From 30460e1ea3e62f8457e087db9a309ed1031630da Mon Sep 17 00:00:00 2001 From: Carlos Maiolino Date: Thu, 9 Jan 2020 14:30:41 +0100 Subject: fs: Enable bmap() function to properly return errors By now, bmap() will either return the physical block number related to the requested file offset or 0 in case of error or the requested offset maps into a hole. This patch makes the needed changes to enable bmap() to proper return errors, using the return value as an error return, and now, a pointer must be passed to bmap() to be filled with the mapped physical block. It will change the behavior of bmap() on return: - negative value in case of error - zero on success or map fell into a hole In case of a hole, the *block will be zero too Since this is a prep patch, by now, the only error return is -EINVAL if ->bmap doesn't exist. Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino Signed-off-by: Al Viro --- fs/f2fs/data.c | 16 +++++++++++----- fs/inode.c | 32 +++++++++++++++++++------------- fs/jbd2/journal.c | 22 +++++++++++++++------- 3 files changed, 45 insertions(+), 25 deletions(-) (limited to 'fs') diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a034cd0ce021..e948902c4ec5 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -3170,12 +3170,16 @@ static int check_swap_activate(struct file *swap_file, unsigned int max) while ((probe_block + blocks_per_page) <= last_block && page_no < max) { unsigned block_in_page; sector_t first_block; + sector_t block = 0; + int err = 0; cond_resched(); - first_block = bmap(inode, probe_block); - if (first_block == 0) + block = probe_block; + err = bmap(inode, &block); + if (err || !block) goto bad_bmap; + first_block = block; /* * It must be PAGE_SIZE aligned on-disk @@ -3187,11 +3191,13 @@ static int check_swap_activate(struct file *swap_file, unsigned int max) for (block_in_page = 1; block_in_page < blocks_per_page; block_in_page++) { - sector_t block; - block = bmap(inode, probe_block + block_in_page); - if (block == 0) + block = probe_block + block_in_page; + err = bmap(inode, &block); + + if (err || !block) goto bad_bmap; + if (block != first_block + block_in_page) { /* Discontiguity */ probe_block++; diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694e..5dacfa1fb129 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1598,25 +1598,31 @@ retry: } EXPORT_SYMBOL(iput); +#ifdef CONFIG_BLOCK /** * bmap - find a block number in a file - * @inode: inode of file - * @block: block to find - * - * Returns the block number on the device holding the inode that - * is the disk block number for the block of the file requested. - * That is, asked for block 4 of inode 1 the function will return the - * disk block relative to the disk start that holds that block of the - * file. + * @inode: inode owning the block number being requested + * @block: pointer containing the block to find + * + * Replaces the value in *block with the block number on the device holding + * corresponding to the requested block number in the file. + * That is, asked for block 4 of inode 1 the function will replace the + * 4 in *block, with disk block relative to the disk start that holds that + * block of the file. + * + * Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a + * hole, returns 0 and *block is also set to 0. */ -sector_t bmap(struct inode *inode, sector_t block) +int bmap(struct inode *inode, sector_t *block) { - sector_t res = 0; - if (inode->i_mapping->a_ops->bmap) - res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block); - return res; + if (!inode->i_mapping->a_ops->bmap) + return -EINVAL; + + *block = inode->i_mapping->a_ops->bmap(inode->i_mapping, *block); + return 0; } EXPORT_SYMBOL(bmap); +#endif /* * With relative atime, only update atime if the previous atime is diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 5e408ee24a1a..01fa5d247e39 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -795,18 +795,23 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, { int err = 0; unsigned long long ret; + sector_t block = 0; if (journal->j_inode) { - ret = bmap(journal->j_inode, blocknr); - if (ret) - *retp = ret; - else { + block = blocknr; + ret = bmap(journal->j_inode, &block); + + if (ret || !block) { printk(KERN_ALERT "%s: journal block not found " "at offset %lu on %s\n", __func__, blocknr, journal->j_devname); err = -EIO; __journal_abort_soft(journal, err); + + } else { + *retp = block; } + } else { *retp = blocknr; /* +journal->j_blk_offset */ } @@ -1244,11 +1249,14 @@ journal_t *jbd2_journal_init_dev(struct block_device *bdev, journal_t *jbd2_journal_init_inode(struct inode *inode) { journal_t *journal; + sector_t blocknr; char *p; - unsigned long long blocknr; + int err = 0; + + blocknr = 0; + err = bmap(inode, &blocknr); - blocknr = bmap(inode, 0); - if (!blocknr) { + if (err || !blocknr) { pr_err("%s: Cannot locate journal superblock\n", __func__); return NULL; -- cgit v1.2.3