From 35dd055b94eb3ed8c21595eedd740431866b2f26 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=81ukasz=20Majewski?= Date: Tue, 6 May 2014 09:36:04 +0200 Subject: fs:ext4:cleanup: Remove superfluous code Code responsible for handling situation when ext4 has block size of 1024B can be ordered to take less space. This patch does that for ext4 common and write files. Signed-off-by: Lukasz Majewski --- fs/ext4/ext4_common.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/ext4/ext4_common.c') diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 02da75c0840..62e2e804928 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -904,10 +904,8 @@ long int ext4fs_get_new_blk_no(void) restart: fs->curr_blkno++; /* get the blockbitmap index respective to blockno */ - if (fs->blksz != 1024) { - bg_idx = fs->curr_blkno / blk_per_grp; - } else { - bg_idx = fs->curr_blkno / blk_per_grp; + bg_idx = fs->curr_blkno / blk_per_grp; + if (fs->blksz == 1024) { remainder = fs->curr_blkno % blk_per_grp; if (!remainder) bg_idx--; -- cgit v1.2.3 From 8b454eeeea0ba021ee27f3e103daf1f8fa87bd16 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=81ukasz=20Majewski?= Date: Tue, 6 May 2014 09:36:05 +0200 Subject: fs:ext4:write:fix: Reinitialize global variables after updating a file This bug shows up when file stored on the ext4 file system is updated. The ext4fs_delete_file() is responsible for deleting file's (e.g. uImage) data. However some global data (especially ext4fs_indir2_block), which is used during file deletion are left unchanged. The ext4fs_indir2_block pointer stores reference to old ext4 double indirect allocated blocks. When it is unchanged, after file deletion, ext4fs_write_file() uses the same pointer (since it is already initialized - i.e. not NULL) to return number of blocks to write. This trunks larger file when previous one was smaller. Lets consider following scenario: 1. Flash target with ext4 formatted boot.img (which has uImage [*] on itself) 2. Developer wants to upload their custom uImage [**] - When new uImage [**] is smaller than the [*] - everything works correctly - we are able to store the whole smaller file with corrupted ext4fs_indir2_block pointer - When new uImage [**] is larger than the [*] - theCRC is corrupted, since truncation on data stored at eMMC was done. 3. When uImage CRC error appears, then reboot and LTHOR/DFU reflashing causes proper setting of ext4fs_indir2_block() and after that uImage[**] is successfully stored (correct uImage [*] metadata is stored at an eMMC on the first flashing). Due to above the bug was very difficult to reproduce. This patch sets default values for all ext4fs_indir* pointers/variables. Signed-off-by: Lukasz Majewski --- fs/ext4/ext4_common.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) (limited to 'fs/ext4/ext4_common.c') diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 62e2e804928..1c1172163c0 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -1841,16 +1841,20 @@ long int read_allocated_block(struct ext2_inode *inode, int fileblock) return blknr; } -void ext4fs_close(void) +/** + * ext4fs_reinit_global() - Reinitialize values of ext4 write implementation's + * global pointers + * + * This function assures that for a file with the same name but different size + * the sequential store on the ext4 filesystem will be correct. + * + * In this function the global data, responsible for internal representation + * of the ext4 data are initialized to the reset state. Without this, during + * replacement of the smaller file with the bigger truncation of new file was + * performed. + */ +void ext4fs_reinit_global(void) { - if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) { - ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen); - ext4fs_file = NULL; - } - if (ext4fs_root != NULL) { - free(ext4fs_root); - ext4fs_root = NULL; - } if (ext4fs_indir1_block != NULL) { free(ext4fs_indir1_block); ext4fs_indir1_block = NULL; @@ -1870,6 +1874,19 @@ void ext4fs_close(void) ext4fs_indir3_blkno = -1; } } +void ext4fs_close(void) +{ + if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) { + ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen); + ext4fs_file = NULL; + } + if (ext4fs_root != NULL) { + free(ext4fs_root); + ext4fs_root = NULL; + } + + ext4fs_reinit_global(); +} int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name, struct ext2fs_node **fnode, int *ftype) -- cgit v1.2.3