ext4: Introduce a new helper function ext4_generic_write_inline_data()

A new function, ext4_generic_write_inline_data(), is introduced
to provide a generic implementation of the common logic found in
ext4_da_write_inline_data_begin() and ext4_try_to_write_inline_data().

This function will be utilized in the subsequent two patches.

Signed-off-by: Julian Sun <sunjunchao2870@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250107045549.1837589-1-sunjunchao2870@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 3536ca7e4fccab77b8d4c8fd4cd14cbaa20e7f83..3e103e003afbc6aff9001e76b0011e19074e443f 100644 (file)
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -20,6 +20,11 @@
 #define EXT4_INLINE_DOTDOT_OFFSET      2
 #define EXT4_INLINE_DOTDOT_SIZE                4
 
+
+static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping,
+                                                struct inode *inode,
+                                                void **fsdata);
+
 static int ext4_get_inline_size(struct inode *inode)
 {
        if (EXT4_I(inode)->i_inline_off)
@@ -652,6 +657,87 @@ out_nofolio:
        return ret;
 }
 
+static int ext4_generic_write_inline_data(struct address_space *mapping,
+                                         struct inode *inode,
+                                         loff_t pos, unsigned len,
+                                         struct folio **foliop,
+                                         void **fsdata, bool da)
+{
+       int ret;
+       handle_t *handle;
+       struct folio *folio;
+       struct ext4_iloc iloc;
+       int retries = 0;
+
+       ret = ext4_get_inode_loc(inode, &iloc);
+       if (ret)
+               return ret;
+
+retry_journal:
+       handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               goto out_release_bh;
+       }
+
+       ret = ext4_prepare_inline_data(handle, inode, pos + len);
+       if (ret && ret != -ENOSPC)
+               goto out_stop_journal;
+
+       if (ret == -ENOSPC) {
+               ext4_journal_stop(handle);
+               if (!da) {
+                       brelse(iloc.bh);
+                       /* Retry inside */
+                       return ext4_convert_inline_data_to_extent(mapping, inode);
+               }
+
+               ret = ext4_da_convert_inline_data_to_extent(mapping, inode, fsdata);
+               if (ret == -ENOSPC &&
+                   ext4_should_retry_alloc(inode->i_sb, &retries))
+                       goto retry_journal;
+               goto out_release_bh;
+       }
+
+       folio = __filemap_get_folio(mapping, 0, FGP_WRITEBEGIN | FGP_NOFS,
+                                       mapping_gfp_mask(mapping));
+       if (IS_ERR(folio)) {
+               ret = PTR_ERR(folio);
+               goto out_stop_journal;
+       }
+
+       down_read(&EXT4_I(inode)->xattr_sem);
+       /* Someone else had converted it to extent */
+       if (!ext4_has_inline_data(inode)) {
+               ret = 0;
+               goto out_release_folio;
+       }
+
+       if (!folio_test_uptodate(folio)) {
+               ret = ext4_read_inline_folio(inode, folio);
+               if (ret < 0)
+                       goto out_release_folio;
+       }
+
+       ret = ext4_journal_get_write_access(handle, inode->i_sb, iloc.bh, EXT4_JTR_NONE);
+       if (ret)
+               goto out_release_folio;
+       *foliop = folio;
+       up_read(&EXT4_I(inode)->xattr_sem);
+       brelse(iloc.bh);
+       return 1;
+
+out_release_folio:
+       up_read(&EXT4_I(inode)->xattr_sem);
+       folio_unlock(folio);
+       folio_put(folio);
+out_stop_journal:
+       ext4_journal_stop(handle);
+out_release_bh:
+       brelse(iloc.bh);
+       return ret;
+}
+
 /*
  * Try to write data in the inode.
  * If the inode has inline data, check whether the new write can be