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Diffstat (limited to 'fs/ext4/file.c')
-rw-r--r--fs/ext4/file.c153
1 files changed, 77 insertions, 76 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 063fc1538355..4e8bc284ec0e 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -57,7 +57,7 @@ static int ext4_release_file(struct inode *inode, struct file *filp)
return 0;
}
-void ext4_unwritten_wait(struct inode *inode)
+static void ext4_unwritten_wait(struct inode *inode)
{
wait_queue_head_t *wq = ext4_ioend_wq(inode);
@@ -92,58 +92,91 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
}
static ssize_t
-ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
struct file *file = iocb->ki_filp;
- struct inode *inode = file->f_mapping->host;
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct mutex *aio_mutex = NULL;
struct blk_plug plug;
- int unaligned_aio = 0;
- ssize_t ret;
+ int o_direct = file->f_flags & O_DIRECT;
int overwrite = 0;
size_t length = iov_length(iov, nr_segs);
+ ssize_t ret;
- if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
- !is_sync_kiocb(iocb))
- unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
+ BUG_ON(iocb->ki_pos != pos);
- /* Unaligned direct AIO must be serialized; see comment above */
- if (unaligned_aio) {
- mutex_lock(ext4_aio_mutex(inode));
+ /*
+ * Unaligned direct AIO must be serialized; see comment above
+ * In the case of O_APPEND, assume that we must always serialize
+ */
+ if (o_direct &&
+ ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
+ !is_sync_kiocb(iocb) &&
+ (file->f_flags & O_APPEND ||
+ ext4_unaligned_aio(inode, iov, nr_segs, pos))) {
+ aio_mutex = ext4_aio_mutex(inode);
+ mutex_lock(aio_mutex);
ext4_unwritten_wait(inode);
}
- BUG_ON(iocb->ki_pos != pos);
-
mutex_lock(&inode->i_mutex);
- blk_start_plug(&plug);
+ if (file->f_flags & O_APPEND)
+ iocb->ki_pos = pos = i_size_read(inode);
+
+ /*
+ * If we have encountered a bitmap-format file, the size limit
+ * is smaller than s_maxbytes, which is for extent-mapped files.
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- iocb->private = &overwrite;
+ if ((pos > sbi->s_bitmap_maxbytes) ||
+ (pos == sbi->s_bitmap_maxbytes && length > 0)) {
+ mutex_unlock(&inode->i_mutex);
+ ret = -EFBIG;
+ goto errout;
+ }
- /* check whether we do a DIO overwrite or not */
- if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
- !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
- struct ext4_map_blocks map;
- unsigned int blkbits = inode->i_blkbits;
- int err, len;
+ if (pos + length > sbi->s_bitmap_maxbytes) {
+ nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+ sbi->s_bitmap_maxbytes - pos);
+ }
+ }
- map.m_lblk = pos >> blkbits;
- map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
- - map.m_lblk;
- len = map.m_len;
+ if (o_direct) {
+ blk_start_plug(&plug);
- err = ext4_map_blocks(NULL, inode, &map, 0);
- /*
- * 'err==len' means that all of blocks has been preallocated no
- * matter they are initialized or not. For excluding
- * uninitialized extents, we need to check m_flags. There are
- * two conditions that indicate for initialized extents.
- * 1) If we hit extent cache, EXT4_MAP_MAPPED flag is returned;
- * 2) If we do a real lookup, non-flags are returned.
- * So we should check these two conditions.
- */
- if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
- overwrite = 1;
+ iocb->private = &overwrite;
+
+ /* check whether we do a DIO overwrite or not */
+ if (ext4_should_dioread_nolock(inode) && !aio_mutex &&
+ !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
+ struct ext4_map_blocks map;
+ unsigned int blkbits = inode->i_blkbits;
+ int err, len;
+
+ map.m_lblk = pos >> blkbits;
+ map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
+ - map.m_lblk;
+ len = map.m_len;
+
+ err = ext4_map_blocks(NULL, inode, &map, 0);
+ /*
+ * 'err==len' means that all of blocks has
+ * been preallocated no matter they are
+ * initialized or not. For excluding
+ * unwritten extents, we need to check
+ * m_flags. There are two conditions that
+ * indicate for initialized extents. 1) If we
+ * hit extent cache, EXT4_MAP_MAPPED flag is
+ * returned; 2) If we do a real lookup,
+ * non-flags are returned. So we should check
+ * these two conditions.
+ */
+ if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
+ overwrite = 1;
+ }
}
ret = __generic_file_aio_write(iocb, iov, nr_segs);
@@ -156,45 +189,12 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
if (err < 0)
ret = err;
}
- blk_finish_plug(&plug);
-
- if (unaligned_aio)
- mutex_unlock(ext4_aio_mutex(inode));
-
- return ret;
-}
-
-static ssize_t
-ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- ssize_t ret;
-
- /*
- * If we have encountered a bitmap-format file, the size limit
- * is smaller than s_maxbytes, which is for extent-mapped files.
- */
-
- if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
- struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- size_t length = iov_length(iov, nr_segs);
-
- if ((pos > sbi->s_bitmap_maxbytes ||
- (pos == sbi->s_bitmap_maxbytes && length > 0)))
- return -EFBIG;
-
- if (pos + length > sbi->s_bitmap_maxbytes) {
- nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
- sbi->s_bitmap_maxbytes - pos);
- }
- }
-
- if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
- ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
- else
- ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+ if (o_direct)
+ blk_finish_plug(&plug);
+errout:
+ if (aio_mutex)
+ mutex_unlock(aio_mutex);
return ret;
}
@@ -244,6 +244,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
+ BUFFER_TRACE(sbi->s_sbh, "get_write_access");
err = ext4_journal_get_write_access(handle, sbi->s_sbh);
if (err) {
ext4_journal_stop(handle);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-26 08:57:40 +0000