode->i_mutex); + trace_ext4_sync_file_exit(inode, ret); + return ret; +} |