| Message ID | 20200427181957.1606257-9-hch@lst.de |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [01/11] ext4: fix EXT4_MAX_LOGICAL_BLOCK macro | expand |
On Mon, Apr 27, 2020 at 9:20 PM Christoph Hellwig <hch@lst.de> wrote: > > Replace fiemap_check_flags with a fiemap_validate helpers that also takes Leftover fiemap_validate > the inode and mapped range, and performs the sanity check and truncation > previously done in fiemap_check_range. This way the validation is inside > the file system itself and thus properly works for the stacked overlayfs > case as well. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Thanks for fixing this, Amir.
On Mon, Apr 27, 2020 at 08:19:54PM +0200, Christoph Hellwig wrote: > Replace fiemap_check_flags with a fiemap_validate helpers that also takes "...with a fiemap_prep helper..." ? (new to this patchset, confused) --D > the inode and mapped range, and performs the sanity check and truncation > previously done in fiemap_check_range. This way the validation is inside > the file system itself and thus properly works for the stacked overlayfs > case as well. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > Documentation/filesystems/fiemap.txt | 8 ++--- > fs/btrfs/inode.c | 2 +- > fs/cifs/smb2ops.c | 6 ++-- > fs/ext4/extents.c | 5 +-- > fs/f2fs/data.c | 3 +- > fs/ioctl.c | 53 +++++++++++----------------- > fs/iomap/fiemap.c | 2 +- > fs/nilfs2/inode.c | 2 +- > fs/ocfs2/extent_map.c | 3 +- > include/linux/fiemap.h | 3 +- > 10 files changed, 40 insertions(+), 47 deletions(-) > > diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt > index ac87e6fda842b..05926b7f92809 100644 > --- a/Documentation/filesystems/fiemap.txt > +++ b/Documentation/filesystems/fiemap.txt > @@ -203,15 +203,13 @@ EINTR once fatal signal received. > > > Flag checking should be done at the beginning of the ->fiemap callback via the > -fiemap_check_flags() helper: > - > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); > +fiemap_prep() helper. > > The struct fieinfo should be passed in as received from ioctl_fiemap(). The > set of fiemap flags which the fs understands should be passed via fs_flags. If > -fiemap_check_flags finds invalid user flags, it will place the bad values in > +fiemap_prep finds invalid user flags, it will place the bad values in > fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from > -fiemap_check_flags(), it should immediately exit, returning that error back to > +fiemap_prep(), it should immediately exit, returning that error back to > ioctl_fiemap(). > > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 320d1062068d3..1f1ec361089b3 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -8250,7 +8250,7 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > { > int ret; > > - ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); > + ret = fiemap_prep(inode, fieinfo, start, &len, BTRFS_FIEMAP_FLAGS); > if (ret) > return ret; > > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > index 09047f1ddfb66..8a2e94931dc96 100644 > --- a/fs/cifs/smb2ops.c > +++ b/fs/cifs/smb2ops.c > @@ -3408,8 +3408,10 @@ static int smb3_fiemap(struct cifs_tcon *tcon, > int i, num, rc, flags, last_blob; > u64 next; > > - if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC)) > - return -EBADR; > + rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len, > + FIEMAP_FLAG_SYNC); > + if (rc) > + rc; > > xid = get_xid(); > again: > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index a41ae7c510170..41f73dea92cac 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -4908,8 +4908,9 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, > fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; > } > > - if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)) > - return -EBADR; > + error = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > + if (error) > + return error; > > error = ext4_fiemap_check_ranges(inode, start, &len); > if (error) > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 25abbbb65ba09..03faafc591b17 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1825,7 +1825,8 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > return ret; > } > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); > + ret = fiemap_prep(inode, fieinfo, start, &len, > + FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); > if (ret) > return ret; > > diff --git a/fs/ioctl.c b/fs/ioctl.c > index cbc84e23d00bd..4d94c20c9596b 100644 > --- a/fs/ioctl.c > +++ b/fs/ioctl.c > @@ -141,9 +141,12 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, > EXPORT_SYMBOL(fiemap_fill_next_extent); > > /** > - * fiemap_check_flags - check validity of requested flags for fiemap > + * fiemap_prep - check validity of requested flags for fiemap > + * @inode: Inode to operate on > * @fieinfo: Fiemap context passed into ->fiemap > - * @fs_flags: Set of fiemap flags that the file system understands > + * @start: Start of the mapped range > + * @len: Length of the mapped range, can be truncated by this function. > + * @supported_flags: Set of fiemap flags that the file system understands > * > * Called from file system ->fiemap callback. This will compute the > * intersection of valid fiemap flags and those that the fs supports. That > @@ -154,48 +157,38 @@ EXPORT_SYMBOL(fiemap_fill_next_extent); > * > * Returns 0 on success, -EBADR on bad flags. > */ > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags) > +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, > + u64 start, u64 *len, u32 supported_flags) > { > + u64 maxbytes = inode->i_sb->s_maxbytes; > u32 incompat_flags; > > - incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags); > - if (incompat_flags) { > - fieinfo->fi_flags = incompat_flags; > - return -EBADR; > - } > - return 0; > -} > -EXPORT_SYMBOL(fiemap_check_flags); > - > -static int fiemap_check_ranges(struct super_block *sb, > - u64 start, u64 len, u64 *new_len) > -{ > - u64 maxbytes = (u64) sb->s_maxbytes; > - > - *new_len = len; > - > - if (len == 0) > + if (*len == 0) > return -EINVAL; > - > if (start > maxbytes) > return -EFBIG; > > /* > * Shrink request scope to what the fs can actually handle. > */ > - if (len > maxbytes || (maxbytes - len) < start) > - *new_len = maxbytes - start; > + if (*len > maxbytes || (maxbytes - *len) < start) > + *len = maxbytes - start; > > + supported_flags &= FIEMAP_FLAGS_COMPAT; > + incompat_flags = fieinfo->fi_flags & ~supported_flags; > + if (incompat_flags) { > + fieinfo->fi_flags = incompat_flags; > + return -EBADR; > + } > return 0; > } > +EXPORT_SYMBOL(fiemap_prep); > > static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > { > struct fiemap fiemap; > struct fiemap_extent_info fieinfo = { 0, }; > struct inode *inode = file_inode(filp); > - struct super_block *sb = inode->i_sb; > - u64 len; > int error; > > if (!inode->i_op->fiemap) > @@ -207,11 +200,6 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS) > return -EINVAL; > > - error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length, > - &len); > - if (error) > - return error; > - > fieinfo.fi_flags = fiemap.fm_flags; > fieinfo.fi_extents_max = fiemap.fm_extent_count; > fieinfo.fi_extents_start = ufiemap->fm_extents; > @@ -224,7 +212,8 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC) > filemap_write_and_wait(inode->i_mapping); > > - error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len); > + error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, > + fiemap.fm_length); > fiemap.fm_flags = fieinfo.fi_flags; > fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped; > if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap))) > @@ -312,7 +301,7 @@ static int __generic_block_fiemap(struct inode *inode, > bool past_eof = false, whole_file = false; > int ret = 0; > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c > index dd04e4added15..5e4e3520424da 100644 > --- a/fs/iomap/fiemap.c > +++ b/fs/iomap/fiemap.c > @@ -75,7 +75,7 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, > ctx.fi = fi; > ctx.prev.type = IOMAP_HOLE; > > - ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fi, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c > index 6e1aca38931f3..052c2da11e4d7 100644 > --- a/fs/nilfs2/inode.c > +++ b/fs/nilfs2/inode.c > @@ -1006,7 +1006,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > unsigned int blkbits = inode->i_blkbits; > int ret, n; > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > index e3e2d1b2af51a..3744179b73fa1 100644 > --- a/fs/ocfs2/extent_map.c > +++ b/fs/ocfs2/extent_map.c > @@ -746,7 +746,8 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > struct buffer_head *di_bh = NULL; > struct ocfs2_extent_rec rec; > > - ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS); > + ret = fiemap_prep(inode, fieinfo, map_start, &map_len, > + OCFS2_FIEMAP_FLAGS); > if (ret) > return ret; > > diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h > index 240d4f7d9116a..4e624c4665837 100644 > --- a/include/linux/fiemap.h > +++ b/include/linux/fiemap.h > @@ -13,9 +13,10 @@ struct fiemap_extent_info { > fiemap_extent array */ > }; > > +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, > + u64 start, u64 *len, u32 supported_flags); > int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, > u64 phys, u64 len, u32 flags); > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); > > int generic_block_fiemap(struct inode *inode, > struct fiemap_extent_info *fieinfo, u64 start, u64 len, > -- > 2.26.1 >
On 4/27/20 11:49 PM, Christoph Hellwig wrote: > Replace fiemap_check_flags with a fiemap_validate helpers that also takes > the inode and mapped range, and performs the sanity check and truncation > previously done in fiemap_check_range. This way the validation is inside > the file system itself and thus properly works for the stacked overlayfs > case as well. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > Documentation/filesystems/fiemap.txt | 8 ++--- > fs/btrfs/inode.c | 2 +- > fs/cifs/smb2ops.c | 6 ++-- > fs/ext4/extents.c | 5 +-- > fs/f2fs/data.c | 3 +- > fs/ioctl.c | 53 +++++++++++----------------- > fs/iomap/fiemap.c | 2 +- > fs/nilfs2/inode.c | 2 +- > fs/ocfs2/extent_map.c | 3 +- > include/linux/fiemap.h | 3 +- > 10 files changed, 40 insertions(+), 47 deletions(-) > > diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt > index ac87e6fda842b..05926b7f92809 100644 > --- a/Documentation/filesystems/fiemap.txt > +++ b/Documentation/filesystems/fiemap.txt > @@ -203,15 +203,13 @@ EINTR once fatal signal received. > > > Flag checking should be done at the beginning of the ->fiemap callback via the > -fiemap_check_flags() helper: > - > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); > +fiemap_prep() helper. Let's add the fiemap_prep() function prototype here. So that below description would make more sense. > > The struct fieinfo should be passed in as received from ioctl_fiemap(). The > set of fiemap flags which the fs understands should be passed via fs_flags. If > -fiemap_check_flags finds invalid user flags, it will place the bad values in > +fiemap_prep finds invalid user flags, it will place the bad values in > fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from > -fiemap_check_flags(), it should immediately exit, returning that error back to > +fiemap_prep(), it should immediately exit, returning that error back to > ioctl_fiemap(). Also maybe we should also add more info about fiemap_prep() helper. Since it also checks for invalid len and invalid start range and hence could return -EINVAL or -EFBIG. > > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 320d1062068d3..1f1ec361089b3 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -8250,7 +8250,7 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > { > int ret; > > - ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); > + ret = fiemap_prep(inode, fieinfo, start, &len, BTRFS_FIEMAP_FLAGS); > if (ret) > return ret; > > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > index 09047f1ddfb66..8a2e94931dc96 100644 > --- a/fs/cifs/smb2ops.c > +++ b/fs/cifs/smb2ops.c > @@ -3408,8 +3408,10 @@ static int smb3_fiemap(struct cifs_tcon *tcon, > int i, num, rc, flags, last_blob; > u64 next; > > - if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC)) > - return -EBADR; > + rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len, > + FIEMAP_FLAG_SYNC); How about d_inode(cfile->dentry) ? > + if (rc) > + rc; missed "return rc" here? > > xid = get_xid(); > again: > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index a41ae7c510170..41f73dea92cac 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -4908,8 +4908,9 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, > fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; > } > > - if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)) > - return -EBADR; > + error = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > + if (error) > + return error; > > error = ext4_fiemap_check_ranges(inode, start, &len); > if (error) > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 25abbbb65ba09..03faafc591b17 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1825,7 +1825,8 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > return ret; > } > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); > + ret = fiemap_prep(inode, fieinfo, start, &len, > + FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); > if (ret) > return ret; > > diff --git a/fs/ioctl.c b/fs/ioctl.c > index cbc84e23d00bd..4d94c20c9596b 100644 > --- a/fs/ioctl.c > +++ b/fs/ioctl.c > @@ -141,9 +141,12 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, > EXPORT_SYMBOL(fiemap_fill_next_extent); > > /** > - * fiemap_check_flags - check validity of requested flags for fiemap > + * fiemap_prep - check validity of requested flags for fiemap > + * @inode: Inode to operate on > * @fieinfo: Fiemap context passed into ->fiemap > - * @fs_flags: Set of fiemap flags that the file system understands > + * @start: Start of the mapped range > + * @len: Length of the mapped range, can be truncated by this function. > + * @supported_flags: Set of fiemap flags that the file system understands > * > * Called from file system ->fiemap callback. This will compute the > * intersection of valid fiemap flags and those that the fs supports. That Let's also add more documentation about this new fiemap_prep() helper. Earlier comments above this function description only talks about incompat flags. We should add more info about check_ranges part as well here. > @@ -154,48 +157,38 @@ EXPORT_SYMBOL(fiemap_fill_next_extent); > * > * Returns 0 on success, -EBADR on bad flags. > */ Also let's add ", -EINVAL or -EFBIG on invalid len or start range respectively" > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags) > +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, > + u64 start, u64 *len, u32 supported_flags) > { > + u64 maxbytes = inode->i_sb->s_maxbytes; > u32 incompat_flags; > > - incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags); > - if (incompat_flags) { > - fieinfo->fi_flags = incompat_flags; > - return -EBADR; > - } > - return 0; > -} > -EXPORT_SYMBOL(fiemap_check_flags); > - > -static int fiemap_check_ranges(struct super_block *sb, > - u64 start, u64 len, u64 *new_len) > -{ > - u64 maxbytes = (u64) sb->s_maxbytes; > - > - *new_len = len; > - > - if (len == 0) > + if (*len == 0) > return -EINVAL; > - > if (start > maxbytes) > return -EFBIG; > > /* > * Shrink request scope to what the fs can actually handle. > */ > - if (len > maxbytes || (maxbytes - len) < start) > - *new_len = maxbytes - start; > + if (*len > maxbytes || (maxbytes - *len) < start) > + *len = maxbytes - start; > > + supported_flags &= FIEMAP_FLAGS_COMPAT; > + incompat_flags = fieinfo->fi_flags & ~supported_flags; > + if (incompat_flags) { > + fieinfo->fi_flags = incompat_flags; > + return -EBADR; > + } > return 0; > } > +EXPORT_SYMBOL(fiemap_prep); > > static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > { > struct fiemap fiemap; > struct fiemap_extent_info fieinfo = { 0, }; > struct inode *inode = file_inode(filp); > - struct super_block *sb = inode->i_sb; > - u64 len; > int error; > > if (!inode->i_op->fiemap) > @@ -207,11 +200,6 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS) > return -EINVAL; > > - error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length, > - &len); > - if (error) > - return error; > - > fieinfo.fi_flags = fiemap.fm_flags; > fieinfo.fi_extents_max = fiemap.fm_extent_count; > fieinfo.fi_extents_start = ufiemap->fm_extents; > @@ -224,7 +212,8 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) > if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC) > filemap_write_and_wait(inode->i_mapping); > > - error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len); > + error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, > + fiemap.fm_length); > fiemap.fm_flags = fieinfo.fi_flags; > fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped; > if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap))) > @@ -312,7 +301,7 @@ static int __generic_block_fiemap(struct inode *inode, > bool past_eof = false, whole_file = false; > int ret = 0; > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c > index dd04e4added15..5e4e3520424da 100644 > --- a/fs/iomap/fiemap.c > +++ b/fs/iomap/fiemap.c > @@ -75,7 +75,7 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, > ctx.fi = fi; > ctx.prev.type = IOMAP_HOLE; > > - ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fi, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c > index 6e1aca38931f3..052c2da11e4d7 100644 > --- a/fs/nilfs2/inode.c > +++ b/fs/nilfs2/inode.c > @@ -1006,7 +1006,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > unsigned int blkbits = inode->i_blkbits; > int ret, n; > > - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); > + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); > if (ret) > return ret; > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > index e3e2d1b2af51a..3744179b73fa1 100644 > --- a/fs/ocfs2/extent_map.c > +++ b/fs/ocfs2/extent_map.c > @@ -746,7 +746,8 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, > struct buffer_head *di_bh = NULL; > struct ocfs2_extent_rec rec; > > - ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS); > + ret = fiemap_prep(inode, fieinfo, map_start, &map_len, > + OCFS2_FIEMAP_FLAGS); > if (ret) > return ret; > > diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h > index 240d4f7d9116a..4e624c4665837 100644 > --- a/include/linux/fiemap.h > +++ b/include/linux/fiemap.h > @@ -13,9 +13,10 @@ struct fiemap_extent_info { > fiemap_extent array */ > }; > > +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, > + u64 start, u64 *len, u32 supported_flags); > int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, > u64 phys, u64 len, u32 flags); > -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); > While we are at it, could remove this above additional line as well. > int generic_block_fiemap(struct inode *inode, > struct fiemap_extent_info *fieinfo, u64 start, u64 len, >
On Sat, May 02, 2020 at 04:19:05AM +0530, Ritesh Harjani wrote: >> -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); >> +fiemap_prep() helper. > > Let's add the fiemap_prep() function prototype here. > So that below description would make more sense. The annoying tendency to copy prototypes into docs just means they get out of date. Anyone who can't do a quick grep should not be writing code. I've added it back for consistency, but we really should remove all of them in this file. >> ioctl_fiemap(). The >> set of fiemap flags which the fs understands should be passed via fs_flags. If >> -fiemap_check_flags finds invalid user flags, it will place the bad values in >> +fiemap_prep finds invalid user flags, it will place the bad values in >> fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from >> -fiemap_check_flags(), it should immediately exit, returning that error back to >> +fiemap_prep(), it should immediately exit, returning that error back to >> ioctl_fiemap(). > > Also maybe we should also add more info about fiemap_prep() helper. > Since it also checks for invalid len and invalid start range and hence > could return -EINVAL or -EFBIG. I've added it. But this kind of documentation that just badly spells out what is done is not very useful. A quick look at the function conveys the information much better. >> --- a/fs/cifs/smb2ops.c >> +++ b/fs/cifs/smb2ops.c >> @@ -3408,8 +3408,10 @@ static int smb3_fiemap(struct cifs_tcon *tcon, >> int i, num, rc, flags, last_blob; >> u64 next; >> - if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC)) >> - return -EBADR; >> + rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len, >> + FIEMAP_FLAG_SYNC); > > How about d_inode(cfile->dentry) ? Ok. >> + if (rc) >> + rc; > > missed "return rc" here? Indeed. >> + * @start: Start of the mapped range >> + * @len: Length of the mapped range, can be truncated by this function. >> + * @supported_flags: Set of fiemap flags that the file system understands >> * >> * Called from file system ->fiemap callback. This will compute the >> * intersection of valid fiemap flags and those that the fs supports. That > > Let's also add more documentation about this new fiemap_prep() helper. > Earlier comments above this function description only talks about > incompat flags. We should add more info about check_ranges part as well > here. Seriously, the details are in the f^$^$ing code. No need to have an easily out of sync version of the code in the comment. I'll just radically shorten this.
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt index ac87e6fda842b..05926b7f92809 100644 --- a/Documentation/filesystems/fiemap.txt +++ b/Documentation/filesystems/fiemap.txt @@ -203,15 +203,13 @@ EINTR once fatal signal received. Flag checking should be done at the beginning of the ->fiemap callback via the -fiemap_check_flags() helper: - -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); +fiemap_prep() helper. The struct fieinfo should be passed in as received from ioctl_fiemap(). The set of fiemap flags which the fs understands should be passed via fs_flags. If -fiemap_check_flags finds invalid user flags, it will place the bad values in +fiemap_prep finds invalid user flags, it will place the bad values in fieinfo->fi_flags and return -EBADR. If the file system gets -EBADR, from -fiemap_check_flags(), it should immediately exit, returning that error back to +fiemap_prep(), it should immediately exit, returning that error back to ioctl_fiemap(). diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 320d1062068d3..1f1ec361089b3 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8250,7 +8250,7 @@ static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, { int ret; - ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); + ret = fiemap_prep(inode, fieinfo, start, &len, BTRFS_FIEMAP_FLAGS); if (ret) return ret; diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 09047f1ddfb66..8a2e94931dc96 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3408,8 +3408,10 @@ static int smb3_fiemap(struct cifs_tcon *tcon, int i, num, rc, flags, last_blob; u64 next; - if (fiemap_check_flags(fei, FIEMAP_FLAG_SYNC)) - return -EBADR; + rc = fiemap_prep(cfile->dentry->d_inode, fei, start, &len, + FIEMAP_FLAG_SYNC); + if (rc) + rc; xid = get_xid(); again: diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index a41ae7c510170..41f73dea92cac 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4908,8 +4908,9 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; } - if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)) - return -EBADR; + error = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); + if (error) + return error; error = ext4_fiemap_check_ranges(inode, start, &len); if (error) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 25abbbb65ba09..03faafc591b17 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1825,7 +1825,8 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, return ret; } - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); + ret = fiemap_prep(inode, fieinfo, start, &len, + FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR); if (ret) return ret; diff --git a/fs/ioctl.c b/fs/ioctl.c index cbc84e23d00bd..4d94c20c9596b 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -141,9 +141,12 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical, EXPORT_SYMBOL(fiemap_fill_next_extent); /** - * fiemap_check_flags - check validity of requested flags for fiemap + * fiemap_prep - check validity of requested flags for fiemap + * @inode: Inode to operate on * @fieinfo: Fiemap context passed into ->fiemap - * @fs_flags: Set of fiemap flags that the file system understands + * @start: Start of the mapped range + * @len: Length of the mapped range, can be truncated by this function. + * @supported_flags: Set of fiemap flags that the file system understands * * Called from file system ->fiemap callback. This will compute the * intersection of valid fiemap flags and those that the fs supports. That @@ -154,48 +157,38 @@ EXPORT_SYMBOL(fiemap_fill_next_extent); * * Returns 0 on success, -EBADR on bad flags. */ -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags) +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, + u64 start, u64 *len, u32 supported_flags) { + u64 maxbytes = inode->i_sb->s_maxbytes; u32 incompat_flags; - incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags); - if (incompat_flags) { - fieinfo->fi_flags = incompat_flags; - return -EBADR; - } - return 0; -} -EXPORT_SYMBOL(fiemap_check_flags); - -static int fiemap_check_ranges(struct super_block *sb, - u64 start, u64 len, u64 *new_len) -{ - u64 maxbytes = (u64) sb->s_maxbytes; - - *new_len = len; - - if (len == 0) + if (*len == 0) return -EINVAL; - if (start > maxbytes) return -EFBIG; /* * Shrink request scope to what the fs can actually handle. */ - if (len > maxbytes || (maxbytes - len) < start) - *new_len = maxbytes - start; + if (*len > maxbytes || (maxbytes - *len) < start) + *len = maxbytes - start; + supported_flags &= FIEMAP_FLAGS_COMPAT; + incompat_flags = fieinfo->fi_flags & ~supported_flags; + if (incompat_flags) { + fieinfo->fi_flags = incompat_flags; + return -EBADR; + } return 0; } +EXPORT_SYMBOL(fiemap_prep); static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) { struct fiemap fiemap; struct fiemap_extent_info fieinfo = { 0, }; struct inode *inode = file_inode(filp); - struct super_block *sb = inode->i_sb; - u64 len; int error; if (!inode->i_op->fiemap) @@ -207,11 +200,6 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS) return -EINVAL; - error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length, - &len); - if (error) - return error; - fieinfo.fi_flags = fiemap.fm_flags; fieinfo.fi_extents_max = fiemap.fm_extent_count; fieinfo.fi_extents_start = ufiemap->fm_extents; @@ -224,7 +212,8 @@ static int ioctl_fiemap(struct file *filp, struct fiemap __user *ufiemap) if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC) filemap_write_and_wait(inode->i_mapping); - error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, len); + error = inode->i_op->fiemap(inode, &fieinfo, fiemap.fm_start, + fiemap.fm_length); fiemap.fm_flags = fieinfo.fi_flags; fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped; if (copy_to_user(ufiemap, &fiemap, sizeof(fiemap))) @@ -312,7 +301,7 @@ static int __generic_block_fiemap(struct inode *inode, bool past_eof = false, whole_file = false; int ret = 0; - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); if (ret) return ret; diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c index dd04e4added15..5e4e3520424da 100644 --- a/fs/iomap/fiemap.c +++ b/fs/iomap/fiemap.c @@ -75,7 +75,7 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, ctx.fi = fi; ctx.prev.type = IOMAP_HOLE; - ret = fiemap_check_flags(fi, FIEMAP_FLAG_SYNC); + ret = fiemap_prep(inode, fi, start, &len, FIEMAP_FLAG_SYNC); if (ret) return ret; diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 6e1aca38931f3..052c2da11e4d7 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -1006,7 +1006,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, unsigned int blkbits = inode->i_blkbits; int ret, n; - ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC); + ret = fiemap_prep(inode, fieinfo, start, &len, FIEMAP_FLAG_SYNC); if (ret) return ret; diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c index e3e2d1b2af51a..3744179b73fa1 100644 --- a/fs/ocfs2/extent_map.c +++ b/fs/ocfs2/extent_map.c @@ -746,7 +746,8 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, struct buffer_head *di_bh = NULL; struct ocfs2_extent_rec rec; - ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS); + ret = fiemap_prep(inode, fieinfo, map_start, &map_len, + OCFS2_FIEMAP_FLAGS); if (ret) return ret; diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h index 240d4f7d9116a..4e624c4665837 100644 --- a/include/linux/fiemap.h +++ b/include/linux/fiemap.h @@ -13,9 +13,10 @@ struct fiemap_extent_info { fiemap_extent array */ }; +int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, + u64 start, u64 *len, u32 supported_flags); int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, u64 phys, u64 len, u32 flags); -int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); int generic_block_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len,
Replace fiemap_check_flags with a fiemap_validate helpers that also takes the inode and mapped range, and performs the sanity check and truncation previously done in fiemap_check_range. This way the validation is inside the file system itself and thus properly works for the stacked overlayfs case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> --- Documentation/filesystems/fiemap.txt | 8 ++--- fs/btrfs/inode.c | 2 +- fs/cifs/smb2ops.c | 6 ++-- fs/ext4/extents.c | 5 +-- fs/f2fs/data.c | 3 +- fs/ioctl.c | 53 +++++++++++----------------- fs/iomap/fiemap.c | 2 +- fs/nilfs2/inode.c | 2 +- fs/ocfs2/extent_map.c | 3 +- include/linux/fiemap.h | 3 +- 10 files changed, 40 insertions(+), 47 deletions(-)