From: Zhang Yi <yi.zhang@xxxxxxxxxx> In environments with a page size of 64KB, the maximum size of a folio can reach up to 128MB. Consequently, during the write-back of folios, the 'rsv_blocks' will be overestimated to 1,577, which can make pressure on the journal space where the journal is small. This can easily exceed the limit of a single transaction. Besides, an excessively large folio is meaningless and will instead increase the overhead of traversing the bhs within the folio. Therefore, limit the maximum order of a folio to 2048 filesystem blocks. Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Reported-by: Joseph Qi <jiangqi903@xxxxxxxxx> Closes: https://lore.kernel.org/linux-ext4/CA+G9fYsyYQ3ZL4xaSg1-Tt5Evto7Zd+hgNWZEa9cQLbahA1+xg@xxxxxxxxxxxxxx/ Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx> --- fs/ext4/ext4.h | 2 +- fs/ext4/ialloc.c | 3 +-- fs/ext4/inode.c | 22 +++++++++++++++++++--- 3 files changed, 21 insertions(+), 6 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index f705046ba6c6..9ac0a7d4fa0c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3020,7 +3020,7 @@ int ext4_walk_page_buffers(handle_t *handle, struct buffer_head *bh)); int do_journal_get_write_access(handle_t *handle, struct inode *inode, struct buffer_head *bh); -bool ext4_should_enable_large_folio(struct inode *inode); +void ext4_set_inode_mapping_order(struct inode *inode); #define FALL_BACK_TO_NONDELALLOC 1 #define CONVERT_INLINE_DATA 2 diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 79aa3df8d019..df4051613b29 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -1335,8 +1335,7 @@ struct inode *__ext4_new_inode(struct mnt_idmap *idmap, } } - if (ext4_should_enable_large_folio(inode)) - mapping_set_large_folios(inode->i_mapping); + ext4_set_inode_mapping_order(inode); ext4_update_inode_fsync_trans(handle, inode, 1); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 4b679cb6c8bd..1bce9ebaedb7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5181,7 +5181,7 @@ static int check_igot_inode(struct inode *inode, ext4_iget_flags flags, return -EFSCORRUPTED; } -bool ext4_should_enable_large_folio(struct inode *inode) +static bool ext4_should_enable_large_folio(struct inode *inode) { struct super_block *sb = inode->i_sb; @@ -5198,6 +5198,22 @@ bool ext4_should_enable_large_folio(struct inode *inode) return true; } +/* + * Limit the maximum folio order to 2048 blocks to prevent overestimation + * of reserve handle credits during the folio writeback in environments + * where the PAGE_SIZE exceeds 4KB. + */ +#define EXT4_MAX_PAGECACHE_ORDER(i) \ + min(MAX_PAGECACHE_ORDER, (11 + (i)->i_blkbits - PAGE_SHIFT)) +void ext4_set_inode_mapping_order(struct inode *inode) +{ + if (!ext4_should_enable_large_folio(inode)) + return; + + mapping_set_folio_order_range(inode->i_mapping, 0, + EXT4_MAX_PAGECACHE_ORDER(inode)); +} + struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, ext4_iget_flags flags, const char *function, unsigned int line) @@ -5515,8 +5531,8 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, ret = -EFSCORRUPTED; goto bad_inode; } - if (ext4_should_enable_large_folio(inode)) - mapping_set_large_folios(inode->i_mapping); + + ext4_set_inode_mapping_order(inode); ret = check_igot_inode(inode, flags, function, line); /* -- 2.46.1
