diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fat/cache.c | 70 | ||||
| -rw-r--r-- | fs/fat/fat.h | 6 | ||||
| -rw-r--r-- | fs/fat/file.c | 78 | ||||
| -rw-r--r-- | fs/fat/inode.c | 87 |
4 files changed, 219 insertions, 22 deletions
diff --git a/fs/fat/cache.c b/fs/fat/cache.c index 91ad9e1c9441..e26bc9a22ac9 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -303,6 +303,31 @@ static int fat_bmap_cluster(struct inode *inode, int cluster) return dclus; } +static int fat_get_mapped_cluster(struct inode *inode, sector_t sector, + sector_t last_block, + unsigned long *mapped_blocks, sector_t *bmap) +{ + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + int cluster, offset; + + cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); + offset = sector & (sbi->sec_per_clus - 1); + cluster = fat_bmap_cluster(inode, cluster); + + if (cluster < 0) + return cluster; + + else if (cluster) { + *bmap = fat_clus_to_blknr(sbi, cluster) + offset; + *mapped_blocks = sbi->sec_per_clus - offset; + if (*mapped_blocks > last_block - sector) + *mapped_blocks = last_block - sector; + } + + return 0; +} + int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, unsigned long *mapped_blocks, int create) { @@ -311,7 +336,6 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, const unsigned long blocksize = sb->s_blocksize; const unsigned char blocksize_bits = sb->s_blocksize_bits; sector_t last_block; - int cluster, offset; *phys = 0; *mapped_blocks = 0; @@ -329,25 +353,39 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, return 0; /* - * ->mmu_private can access on only allocation path. - * (caller must hold ->i_mutex) + * Both ->mmu_private and ->i_disksize can access + * on only allocation path. (caller must hold ->i_mutex) */ - last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1)) + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1)) >> blocksize_bits; if (sector >= last_block) return 0; } - cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); - offset = sector & (sbi->sec_per_clus - 1); - cluster = fat_bmap_cluster(inode, cluster); - if (cluster < 0) - return cluster; - else if (cluster) { - *phys = fat_clus_to_blknr(sbi, cluster) + offset; - *mapped_blocks = sbi->sec_per_clus - offset; - if (*mapped_blocks > last_block - sector) - *mapped_blocks = last_block - sector; - } - return 0; + return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks, + phys); +} + +int fat_bmap2(struct inode *inode, sector_t sector, + unsigned long *mapped_blocks, struct buffer_head *bh_result, + int create, sector_t *bmap) +{ + struct super_block *sb = inode->i_sb; + sector_t last_block; + const unsigned long blocksize = sb->s_blocksize; + const unsigned char blocksize_bits = sb->s_blocksize_bits; + + BUG_ON(create != 0); + + *bmap = 0; + *mapped_blocks = 0; + + last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1)) + >> blocksize_bits; + + if (sector >= last_block) + return 0; + + return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks, + bmap); } diff --git a/fs/fat/fat.h b/fs/fat/fat.h index e0c4ba39a377..13b7202bd651 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -119,7 +119,8 @@ struct msdos_inode_info { unsigned int cache_valid_id; /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ - loff_t mmu_private; /* physically allocated size */ + loff_t mmu_private; /* physically allocated size (initialized) */ + loff_t i_disksize; /* physically allocated size (uninitialized) */ int i_start; /* first cluster or 0 */ int i_logstart; /* logical first cluster */ @@ -290,6 +291,9 @@ extern int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus); extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, unsigned long *mapped_blocks, int create); +extern int fat_bmap2(struct inode *inode, sector_t sector, + unsigned long *mapped_blocks, + struct buffer_head *bh_result, int create, sector_t *bmap); /* fat/dir.c */ extern const struct file_operations fat_dir_operations; diff --git a/fs/fat/file.c b/fs/fat/file.c index 85f79a89e747..92e9e753b554 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -17,8 +17,12 @@ #include <linux/blkdev.h> #include <linux/fsnotify.h> #include <linux/security.h> +#include <linux/falloc.h> #include "fat.h" +static long fat_fallocate(struct file *file, int mode, + loff_t offset, loff_t len); + static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr) { u32 attr; @@ -182,6 +186,7 @@ const struct file_operations fat_file_operations = { #endif .fsync = fat_file_fsync, .splice_read = generic_file_splice_read, + .fallocate = fat_fallocate, }; static int fat_cont_expand(struct inode *inode, loff_t size) @@ -220,6 +225,75 @@ out: return err; } +/* + * Preallocate space for a file. This implements fat's fallocate file + * operation, which gets called from sys_fallocate system call. User + * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set + * we just allocate clusters without zeroing them out. Otherwise we + * allocate and zero out clusters via an expanding truncate. + */ +static long fat_fallocate(struct file *file, int mode, + loff_t offset, loff_t len) +{ + int cluster; + int nr_cluster; /* Number of clusters to be allocated */ + loff_t mm_bytes; /* Number of bytes to be allocated for file */ + struct inode *inode = file->f_mapping->host; + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + int err = 0; + + /* No support for hole punch or other fallocate flags. */ + if (mode & ~FALLOC_FL_KEEP_SIZE) + return -EOPNOTSUPP; + + /* No support for dir */ + if (!S_ISREG(inode->i_mode)) + return -EOPNOTSUPP; + + mutex_lock(&inode->i_mutex); + if ((offset + len) <= MSDOS_I(inode)->i_disksize) + goto error; + + err = inode_newsize_ok(inode, (len + offset)); + if (err) + goto error; + + if (mode & FALLOC_FL_KEEP_SIZE) { + /* First compute the number of clusters to be allocated */ + mm_bytes = offset + len - round_up(MSDOS_I(inode)->i_disksize, + sbi->cluster_size); + nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >> + sbi->cluster_bits; + + /* Start the allocation.We are not zeroing out the clusters */ + while (nr_cluster-- > 0) { + err = fat_alloc_clusters(inode, &cluster, 1); + if (err) { + fat_msg(sb, KERN_ERR, + "fat_fallocate(): fat_alloc_clusters() error"); + goto error; + } + err = fat_chain_add(inode, cluster, 1); + if (err) { + fat_free_clusters(inode, cluster); + goto error; + } + MSDOS_I(inode)->i_disksize += sbi->cluster_size; + } + } else { + /* This is just an expanding truncate */ + err = fat_cont_expand(inode, (offset + len)); + if (err) + fat_msg(sb, KERN_ERR, + "fat_fallocate(): fat_cont_expand() error"); + } + +error: + mutex_unlock(&inode->i_mutex); + return err; +} + /* Free all clusters after the skip'th cluster. */ static int fat_free(struct inode *inode, int skip) { @@ -300,8 +374,10 @@ void fat_truncate_blocks(struct inode *inode, loff_t offset) * This protects against truncating a file bigger than it was then * trying to write into the hole. */ - if (MSDOS_I(inode)->mmu_private > offset) + if (MSDOS_I(inode)->i_disksize > offset) { MSDOS_I(inode)->mmu_private = offset; + MSDOS_I(inode)->i_disksize = offset; + } nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits; diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 756aead10d96..c3b86c58ad88 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -116,6 +116,25 @@ static int fat_add_cluster(struct inode *inode) return err; } +static void check_fallocated_region(struct inode *inode, sector_t iblock, + unsigned long *max_blocks, struct buffer_head *bh_result) +{ + struct super_block *sb = inode->i_sb; + sector_t last_block, disk_block; + const unsigned long blocksize = sb->s_blocksize; + const unsigned char blocksize_bits = sb->s_blocksize_bits; + + last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1)) + >> blocksize_bits; + disk_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1)) + >> blocksize_bits; + if (iblock >= last_block && iblock <= disk_block) { + MSDOS_I(inode)->mmu_private += *max_blocks << blocksize_bits; + set_buffer_new(bh_result); + } + +} + static inline int __fat_get_block(struct inode *inode, sector_t iblock, unsigned long *max_blocks, struct buffer_head *bh_result, int create) @@ -130,8 +149,11 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, if (err) return err; if (phys) { - map_bh(bh_result, sb, phys); *max_blocks = min(mapped_blocks, *max_blocks); + if (create) + check_fallocated_region(inode, iblock, max_blocks, + bh_result); + map_bh(bh_result, sb, phys); return 0; } if (!create) @@ -155,6 +177,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, *max_blocks = min(mapped_blocks, *max_blocks); MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; + MSDOS_I(inode)->i_disksize = MSDOS_I(inode)->mmu_private; err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); if (err) @@ -269,6 +292,13 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, loff_t size = offset + count; if (MSDOS_I(inode)->mmu_private < size) return 0; + + /* + * In case of writing in fallocated region, return 0 and + * fallback to buffered write. + */ + if (MSDOS_I(inode)->i_disksize > MSDOS_I(inode)->mmu_private) + return 0; } /* @@ -282,13 +312,36 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, return ret; } +static int fat_get_block_bmap(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + struct super_block *sb = inode->i_sb; + unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; + int err; + sector_t bmap; + unsigned long mapped_blocks; + + err = fat_bmap2(inode, iblock, &mapped_blocks, bh_result, create, + &bmap); + if (err) + return err; + + if (bmap) { + map_bh(bh_result, sb, bmap); + max_blocks = min(mapped_blocks, max_blocks); + } + + bh_result->b_size = max_blocks << sb->s_blocksize_bits; + return 0; +} + static sector_t _fat_bmap(struct address_space *mapping, sector_t block) { sector_t blocknr; /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ down_read(&MSDOS_I(mapping->host)->truncate_lock); - blocknr = generic_block_bmap(mapping, block, fat_get_block); + blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); up_read(&MSDOS_I(mapping->host)->truncate_lock); return blocknr; @@ -469,7 +522,6 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) error = fat_calc_dir_size(inode); if (error < 0) return error; - MSDOS_I(inode)->mmu_private = inode->i_size; set_nlink(inode, fat_subdirs(inode)); } else { /* not a directory */ @@ -484,8 +536,12 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) inode->i_op = &fat_file_inode_operations; inode->i_fop = &fat_file_operations; inode->i_mapping->a_ops = &fat_aops; - MSDOS_I(inode)->mmu_private = inode->i_size; } + + MSDOS_I(inode)->mmu_private = inode->i_size; + MSDOS_I(inode)->i_disksize = round_up(inode->i_size, + inode->i_sb->s_blocksize); + if (de->attr & ATTR_SYS) { if (sbi->options.sys_immutable) inode->i_flags |= S_IMMUTABLE; @@ -550,12 +606,34 @@ out: EXPORT_SYMBOL_GPL(fat_build_inode); +static int __fat_write_inode(struct inode *inode, int wait); static void fat_evict_inode(struct inode *inode) { truncate_inode_pages_final(&inode->i_data); if (!inode->i_nlink) { inode->i_size = 0; fat_truncate_blocks(inode, 0); + } else { + /* Release unwritten fallocated blocks on inode eviction. */ + if (MSDOS_I(inode)->i_disksize > + round_up(MSDOS_I(inode)->mmu_private, + inode->i_sb->s_blocksize)) { + int err; + fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); + /* Fallocate results in updating the i_start/iogstart + * for the zero byte file. So, make it return to + * original state during evict and commit it to avoid + * any corruption on the next access to the cluster + * chain for the file. + */ + err = __fat_write_inode(inode, inode_needs_sync(inode)); + if (err) { + fat_msg(inode->i_sb, KERN_WARNING, "Failed to " + "update on disk inode for unused fallocated " + "blocks, inode could be corrupted. Please run " + "fsck"); + } + } } invalidate_inode_buffers(inode); clear_inode(inode); @@ -1293,6 +1371,7 @@ static int fat_read_root(struct inode *inode) & ~((loff_t)sbi->cluster_size - 1)) >> 9; MSDOS_I(inode)->i_logstart = 0; MSDOS_I(inode)->mmu_private = inode->i_size; + MSDOS_I(inode)->i_disksize = inode->i_size; fat_save_attrs(inode, ATTR_DIR); inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; |