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-rw-r--r--fs/btrfs/file.c169
1 files changed, 162 insertions, 7 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index fa4ef18b66b1..59cbdb120ad0 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1452,7 +1452,7 @@ int btrfs_release_file(struct inode *inode, struct file *filp)
* important optimization for directories because holding the mutex prevents
* new operations on the dir while we write to disk.
*/
-int btrfs_sync_file(struct file *file, int datasync)
+int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
@@ -1462,9 +1462,13 @@ int btrfs_sync_file(struct file *file, int datasync)
trace_btrfs_sync_file(file, datasync);
+ ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (ret)
+ return ret;
+ mutex_lock(&inode->i_mutex);
+
/* we wait first, since the writeback may change the inode */
root->log_batch++;
- /* the VFS called filemap_fdatawrite for us */
btrfs_wait_ordered_range(inode, 0, (u64)-1);
root->log_batch++;
@@ -1472,8 +1476,10 @@ int btrfs_sync_file(struct file *file, int datasync)
* check the transaction that last modified this inode
* and see if its already been committed
*/
- if (!BTRFS_I(inode)->last_trans)
+ if (!BTRFS_I(inode)->last_trans) {
+ mutex_unlock(&inode->i_mutex);
goto out;
+ }
/*
* if the last transaction that changed this file was before
@@ -1484,6 +1490,7 @@ int btrfs_sync_file(struct file *file, int datasync)
if (BTRFS_I(inode)->last_trans <=
root->fs_info->last_trans_committed) {
BTRFS_I(inode)->last_trans = 0;
+ mutex_unlock(&inode->i_mutex);
goto out;
}
@@ -1496,12 +1503,15 @@ int btrfs_sync_file(struct file *file, int datasync)
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
+ mutex_unlock(&inode->i_mutex);
goto out;
}
ret = btrfs_log_dentry_safe(trans, root, dentry);
- if (ret < 0)
+ if (ret < 0) {
+ mutex_unlock(&inode->i_mutex);
goto out;
+ }
/* we've logged all the items and now have a consistent
* version of the file in the log. It is possible that
@@ -1513,7 +1523,7 @@ int btrfs_sync_file(struct file *file, int datasync)
* file again, but that will end up using the synchronization
* inside btrfs_sync_log to keep things safe.
*/
- mutex_unlock(&dentry->d_inode->i_mutex);
+ mutex_unlock(&inode->i_mutex);
if (ret != BTRFS_NO_LOG_SYNC) {
if (ret > 0) {
@@ -1528,7 +1538,6 @@ int btrfs_sync_file(struct file *file, int datasync)
} else {
ret = btrfs_end_transaction(trans, root);
}
- mutex_lock(&dentry->d_inode->i_mutex);
out:
return ret > 0 ? -EIO : ret;
}
@@ -1664,8 +1673,154 @@ out:
return ret;
}
+static int find_desired_extent(struct inode *inode, loff_t *offset, int origin)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map *em;
+ struct extent_state *cached_state = NULL;
+ u64 lockstart = *offset;
+ u64 lockend = i_size_read(inode);
+ u64 start = *offset;
+ u64 orig_start = *offset;
+ u64 len = i_size_read(inode);
+ u64 last_end = 0;
+ int ret = 0;
+
+ lockend = max_t(u64, root->sectorsize, lockend);
+ if (lockend <= lockstart)
+ lockend = lockstart + root->sectorsize;
+
+ len = lockend - lockstart + 1;
+
+ len = max_t(u64, len, root->sectorsize);
+ if (inode->i_size == 0)
+ return -ENXIO;
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
+ &cached_state, GFP_NOFS);
+
+ /*
+ * Delalloc is such a pain. If we have a hole and we have pending
+ * delalloc for a portion of the hole we will get back a hole that
+ * exists for the entire range since it hasn't been actually written
+ * yet. So to take care of this case we need to look for an extent just
+ * before the position we want in case there is outstanding delalloc
+ * going on here.
+ */
+ if (origin == SEEK_HOLE && start != 0) {
+ if (start <= root->sectorsize)
+ em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
+ root->sectorsize, 0);
+ else
+ em = btrfs_get_extent_fiemap(inode, NULL, 0,
+ start - root->sectorsize,
+ root->sectorsize, 0);
+ if (IS_ERR(em)) {
+ ret = -ENXIO;
+ goto out;
+ }
+ last_end = em->start + em->len;
+ if (em->block_start == EXTENT_MAP_DELALLOC)
+ last_end = min_t(u64, last_end, inode->i_size);
+ free_extent_map(em);
+ }
+
+ while (1) {
+ em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
+ if (IS_ERR(em)) {
+ ret = -ENXIO;
+ break;
+ }
+
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ if (last_end <= orig_start) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ }
+
+ if (origin == SEEK_HOLE) {
+ *offset = start;
+ free_extent_map(em);
+ break;
+ }
+ } else {
+ if (origin == SEEK_DATA) {
+ if (em->block_start == EXTENT_MAP_DELALLOC) {
+ if (start >= inode->i_size) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ }
+
+ *offset = start;
+ free_extent_map(em);
+ break;
+ }
+ }
+
+ start = em->start + em->len;
+ last_end = em->start + em->len;
+
+ if (em->block_start == EXTENT_MAP_DELALLOC)
+ last_end = min_t(u64, last_end, inode->i_size);
+
+ if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
+ free_extent_map(em);
+ ret = -ENXIO;
+ break;
+ }
+ free_extent_map(em);
+ cond_resched();
+ }
+ if (!ret)
+ *offset = min(*offset, inode->i_size);
+out:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ &cached_state, GFP_NOFS);
+ return ret;
+}
+
+static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
+{
+ struct inode *inode = file->f_mapping->host;
+ int ret;
+
+ mutex_lock(&inode->i_mutex);
+ switch (origin) {
+ case SEEK_END:
+ case SEEK_CUR:
+ offset = generic_file_llseek_unlocked(file, offset, origin);
+ goto out;
+ case SEEK_DATA:
+ case SEEK_HOLE:
+ ret = find_desired_extent(inode, &offset, origin);
+ if (ret) {
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+ }
+ }
+
+ if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET))
+ return -EINVAL;
+ if (offset > inode->i_sb->s_maxbytes)
+ return -EINVAL;
+
+ /* Special lock needed here? */
+ if (offset != file->f_pos) {
+ file->f_pos = offset;
+ file->f_version = 0;
+ }
+out:
+ mutex_unlock(&inode->i_mutex);
+ return offset;
+}
+
const struct file_operations btrfs_file_operations = {
- .llseek = generic_file_llseek,
+ .llseek = btrfs_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 13:02:58 +0000