cregit-Linux how code gets into the kernel

Release 4.11 fs/exofs/dir.c

Directory: fs/exofs
/*
 * Copyright (C) 2005, 2006
 * Avishay Traeger (avishay@gmail.com)
 * Copyright (C) 2008, 2009
 * Boaz Harrosh <ooo@electrozaur.com>
 *
 * Copyrights for code taken from ext2:
 *     Copyright (C) 1992, 1993, 1994, 1995
 *     Remy Card (card@masi.ibp.fr)
 *     Laboratoire MASI - Institut Blaise Pascal
 *     Universite Pierre et Marie Curie (Paris VI)
 *     from
 *     linux/fs/minix/inode.c
 *     Copyright (C) 1991, 1992  Linus Torvalds
 *
 * This file is part of exofs.
 *
 * exofs is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.  Since it is based on ext2, and the only
 * valid version of GPL for the Linux kernel is version 2, the only valid
 * version of GPL for exofs is version 2.
 *
 * exofs is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with exofs; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "exofs.h"


static inline unsigned exofs_chunk_size(struct inode *inode) { return inode->i_sb->s_blocksize; }

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Boaz Harrosh19100.00%1100.00%
Total19100.00%1100.00%


static inline void exofs_put_page(struct page *page) { kunmap(page); put_page(page); }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh2195.45%150.00%
Kirill A. Shutemov14.55%150.00%
Total22100.00%2100.00%


static unsigned exofs_last_byte(struct inode *inode, unsigned long page_nr) { loff_t last_byte = inode->i_size; last_byte -= page_nr << PAGE_SHIFT; if (last_byte > PAGE_SIZE) last_byte = PAGE_SIZE; return last_byte; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh3892.68%150.00%
Kirill A. Shutemov37.32%150.00%
Total41100.00%2100.00%


static int exofs_commit_chunk(struct page *page, loff_t pos, unsigned len) { struct address_space *mapping = page->mapping; struct inode *dir = mapping->host; int err = 0; dir->i_version++; if (!PageUptodate(page)) SetPageUptodate(page); if (pos+len > dir->i_size) { i_size_write(dir, pos+len); mark_inode_dirty(dir); } set_page_dirty(page); if (IS_DIRSYNC(dir)) err = write_one_page(page, 1); else unlock_page(page); return err; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh114100.00%1100.00%
Total114100.00%1100.00%


static bool exofs_check_page(struct page *page) { struct inode *dir = page->mapping->host; unsigned chunk_size = exofs_chunk_size(dir); char *kaddr = page_address(page); unsigned offs, rec_len; unsigned limit = PAGE_SIZE; struct exofs_dir_entry *p; char *error; /* if the page is the last one in the directory */ if ((dir->i_size >> PAGE_SHIFT) == page->index) { limit = dir->i_size & ~PAGE_MASK; if (limit & (chunk_size - 1)) goto Ebadsize; if (!limit) goto out; } for (offs = 0; offs <= limit - EXOFS_DIR_REC_LEN(1); offs += rec_len) { p = (struct exofs_dir_entry *)(kaddr + offs); rec_len = le16_to_cpu(p->rec_len); if (rec_len < EXOFS_DIR_REC_LEN(1)) goto Eshort; if (rec_len & 3) goto Ealign; if (rec_len < EXOFS_DIR_REC_LEN(p->name_len)) goto Enamelen; if (((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)) goto Espan; } if (offs != limit) goto Eend; out: SetPageChecked(page); return true; Ebadsize: EXOFS_ERR("ERROR [exofs_check_page]: " "size of directory(0x%lx) is not a multiple of chunk size\n", dir->i_ino ); goto fail; Eshort: error = "rec_len is smaller than minimal"; goto bad_entry; Ealign: error = "unaligned directory entry"; goto bad_entry; Enamelen: error = "rec_len is too small for name_len"; goto bad_entry; Espan: error = "directory entry across blocks"; goto bad_entry; bad_entry: EXOFS_ERR( "ERROR [exofs_check_page]: bad entry in directory(0x%lx): %s - " "offset=%lu, inode=0x%llx, rec_len=%d, name_len=%d\n", dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs, _LLU(le64_to_cpu(p->inode_no)), rec_len, p->name_len); goto fail; Eend: p = (struct exofs_dir_entry *)(kaddr + offs); EXOFS_ERR("ERROR [exofs_check_page]: " "entry in directory(0x%lx) spans the page boundary" "offset=%lu, inode=0x%llx\n", dir->i_ino, (page->index<<PAGE_SHIFT)+offs, _LLU(le64_to_cpu(p->inode_no))); fail: SetPageError(page); return false; }

Contributors

PersonTokensPropCommitsCommitProp
Boaz Harrosh36396.54%240.00%
Al Viro71.86%120.00%
Kirill A. Shutemov51.33%120.00%
Uwe Kleine-König10.27%120.00%
Total376100.00%5100.00%


static struct page *exofs_get_page(struct inode *dir, unsigned long n) { struct address_space *mapping = dir->i_mapping; struct page *page = read_mapping_page(mapping, n, NULL); if (!IS_ERR(page)) { kmap(page); if (unlikely(!PageChecked(page))) { if (PageError(page) || !exofs_check_page(page)) goto fail; } } return page; fail: exofs_put_page(page); return ERR_PTR(-EIO); }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh9089.11%150.00%
Al Viro1110.89%150.00%
Total101100.00%2100.00%


static inline int exofs_match(int len, const unsigned char *name, struct exofs_dir_entry *de) { if (len != de->name_len) return 0; if (!de->inode_no) return 0; return !memcmp(name, de->name, len); }

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Boaz Harrosh55100.00%1100.00%
Total55100.00%1100.00%


static inline struct exofs_dir_entry *exofs_next_entry(struct exofs_dir_entry *p) { return (struct exofs_dir_entry *)((char *)p + le16_to_cpu(p->rec_len)); }

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Boaz Harrosh35100.00%1100.00%
Total35100.00%1100.00%


static inline unsigned exofs_validate_entry(char *base, unsigned offset, unsigned mask) { struct exofs_dir_entry *de = (struct exofs_dir_entry *)(base + offset); struct exofs_dir_entry *p = (struct exofs_dir_entry *)(base + (offset&mask)); while ((char *)p < (char *)de) { if (p->rec_len == 0) break; p = exofs_next_entry(p); } return (char *)p - base; }

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Boaz Harrosh94100.00%1100.00%
Total94100.00%1100.00%

static unsigned char exofs_filetype_table[EXOFS_FT_MAX] = { [EXOFS_FT_UNKNOWN] = DT_UNKNOWN, [EXOFS_FT_REG_FILE] = DT_REG, [EXOFS_FT_DIR] = DT_DIR, [EXOFS_FT_CHRDEV] = DT_CHR, [EXOFS_FT_BLKDEV] = DT_BLK, [EXOFS_FT_FIFO] = DT_FIFO, [EXOFS_FT_SOCK] = DT_SOCK, [EXOFS_FT_SYMLINK] = DT_LNK, }; #define S_SHIFT 12 static unsigned char exofs_type_by_mode[S_IFMT >> S_SHIFT] = { [S_IFREG >> S_SHIFT] = EXOFS_FT_REG_FILE, [S_IFDIR >> S_SHIFT] = EXOFS_FT_DIR, [S_IFCHR >> S_SHIFT] = EXOFS_FT_CHRDEV, [S_IFBLK >> S_SHIFT] = EXOFS_FT_BLKDEV, [S_IFIFO >> S_SHIFT] = EXOFS_FT_FIFO, [S_IFSOCK >> S_SHIFT] = EXOFS_FT_SOCK, [S_IFLNK >> S_SHIFT] = EXOFS_FT_SYMLINK, };
static inline void exofs_set_de_type(struct exofs_dir_entry *de, struct inode *inode) { umode_t mode = inode->i_mode; de->file_type = exofs_type_by_mode[(mode & S_IFMT) >> S_SHIFT]; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh3897.44%150.00%
Al Viro12.56%150.00%
Total39100.00%2100.00%


static int exofs_readdir(struct file *file, struct dir_context *ctx) { loff_t pos = ctx->pos; struct inode *inode = file_inode(file); unsigned int offset = pos & ~PAGE_MASK; unsigned long n = pos >> PAGE_SHIFT; unsigned long npages = dir_pages(inode); unsigned chunk_mask = ~(exofs_chunk_size(inode)-1); int need_revalidate = (file->f_version != inode->i_version); if (pos > inode->i_size - EXOFS_DIR_REC_LEN(1)) return 0; for ( ; n < npages; n++, offset = 0) { char *kaddr, *limit; struct exofs_dir_entry *de; struct page *page = exofs_get_page(inode, n); if (IS_ERR(page)) { EXOFS_ERR("ERROR: bad page in directory(0x%lx)\n", inode->i_ino); ctx->pos += PAGE_SIZE - offset; return PTR_ERR(page); } kaddr = page_address(page); if (unlikely(need_revalidate)) { if (offset) { offset = exofs_validate_entry(kaddr, offset, chunk_mask); ctx->pos = (n<<PAGE_SHIFT) + offset; } file->f_version = inode->i_version; need_revalidate = 0; } de = (struct exofs_dir_entry *)(kaddr + offset); limit = kaddr + exofs_last_byte(inode, n) - EXOFS_DIR_REC_LEN(1); for (; (char *)de <= limit; de = exofs_next_entry(de)) { if (de->rec_len == 0) { EXOFS_ERR("ERROR: " "zero-length entry in directory(0x%lx)\n", inode->i_ino); exofs_put_page(page); return -EIO; } if (de->inode_no) { unsigned char t; if (de->file_type < EXOFS_FT_MAX) t = exofs_filetype_table[de->file_type]; else t = DT_UNKNOWN; if (!dir_emit(ctx, de->name, de->name_len, le64_to_cpu(de->inode_no), t)) { exofs_put_page(page); return 0; } } ctx->pos += le16_to_cpu(de->rec_len); } exofs_put_page(page); } return 0; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh36291.41%240.00%
Al Viro307.58%240.00%
Kirill A. Shutemov41.01%120.00%
Total396100.00%5100.00%


struct exofs_dir_entry *exofs_find_entry(struct inode *dir, struct dentry *dentry, struct page **res_page) { const unsigned char *name = dentry->d_name.name; int namelen = dentry->d_name.len; unsigned reclen = EXOFS_DIR_REC_LEN(namelen); unsigned long start, n; unsigned long npages = dir_pages(dir); struct page *page = NULL; struct exofs_i_info *oi = exofs_i(dir); struct exofs_dir_entry *de; if (npages == 0) goto out; *res_page = NULL; start = oi->i_dir_start_lookup; if (start >= npages) start = 0; n = start; do { char *kaddr; page = exofs_get_page(dir, n); if (!IS_ERR(page)) { kaddr = page_address(page); de = (struct exofs_dir_entry *) kaddr; kaddr += exofs_last_byte(dir, n) - reclen; while ((char *) de <= kaddr) { if (de->rec_len == 0) { EXOFS_ERR("ERROR: zero-length entry in " "directory(0x%lx)\n", dir->i_ino); exofs_put_page(page); goto out; } if (exofs_match(namelen, name, de)) goto found; de = exofs_next_entry(de); } exofs_put_page(page); } if (++n >= npages) n = 0; } while (n != start); out: return NULL; found: *res_page = page; oi->i_dir_start_lookup = n; return de; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh281100.00%2100.00%
Total281100.00%2100.00%


struct exofs_dir_entry *exofs_dotdot(struct inode *dir, struct page **p) { struct page *page = exofs_get_page(dir, 0); struct exofs_dir_entry *de = NULL; if (!IS_ERR(page)) { de = exofs_next_entry( (struct exofs_dir_entry *)page_address(page)); *p = page; } return de; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh70100.00%1100.00%
Total70100.00%1100.00%


ino_t exofs_parent_ino(struct dentry *child) { struct page *page; struct exofs_dir_entry *de; ino_t ino; de = exofs_dotdot(d_inode(child), &page); if (!de) return 0; ino = le64_to_cpu(de->inode_no); exofs_put_page(page); return ino; }

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Boaz Harrosh5895.08%150.00%
David Howells34.92%150.00%
Total61100.00%2100.00%


ino_t exofs_inode_by_name(struct inode *dir, struct dentry *dentry) { ino_t res = 0; struct exofs_dir_entry *de; struct page *page; de = exofs_find_entry(dir, dentry, &page); if (de) { res = le64_to_cpu(de->inode_no); exofs_put_page(page); } return res; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh65100.00%1100.00%
Total65100.00%1100.00%


int exofs_set_link(struct inode *dir, struct exofs_dir_entry *de, struct page *page, struct inode *inode) { loff_t pos = page_offset(page) + (char *) de - (char *) page_address(page); unsigned len = le16_to_cpu(de->rec_len); int err; lock_page(page); err = exofs_write_begin(NULL, page->mapping, pos, len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL); if (err) EXOFS_ERR("exofs_set_link: exofs_write_begin FAILED => %d\n", err); de->inode_no = cpu_to_le64(inode->i_ino); exofs_set_de_type(de, inode); if (likely(!err)) err = exofs_commit_chunk(page, pos, len); exofs_put_page(page); dir->i_mtime = dir->i_ctime = current_time(dir); mark_inode_dirty(dir); return err; }

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PersonTokensPropCommitsCommitProp
Boaz Harrosh15796.91%133.33%
Deepa Dinamani42.47%133.33%
Joe Perches10.62%133.33%
Total162100.00%3100.00%


int exofs_add_link(struct dentry *dentry, struct inode *inode) { struct inode *dir = d_inode(dentry->d_parent); const unsigned char *name = dentry->d_name.name; int namelen = dentry->d_name.len; unsigned chunk_size = exofs_chunk_size(dir); unsigned reclen = EXOFS_DIR_REC_LEN(namelen); unsigned short rec_len, name_len; struct page *page = NULL; struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; struct exofs_dir_entry *de; unsigned long npages = dir_pages(dir); unsigned long n; char *kaddr; loff_t pos; int err; for (n = 0; n <= npages; n++) { char *dir_end; page = exofs_get_page(dir, n); err = PTR_ERR(page); if (IS_ERR(page)) goto out; lock_page(page); kaddr = page_address(page); dir_end = kaddr + exofs_last_byte(dir, n); de = (struct exofs_dir_entry *)kaddr; kaddr += PAGE_SIZE - reclen; while ((char *)de <= kaddr) { if ((char *)de == dir_end) { name_len = 0; rec_len = chunk_size; de->rec_len = cpu_to_le16(chunk_size); de->inode_no = 0; goto got_it; } if (de->rec_len == 0) { EXOFS_ERR("ERROR: exofs_add_link: " "zero-length entry in directory(0x%lx)\n", inode->i_ino); err = -EIO; goto out_unlock; } err = -EEXIST; if (exofs_match(namelen, name, de)) goto out_unlock; name_len = EXOFS_DIR_REC_LEN(de->name_len); rec_len = le16_to_cpu(de->rec_len); if (!de->inode_no && rec_len >= reclen) goto got_it; if (rec_len >= name_len + reclen) goto got_it; de = (struct exofs_dir_entry *) ((char *) de + rec_len); } unlock_page(page); exofs_put_page(page); } EXOFS_ERR("exofs_add_link: BAD dentry=%p or inode=0x%lx\n", dentry, inode->i_ino); return -EINVAL; got_it: pos = page_offset(page) + (char *)de - (char *)page_address(page); err = exofs_write_begin(NULL, page->mapping, pos, rec_len, 0, &page, NULL); if (err) goto out_unlock; if (de->inode_no) { struct exofs_dir_entry *de1 = (struct exofs_dir_entry *)((char *)de + name_len); de1->rec_len = cpu_to_le16(rec_len - name_len); de->rec_len = cpu_to_le16(name_len); de = de1; } de->name_len = namelen; memcpy(de->name, name, namelen); de->inode_no = cpu_to_le64(inode->i_ino); exofs_set_de_type(de, inode); err = exofs_commit_chunk(page, pos, rec_len); dir->i_mtime = dir->i_ctime = current_time(dir); mark_inode_dirty(dir); sbi->s_numfiles++; out_put: exofs_put_page(page); out: return err; out_unlock: unlock_page(page); goto out_put; }

Contributors

PersonTokensPropCommitsCommitProp
Boaz Harrosh56998.61%240.00%
Deepa Dinamani40.69%120.00%
David Howells30.52%120.00%
Kirill A. Shutemov10.17%120.00%
Total577100.00%5100.00%


int exofs_delete_entry(struct exofs_dir_entry *dir, struct page *page) { struct address_space *mapping = page->mapping; struct inode *inode = mapping->host; struct exofs_sb_info *sbi = inode->i_sb->s_fs_info; char *kaddr = page_address(page); unsigned from = ((char *)dir - kaddr) & ~(exofs_chunk_size(inode)-1); unsigned to = ((char *)dir - kaddr) + le16_to_cpu(dir->rec_len); loff_t pos; struct exofs_dir_entry *pde = NULL; struct exofs_dir_entry *de = (struct exofs_dir_entry *) (kaddr + from); int err; while (de < dir) { if (de->rec_len == 0) { EXOFS_ERR("ERROR: exofs_delete_entry:" "zero-length entry in directory(0x%lx)\n", inode->i_ino); err = -EIO; goto out; } pde = de; de = exofs_next_entry(de); } if (pde) from = (char *)pde - (char *)page_address(page); pos = page_offset(page) + from; lock_page(page); err = exofs_write_begin(NULL, page->mapping, pos, to - from, 0, &page, NULL); if (err) EXOFS_ERR("exofs_delete_entry: exofs_write_begin FAILED => %d\n", err); if (pde) pde->rec_len = cpu_to_le16(to - from); dir->inode_no = 0; if (likely(!err)) err = exofs_commit_chunk(page, pos, to - from); inode->i_ctime = inode->i_mtime = current_time(inode); mark_inode_dirty(inode); sbi->s_numfiles--; out: exofs_put_page(page); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Boaz Harrosh31298.42%250.00%
Deepa Dinamani41.26%125.00%
Joe Perches10.32%125.00%
Total317100.00%4100.00%

/* kept aligned on 4 bytes */ #define THIS_DIR ".\0\0" #define PARENT_DIR "..\0"
int exofs_make_empty(struct inode *inode, struct inode *parent) { struct address_space *mapping = inode->i_mapping; struct page *page = grab_cache_page(mapping, 0); unsigned chunk_size = exofs_chunk_size(inode); struct exofs_dir_entry *de; int err; void *kaddr; if (!page) return -ENOMEM; err = exofs_write_begin(NULL, page->mapping, 0, chunk_size, 0, &page, NULL); if (err) { unlock_page(page); goto fail; } kaddr = kmap_atomic(page); de = (struct exofs_dir_entry *)kaddr; de->name_len = 1; de->rec_len = cpu_to_le16(EXOFS_DIR_REC_LEN(1