/* * linux/fs/block_dev.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE */ #include <linux/init.h>#include <linux/mm.h>#include <linux/fcntl.h>#include <linux/slab.h>#include <linux/kmod.h>#include <linux/major.h>#include <linux/smp_lock.h>#include <linux/highmem.h>#include <linux/blkdev.h>#include <linux/module.h>#include <linux/blkpg.h>#include <linux/buffer_head.h>#include <linux/writeback.h>#include <linux/mpage.h>#include <linux/mount.h>#include <linux/uio.h>#include <linux/namei.h>#include <linux/log2.h>#include <asm/uaccess.h>#include "internal.h" struct bdev_inode { struct block_device bdev; struct inode vfs_inode;}; static inline struct bdev_inode *BDEV_I(struct inode *inode){ return container_of(inode, struct bdev_inode, vfs_inode);} inline struct block_device *I_BDEV(struct inode *inode){ return &BDEV_I(inode)->bdev;} EXPORT_SYMBOL(I_BDEV); static sector_t max_block(struct block_device *bdev){ sector_t retval = ~((sector_t)0); loff_t sz = i_size_read(bdev->bd_inode); if (sz) { unsigned int size = block_size(bdev); unsigned int sizebits = blksize_bits(size); retval = (sz >> sizebits); } return retval;} /* Kill _all_ buffers and pagecache , dirty or not.. */static void kill_bdev(struct block_device *bdev){ if (bdev->bd_inode->i_mapping->nrpages == 0) return; invalidate_bh_lrus(); truncate_inode_pages(bdev->bd_inode->i_mapping, 0);} int set_blocksize(struct block_device *bdev, int size){ /* Size must be a power of two, and between 512 and PAGE_SIZE */ if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) return -EINVAL; /* Size cannot be smaller than the size supported by the device */ if (size < bdev_hardsect_size(bdev)) return -EINVAL; /* Don't change the size if it is same as current */ if (bdev->bd_block_size != size) { sync_blockdev(bdev); bdev->bd_block_size = size; bdev->bd_inode->i_blkbits = blksize_bits(size); kill_bdev(bdev); } return 0;} EXPORT_SYMBOL(set_blocksize); int sb_set_blocksize(struct super_block *sb, int size){ if (set_blocksize(sb->s_bdev, size)) return 0; /* If we get here, we know size is power of two * and it's value is between 512 and PAGE_SIZE */ sb->s_blocksize = size; sb->s_blocksize_bits = blksize_bits(size); return sb->s_blocksize;} EXPORT_SYMBOL(sb_set_blocksize); int sb_min_blocksize(struct super_block *sb, int size){ int minsize = bdev_hardsect_size(sb->s_bdev); if (size < minsize) size = minsize; return sb_set_blocksize(sb, size);} EXPORT_SYMBOL(sb_min_blocksize); static intblkdev_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create){ if (iblock >= max_block(I_BDEV(inode))) { if (create) return -EIO; /* * for reads, we're just trying to fill a partial page. * return a hole, they will have to call get_block again * before they can fill it, and they will get -EIO at that * time */ return 0; } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; set_buffer_mapped(bh); return 0;} static intblkdev_get_blocks(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create){ sector_t end_block = max_block(I_BDEV(inode)); unsigned long max_blocks = bh->b_size >> inode->i_blkbits; if ((iblock + max_blocks) > end_block) { max_blocks = end_block - iblock; if ((long)max_blocks <= 0) { if (create) return -EIO; /* write fully beyond EOF */ /* * It is a read which is fully beyond EOF. We return * a !buffer_mapped buffer */ max_blocks = 0; } } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; bh->b_size = max_blocks << inode->i_blkbits; if (max_blocks) set_buffer_mapped(bh); return 0;} static ssize_tblkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs){ struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode), iov, offset, nr_segs, blkdev_get_blocks, NULL);} #if 0static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error){ struct kiocb *iocb = bio->bi_private; atomic_t *bio_count = &iocb->ki_bio_count; if (bio_data_dir(bio) == READ) bio_check_pages_dirty(bio); else { bio_release_pages(bio); bio_put(bio); } /* iocb->ki_nbytes stores error code from LLDD */ if (error) iocb->ki_nbytes = -EIO; if (atomic_dec_and_test(bio_count)) { if ((long)iocb->ki_nbytes < 0) aio_complete(iocb, iocb->ki_nbytes, 0); else aio_complete(iocb, iocb->ki_left, 0); } return 0;} #define VEC_SIZE 16struct pvec { unsigned short nr; unsigned short idx; struct page *page[VEC_SIZE];}; #define PAGES_SPANNED(addr, len) \ (DIV_ROUND_UP((addr) + (len), PAGE_SIZE) - (addr) / PAGE_SIZE); /* * get page pointer for user addr, we internally cache struct page array for * (addr, count) range in pvec to avoid frequent call to get_user_pages. If * internal page list is exhausted, a batch count of up to VEC_SIZE is used * to get next set of page struct. */static struct page *blk_get_page(unsigned long addr, size_t count, int rw, struct pvec *pvec){ int ret, nr_pages; if (pvec->idx == pvec->nr) { nr_pages = PAGES_SPANNED(addr, count); nr_pages = min(nr_pages, VEC_SIZE); down_read(¤t->mm->mmap_sem); ret = get_user_pages(current, current->mm, addr, nr_pages, rw == READ, 0, pvec->page, NULL); up_read(¤t->mm->mmap_sem); if (ret < 0) return ERR_PTR(ret); pvec->nr = ret; pvec->idx = 0; } return pvec->page[pvec->idx++];} /* return a page back to pvec array */static void blk_unget_page(struct page *page, struct pvec *pvec){ pvec->page[--pvec->idx] = page;} static ssize_tblkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs){ struct inode *inode = iocb->ki_filp->f_mapping->host; unsigned blkbits = blksize_bits(bdev_hardsect_size(I_BDEV(inode))); unsigned blocksize_mask = (1 << blkbits) - 1; unsigned long seg = 0; /* iov segment iterator */ unsigned long nvec; /* number of bio vec needed */ unsigned long cur_off; /* offset into current page */ unsigned long cur_len; /* I/O len of current page, up to PAGE_SIZE */ unsigned long addr; /* user iovec address */ size_t count; /* user iovec len */ size_t nbytes = iocb->ki_nbytes = iocb->ki_left; /* total xfer size */ loff_t size; /* size of block device */ struct bio *bio; atomic_t *bio_count = &iocb->ki_bio_count; struct page *page; struct pvec pvec; pvec.nr = 0; pvec.idx = 0; if (pos & blocksize_mask) return -EINVAL; size = i_size_read(inode); if (pos + nbytes > size) { nbytes = size - pos; iocb->ki_left = nbytes; } /* * check first non-zero iov alignment, the remaining * iov alignment is checked inside bio loop below. */ do { addr = (unsigned long) iov[seg].iov_base; count = min(iov[seg].iov_len, nbytes); if (addr & blocksize_mask || count & blocksize_mask) return -EINVAL; } while (!count && ++seg < nr_segs); atomic_set(bio_count, 1); while (nbytes) { /* roughly estimate number of bio vec needed */ nvec = (nbytes + PAGE_SIZE - 1) / PAGE_SIZE; nvec = max(nvec, nr_segs - seg); nvec = min(nvec, (unsigned long) BIO_MAX_PAGES); /* bio_alloc should not fail with GFP_KERNEL flag */ bio = bio_alloc(GFP_KERNEL, nvec); bio->bi_bdev = I_BDEV(inode); bio->bi_end_io = blk_end_aio; bio->bi_private = iocb; bio->bi_sector = pos >> blkbits;same_bio: cur_off = addr & ~PAGE_MASK; cur_len = PAGE_SIZE - cur_off; if (count < cur_len) cur_len = count; page = blk_get_page(addr, count, rw, &pvec); if (unlikely(IS_ERR(page))) goto backout; if (bio_add_page(bio, page, cur_len, cur_off)) { pos += cur_len; addr += cur_len; count -= cur_len; nbytes -= cur_len; if (count) goto same_bio; while (++seg < nr_segs) { addr = (unsigned long) iov[seg].iov_base; count = iov[seg].iov_len; if (!count) continue; if (unlikely(addr & blocksize_mask || count & blocksize_mask)) { page = ERR_PTR(-EINVAL); goto backout; } count = min(count, nbytes); goto same_bio; } } else { blk_unget_page(page, &pvec); } /* bio is ready, submit it */ if (rw == READ) bio_set_pages_dirty(bio); atomic_inc(bio_count); submit_bio(rw, bio); } completion: iocb->ki_left -= nbytes; nbytes = iocb->ki_left; iocb->ki_pos += nbytes; blk_run_address_space(inode->i_mapping); if (atomic_dec_and_test(bio_count)) aio_complete(iocb, nbytes, 0); return -EIOCBQUEUED; backout: /* * back out nbytes count constructed so far for this bio, * we will throw away current bio. */ nbytes += bio->bi_size; bio_release_pages(bio); bio_put(bio); /* * if no bio was submmitted, return the error code. * otherwise, proceed with pending I/O completion. */ if (atomic_read(bio_count) == 1) return PTR_ERR(page); goto completion;}#endif static int blkdev_writepage(struct page *page, struct writeback_control *wbc){ return block_write_full_page(page, blkdev_get_block, wbc);} static int blkdev_readpage(struct file * file, struct page * page){ return block_read_full_page(page, blkdev_get_block);} static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to){ return block_prepare_write(page, from, to, blkdev_get_block);} static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to){ return block_commit_write(page, from, to);} /* * private llseek: * for a block special file file->f_path.dentry->d_inode->i_size is zero * so we compute the size by hand (just as in block_read/write above) */static loff_t block_llseek(struct file *file, loff_t offset, int origin){ struct inode *bd_inode = file->f_mapping->host; loff_t size; loff_t retval; mutex_lock(&bd_inode->i_mutex); size = i_size_read(bd_inode); switch (origin) { case 2: offset += size; break; case 1: offset += file->f_pos; } retval = -EINVAL; if (offset >= 0 && offset <= size) { if (offset != file->f_pos) { file->f_pos = offset; } retval = offset; } mutex_unlock(&bd_inode->i_mutex); return retval;} /* * Filp is never NULL; the only case when ->fsync() is called with * NULL first argument is nfsd_sync_dir() and that's not a directory. */ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync){ return sync_blockdev(I_BDEV(filp->f_mapping->host));} /* * pseudo-fs */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);static struct kmem_cache * bdev_cachep __read_mostly; static struct inode *bdev_alloc_inode(struct super_block *sb){ struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode;} static void bdev_destroy_inode(struct inode *inode){ struct bdev_inode *bdi = BDEV_I(inode); bdi->bdev.bd_inode_backing_dev_info = NULL; kmem_cache_free(bdev_cachep, bdi);} static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags){ struct bdev_inode *ei = (struct bdev_inode *) foo; struct block_device *bdev = &ei->bdev; memset(bdev, 0, sizeof(*bdev)); mutex_init(&bdev->bd_mutex); sema_init(&bdev->bd_mount_sem, 1); INIT_LIST_HEAD(&bdev->bd_inodes); INIT_LIST_HEAD(&bdev->bd_list);#ifdef CONFIG_SYSFS INIT_LIST_HEAD(&bdev->bd_holder_list);#endif inode_init_once(&ei->vfs_inode);} static inline void __bd_forget(struct inode *inode){ list_del_init(&inode->i_devices); inode->i_bdev = NULL; inode->i_mapping = &inode->i_data;} static void bdev_clear_inode(struct inode *inode){ struct block_device *bdev = &BDEV_I(inode)->bdev; struct list_head *p; spin_lock(&bdev_lock); while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { __bd_forget(list_entry(p, struct inode, i_devices)); } list_del_init(&bdev->bd_list); spin_unlock(&bdev_lock);} static const struct super_operations bdev_sops = { .statfs = simple_statfs, .alloc_inode = bdev_alloc_inode, .destroy_inode = bdev_destroy_inode, .drop_inode = generic_delete_inode, .clear_inode = bdev_clear_inode,}; static int bd_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt)Lines 1–500 of 1483. 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/* * linux/fs/block_dev.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE */ #include <linux/init.h> #include <linux/mm.h> #include <linux/fcntl.h> #include <linux/slab.h> #include <linux/kmod.h> #include <linux/major.h> #include <linux/smp_lock.h> #include <linux/highmem.h> #include <linux/blkdev.h> #include <linux/module.h> #include <linux/blkpg.h> #include <linux/buffer_head.h> #include <linux/writeback.h> #include <linux/mpage.h> #include <linux/mount.h> #include <linux/uio.h> #include <linux/namei.h> #include <linux/log2.h> #include <asm/uaccess.h> #include "internal.h" struct bdev_inode { struct block_device bdev; struct inode vfs_inode; }; static inline struct bdev_inode *BDEV_I(struct inode *inode) { return container_of(inode, struct bdev_inode, vfs_inode); } inline struct block_device *I_BDEV(struct inode *inode) { return &BDEV_I(inode)->bdev; } EXPORT_SYMBOL(I_BDEV); static sector_t max_block(struct block_device *bdev) { sector_t retval = ~((sector_t)0); loff_t sz = i_size_read(bdev->bd_inode); if (sz) { unsigned int size = block_size(bdev); unsigned int sizebits = blksize_bits(size); retval = (sz >> sizebits); } return retval; } /* Kill _all_ buffers and pagecache , dirty or not.. */ static void kill_bdev(struct block_device *bdev) { if (bdev->bd_inode->i_mapping->nrpages == 0) return; invalidate_bh_lrus(); truncate_inode_pages(bdev->bd_inode->i_mapping, 0); } int set_blocksize(struct block_device *bdev, int size) { /* Size must be a power of two, and between 512 and PAGE_SIZE */ if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) return -EINVAL; /* Size cannot be smaller than the size supported by the device */ if (size < bdev_hardsect_size(bdev)) return -EINVAL; /* Don't change the size if it is same as current */ if (bdev->bd_block_size != size) { sync_blockdev(bdev); bdev->bd_block_size = size; bdev->bd_inode->i_blkbits = blksize_bits(size); kill_bdev(bdev); } return 0; } EXPORT_SYMBOL(set_blocksize); int sb_set_blocksize(struct super_block *sb, int size) { if (set_blocksize(sb->s_bdev, size)) return 0; /* If we get here, we know size is power of two * and it's value is between 512 and PAGE_SIZE */ sb->s_blocksize = size; sb->s_blocksize_bits = blksize_bits(size); return sb->s_blocksize; } EXPORT_SYMBOL(sb_set_blocksize); int sb_min_blocksize(struct super_block *sb, int size) { int minsize = bdev_hardsect_size(sb->s_bdev); if (size < minsize) size = minsize; return sb_set_blocksize(sb, size); } EXPORT_SYMBOL(sb_min_blocksize); static int blkdev_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { if (iblock >= max_block(I_BDEV(inode))) { if (create) return -EIO; /* * for reads, we're just trying to fill a partial page. * return a hole, they will have to call get_block again * before they can fill it, and they will get -EIO at that * time */ return 0; } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; set_buffer_mapped(bh); return 0; } static int blkdev_get_blocks(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { sector_t end_block = max_block(I_BDEV(inode)); unsigned long max_blocks = bh->b_size >> inode->i_blkbits; if ((iblock + max_blocks) > end_block) { max_blocks = end_block - iblock; if ((long)max_blocks <= 0) { if (create) return -EIO; /* write fully beyond EOF */ /* * It is a read which is fully beyond EOF. We return * a !buffer_mapped buffer */ max_blocks = 0; } } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; bh->b_size = max_blocks << inode->i_blkbits; if (max_blocks) set_buffer_mapped(bh); return 0; } static ssize_t blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode), iov, offset, nr_segs, blkdev_get_blocks, NULL); } #if 0 static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error) { struct kiocb *iocb = bio->bi_private; atomic_t *bio_count = &iocb->ki_bio_count; if (bio_data_dir(bio) == READ) bio_check_pages_dirty(bio); else { bio_release_pages(bio); bio_put(bio); } /* iocb->ki_nbytes stores error code from LLDD */ if (error) iocb->ki_nbytes = -EIO; if (atomic_dec_and_test(bio_count)) { if ((long)iocb->ki_nbytes < 0) aio_complete(iocb, iocb->ki_nbytes, 0); else aio_complete(iocb, iocb->ki_left, 0); } return 0; } #define VEC_SIZE 16 struct pvec { unsigned short nr; unsigned short idx; struct page *page[VEC_SIZE]; }; #define PAGES_SPANNED(addr, len) \ (DIV_ROUND_UP((addr) + (len), PAGE_SIZE) - (addr) / PAGE_SIZE); /* * get page pointer for user addr, we internally cache struct page array for * (addr, count) range in pvec to avoid frequent call to get_user_pages. If * internal page list is exhausted, a batch count of up to VEC_SIZE is used * to get next set of page struct. */ static struct page *blk_get_page(unsigned long addr, size_t count, int rw, struct pvec *pvec) { int ret, nr_pages; if (pvec->idx == pvec->nr) { nr_pages = PAGES_SPANNED(addr, count); nr_pages = min(nr_pages, VEC_SIZE); down_read(¤t->mm->mmap_sem); ret = get_user_pages(current, current->mm, addr, nr_pages, rw == READ, 0, pvec->page, NULL); up_read(¤t->mm->mmap_sem); if (ret < 0) return ERR_PTR(ret); pvec->nr = ret; pvec->idx = 0; } return pvec->page[pvec->idx++]; } /* return a page back to pvec array */ static void blk_unget_page(struct page *page, struct pvec *pvec) { pvec->page[--pvec->idx] = page; } static ssize_t blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs) { struct inode *inode = iocb->ki_filp->f_mapping->host; unsigned blkbits = blksize_bits(bdev_hardsect_size(I_BDEV(inode))); unsigned blocksize_mask = (1 << blkbits) - 1; unsigned long seg = 0; /* iov segment iterator */ unsigned long nvec; /* number of bio vec needed */ unsigned long cur_off; /* offset into current page */ unsigned long cur_len; /* I/O len of current page, up to PAGE_SIZE */ unsigned long addr; /* user iovec address */ size_t count; /* user iovec len */ size_t nbytes = iocb->ki_nbytes = iocb->ki_left; /* total xfer size */ loff_t size; /* size of block device */ struct bio *bio; atomic_t *bio_count = &iocb->ki_bio_count; struct page *page; struct pvec pvec; pvec.nr = 0; pvec.idx = 0; if (pos & blocksize_mask) return -EINVAL; size = i_size_read(inode); if (pos + nbytes > size) { nbytes = size - pos; iocb->ki_left = nbytes; } /* * check first non-zero iov alignment, the remaining * iov alignment is checked inside bio loop below. */ do { addr = (unsigned long) iov[seg].iov_base; count = min(iov[seg].iov_len, nbytes); if (addr & blocksize_mask || count & blocksize_mask) return -EINVAL; } while (!count && ++seg < nr_segs); atomic_set(bio_count, 1); while (nbytes) { /* roughly estimate number of bio vec needed */ nvec = (nbytes + PAGE_SIZE - 1) / PAGE_SIZE; nvec = max(nvec, nr_segs - seg); nvec = min(nvec, (unsigned long) BIO_MAX_PAGES); /* bio_alloc should not fail with GFP_KERNEL flag */ bio = bio_alloc(GFP_KERNEL, nvec); bio->bi_bdev = I_BDEV(inode); bio->bi_end_io = blk_end_aio; bio->bi_private = iocb; bio->bi_sector = pos >> blkbits; same_bio: cur_off = addr & ~PAGE_MASK; cur_len = PAGE_SIZE - cur_off; if (count < cur_len) cur_len = count; page = blk_get_page(addr, count, rw, &pvec); if (unlikely(IS_ERR(page))) goto backout; if (bio_add_page(bio, page, cur_len, cur_off)) { pos += cur_len; addr += cur_len; count -= cur_len; nbytes -= cur_len; if (count) goto same_bio; while (++seg < nr_segs) { addr = (unsigned long) iov[seg].iov_base; count = iov[seg].iov_len; if (!count) continue; if (unlikely(addr & blocksize_mask || count & blocksize_mask)) { page = ERR_PTR(-EINVAL); goto backout; } count = min(count, nbytes); goto same_bio; } } else { blk_unget_page(page, &pvec); } /* bio is ready, submit it */ if (rw == READ) bio_set_pages_dirty(bio); atomic_inc(bio_count); submit_bio(rw, bio); } completion: iocb->ki_left -= nbytes; nbytes = iocb->ki_left; iocb->ki_pos += nbytes; blk_run_address_space(inode->i_mapping); if (atomic_dec_and_test(bio_count)) aio_complete(iocb, nbytes, 0); return -EIOCBQUEUED; backout: /* * back out nbytes count constructed so far for this bio, * we will throw away current bio. */ nbytes += bio->bi_size; bio_release_pages(bio); bio_put(bio); /* * if no bio was submmitted, return the error code. * otherwise, proceed with pending I/O completion. */ if (atomic_read(bio_count) == 1) return PTR_ERR(page); goto completion; } #endif static int blkdev_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, blkdev_get_block, wbc); } static int blkdev_readpage(struct file * file, struct page * page) { return block_read_full_page(page, blkdev_get_block); } static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { return block_prepare_write(page, from, to, blkdev_get_block); } static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to) { return block_commit_write(page, from, to); } /* * private llseek: * for a block special file file->f_path.dentry->d_inode->i_size is zero * so we compute the size by hand (just as in block_read/write above) */ static loff_t block_llseek(struct file *file, loff_t offset, int origin) { struct inode *bd_inode = file->f_mapping->host; loff_t size; loff_t retval; mutex_lock(&bd_inode->i_mutex); size = i_size_read(bd_inode); switch (origin) { case 2: offset += size; break; case 1: offset += file->f_pos; } retval = -EINVAL; if (offset >= 0 && offset <= size) { if (offset != file->f_pos) { file->f_pos = offset; } retval = offset; } mutex_unlock(&bd_inode->i_mutex); return retval; } /* * Filp is never NULL; the only case when ->fsync() is called with * NULL first argument is nfsd_sync_dir() and that's not a directory. */ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync) { return sync_blockdev(I_BDEV(filp->f_mapping->host)); } /* * pseudo-fs */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); static struct kmem_cache * bdev_cachep __read_mostly; static struct inode *bdev_alloc_inode(struct super_block *sb) { struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; } static void bdev_destroy_inode(struct inode *inode) { struct bdev_inode *bdi = BDEV_I(inode); bdi->bdev.bd_inode_backing_dev_info = NULL; kmem_cache_free(bdev_cachep, bdi); } static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) { struct bdev_inode *ei = (struct bdev_inode *) foo; struct block_device *bdev = &ei->bdev; memset(bdev, 0, sizeof(*bdev)); mutex_init(&bdev->bd_mutex); sema_init(&bdev->bd_mount_sem, 1); INIT_LIST_HEAD(&bdev->bd_inodes); INIT_LIST_HEAD(&bdev->bd_list); #ifdef CONFIG_SYSFS INIT_LIST_HEAD(&bdev->bd_holder_list); #endif inode_init_once(&ei->vfs_inode); } static inline void __bd_forget(struct inode *inode) { list_del_init(&inode->i_devices); inode->i_bdev = NULL; inode->i_mapping = &inode->i_data; } static void bdev_clear_inode(struct inode *inode) { struct block_device *bdev = &BDEV_I(inode)->bdev; struct list_head *p; spin_lock(&bdev_lock); while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { __bd_forget(list_entry(p, struct inode, i_devices)); } list_del_init(&bdev->bd_list); spin_unlock(&bdev_lock); } static const struct super_operations bdev_sops = { .statfs = simple_statfs, .alloc_inode = bdev_alloc_inode, .destroy_inode = bdev_destroy_inode, .drop_inode = generic_delete_inode, .clear_inode = bdev_clear_inode, }; static int bd_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt)